The Engineering Projects

A starter kit is a pack of components. It provides everything needed to learn a particular activity. A starter kit is for helping beginners. It makes the initial steps simple. It provides the necessary tools, materials, or information for students. There are various types of starter kits. Kits are available for teaching electronics, hobbies, crafts, sports, and technology. They often include essential instructions. Sometimes starter kits come with educational resources. Their purpose is to make learning quick and easy. For DIY projects, a starter kit serves as a convenient entry point. They offer the necessary foundation and guidance to explore and engage in a new interest.

Why we need starter kits:

Starter kits make learning easy. Beginners cannot make a good parts list for learning. They can’t decide what to buy and what not. They often waste money on unnecessary goods. But they forget to buy the important parts. A complete starter kit makes this task easy. Lots of components come together in a starter kit. So, we need not roam here and there to buy them.

Starter kits come with user manuals. Some may include video tutorial DVDs. This helps learners a lot. They can learn a new topic with or  without any trainer.

Starter kits not only help beginners. Experts too can use these kits to complete their projects.

What is IoT?

IoT stands for Internet of Things. It's a network of devices, objects and systems. The 'things' of IoT can exchange data using the internet. In IoT, a 'thing' can even be a human being. Yes, you read it right. Let me tell you how:

Imagine, you're wearing a heart-rate sensor at home. IoT makes it possible for your doctor to monitor your heart rate from their chamber. Are you using a GPS tracker watch to track your kids? Yes, that's an example of IoT too.

IoT has brought a new revolution in technology. It's making life easier. Life has become more secure with IoT. You can live a tension-free life to some extent.

Suppose, you're on holiday. You have a garden. You need to water your plants. Who's gonna do that when you're not home? With IoT, you need not worry. You can make an IoT plant watering system. You need a controller. For example, an ESP8266. You need to connect it to the internet. You will also need a soil moisture sensor. The ESP8266 will read the sensor. Thus it will detect if the soil is dry or wet. The ESP8266 will control a water pump according to the sensor data. You'll need an IoT mobile app. You can receive the soil sensor data in your mobile app. You can also turn on the motor from your mobile phone.

Thus, you can control an IoT system from anywhere in the world. You can go to the US, still, you can switch off a motor, light or fan at your home in Berlin!

What are IoT kits?

An IoT kit is an electronics kit. It is a package of electronic components used for IoT projects. The heart of such a kit is a microcontroller board. Sensors, motors, LEDs etc. are also there. With these kits, you can do lots of IoT projects.

Where to buy?

You can buy IoT kits online. These are available at online electronics stores. SunFounder IoT kits has extended components as compared to other embedded starter kits. They have a large variety of easy to use IoT kits and their prices are also reasonable.

About SunFounder:

SunFounder is your one-stop solution for electronic projects. They sell Arduino and Raspberry pi boards and accessories.

Some Raspberry Pi products at Sunfounder

The company also offers Arduino and Raspberry Pi courses. The course instructors are very high-profile. You can find the details about the syllabus and instructors from their website as shown in the following image:

So, you can buy kits from them and also learn how to use them.

TOP IoT starter kits:

Here is a list of top IoT kits from Sunfounder:

1) SunFounder 3 in-1 IoT Starter Kit

SunFounder 3-in-1 IoT Starter Kit is a Versatile kit. This kit has 192 components. It includes an Arduino and an ESP8266. You can do lots of projects using the powers of these boards. It has all components to build a robotic car. Here are some significant projects that you can do with this kit:

• Door detection

• Window Detection

• Plant irrigation system.

You can build a smart car with this kit. The features of the car can be:

• Line tracking

• Obstacle avoidance

• Hand following

• Speed control and many more.

This kit provides 87 online tutorials for IoT and smart car related projects. Beginners and experts both can use this kit.

Features of SunFounder 3 in-1 IoT Starter Kit:

2) SunFounder Raspberry Pi Ultimate

SunFounder Raspberry Pi Ultimate kit comes with many Raspberry Pi accessories. The kit is versatile. It is suitable for both students and professionals. It has all the necessary software and hardware for a beginner. This kit gives access to 60+ video tutorials.

Features of SunFounder Raspberry Pi Ultimate :

3) SunFounder Raspberry Pi Pico W Starter Kit

This kit features a Raspberry Pi Pico W. The whole package is full of useful sensors. It is suitable for developing IoT devices.

Features of SunFounder Raspberry Pi Pico W Starter Kit :

4) Robotistan NodeMCU ESP8266 Kit

This is a NodeMCU-based kit. This is an ideal kit for understanding the fundamentals of IoT. It has 16 components. Those are LEDS, motors and various detection sensors. The kit gives a quick start to your IoT project. The NodeMCU is open-source. So, there is no need to use any extra board to use this kit. There is a manual with this kit. It discusses about all components in detail. You'll get a visual guide for circuit-building steps. Coding guideline is also there. An e-book is also available  for this kit users. That can help you further to made the project more advanced.

Features of  Robotistan NodeMCU ESP8266 Kit

5) OSOYOO ESP8266 NodeMCU IoT Starter Kit

This kit will teach you IoT in a fun and interactive way. It is suitable for making IoT-based school projects. Do you want to make a project for a science fair? You can depend on this kit. This kit is wifi supported. It uses the MQTT protocol. MQTT is a user-friendly protocol. The kit comes with a variety of open-source coding resources and mobile apps. It comes with a tutorial DVD. There are 17 video tutorials on that DVD. The tutorials consist of step-by-step guidelines. The codes are also tested. Detailed circuit diagrams help you do your project in the right way.

Features of  OSOYOO ESP8266 NodeMCU IoT Starter Kit:

6) ThingPulse #1 NodeMCU ESP8266 Starter Kit

ThingPulse #1 NodeMCU ESP8266 Starter Kit gives users a solid start to their IoT projects. It's a 4-in-1 wireless IoT development kit. It is a small kit. It is based on ESP8266. The kit has an OLED display. A DHT22 temperature and humidity sensor is there too. It also comes with a Data cable and some jumper wires. You can do the following projects with this kit:

• World clock

• Weather station

• Plane spotter

• Climate node

The kit comes with a 60-page guide. You will get premier customer support from the company for this kit.

Features of ThingPulse #1 NodeMCU ESP8266 Starter Kit:

7) KEYESTUDIO Smart Home Starter Kit

This is a very special kit. We often make IoT projects but we don't know how to apply them in our daily life. KEYESTUDIO Smart Home Starter Kit gives us the chance to apply our knowledge. With this kit, you can build a model smart home. The kit has laser-cut wood board for this task. The smart home consists of a control board, some sensors and actuators. The home is portable. You can power it up with 6 AA batteries. You can control your home with a mobile app.

Here are some of the projects possible with this kit:

• Door open-close

• Window open-close.

• Play music.

• Steam sensor on-off.

• Gas sensor on-off.

• Control switch and brightness of a light.

• Control switch and speed of the fan.

• Light on-off.

• Relay on-off.

Features of KEYESTUDIO Smart Home Starter Kit:

8) GAR Micro Starter Kit

This kit has Arduino UNO,an ESP8266 and an ESP32. ESP32 is a Wifi module. It also supports Bluetooth. So, it is a very powerful kit. This is suitable if you are looking for a micro starter kit. You can not only create wireless projects with this. ESP32, HC-05 allows you to experiment with various IoT concepts. This kit gives complimentary access to PDF guides and tutorial links. Those resources are available at the GAR Dropbox Cloud. The components come in a sturdy toolbox. It adds extra protection.

This kit needs no soldering. Total 18 sensors are there. Some of those are:

• Sound Sensor 

• PIR Motion Sensor 

• Impact Switch Sensor 

• IR Flame Sensor 

• Hall Effect Sensor 

• DHT11 Temperature & Humidity Sensor 

• MQ3 Alcohol Sensor 

• Soil Moisture Sensor 

• Rain Level Sensor

Features of GAR Micro Starter Kit:

9) Arduino MKR IoT Bundle:

Do you have this kit? You're only 5 steps away from building your smart home. Arduino MKR IoT Bundle is an exceptional IoT kit. It features an Arduino MKR board. You can control this board over the Internet. The kit has some sensors, ICs motors and LEDs. It helps users to make automation models. With this, you can learn the basics of IoT. This kit can connect online to the Arduino IoT cloud. Users gain access to the following services-

• Device programming.

• Data analytics.

• Control management.

• Automation triggering.

You can log, graph and analyze sensor data.

It comes with all the helpful parts. Such as data cable, LCD, battery connector etc.

Features of Arduino MKR IoT Bundle:

10) Arduino OPLA IoT Kit:

Are you a beginner or a professional? Well, it does not matter if you use Arduino OPLA IoT Kit. This kit is for all. It offers a user-friendly platform for IoT projects. You can make fully customized smart devices. Thanks to the open system. The following are the main components of this package:

• Arduino MKR Wi-Fi board.

• Arduino MKR IoT Carrier with an OLED display.

• 24 V relays.

• moisture sensors

• capacitive touch buttons

• SD card holder

• onboard sensors for light, temperature, and humidity.

This kit will also bring you 12 months of free access to the Arduino Cloud maker plan.

Features of Arduino OPLA IoT Kit:

Conclusion:

Sunfounder IoT kits are easy to use. These multipurpose kits give you the facility to learn IoT from scratch. You may have zero knowledge about IoT. Still, you are welcome to use these kits. We have discussed only 10 IoT kits in this article. The company manufactures many more exciting starter kits and robot kits.

Sunfounder has a forum too. In SunFounder Forum, you can share knowledge with others like you and can get help from their engineers.

So, why the delay? Check out these top-notch kits and start your journey to IoT. Wish you all the best.

Instagram has become one of the most popular social media platforms, with over a billion active users worldwide. This popularity has led to businesses and individuals using Instagram as a marketing tool to reach their target audience. However, gaining a substantial following on Instagram can take time and effort, especially for newcomers or those looking for rapid growth.

Many people turn to buying Instagram followers to speed up the process of gaining followers. To meet this demand, numerous platforms offer the option to buy Instagram followers. But with so many options available, it can take time to determine which platform is trustworthy and reliable. Here we will explore the top four platforms you can trust to buy Instagram followers, providing you with the essential information you need to make an informed decision.

What to look for in a platform to buy Instagram followers?

Before jumping into the platforms themselves, it's crucial to understand what to look for in a medium to buy Instagram followers. Here are some factors to consider:

• Quality of followers: Ensure that the platform provides active followers who engage with your content.

• Delivery time: Most platforms promise to deliver followers within 24-48 hours. Still, ensuring that the delivery time aligns with your goals and expectations is essential.

• Price: While choosing the cheapest option available may be tempting, remember that quality followers come at a price. Look for a platform that provides excellent value for money.

Top 4 Platforms to Buy Instagram Followers

1. Mixx

Mixx is a remarkable social media growth service that offers an array of Instagram followers and likes to boost your brand's visibility and revenue potential. With their years of experience and strategic expertise, Mixx provides powerful and impactful Instagram growth packages that ensure quick and safe results. Their commitment to authenticity sets them apart, using real accounts with unique addresses to fulfil orders.

With Mixx, you can expect instant delivery of followers, all from open accounts that provide long-term benefits. Their exceptional technical support is available 24/7, guaranteeing prompt assistance whenever needed.

Moreover, Mixx offers exclusive perks, affordable prices, and a focus on quality engagement, ensuring a safe and enjoyable growth experience. By partnering with Mixx, you can boost your Instagram earnings and explore various profit opportunities. As a top-rated agency, Mixx strives to set industry standards, providing exceptional value 

and support that surpasses other sellers.

2. SocialWick

Socialwick is a remarkable website that offers the opportunity to buy real Instagram followers, making it a game-changer for individuals and businesses seeking to enhance their social media presence. With their reliable services and high-quality followers, Socialwick provides a seamless experience and ensures genuine engagement. They offer a variety of packages tailored to meet different needs and budgets, allowing users to choose the one that suits them best. Whether you're an aspiring influencer or a growing business, Socialwick has the perfect solution. Their customer support is top-notch, assisting whenever needed. With Socialwick, you can boost your Instagram following, increase your brand's visibility, and unlock new opportunities for success. Embrace Socialwick today and watch your Instagram presence flourish with real and active followers.

3. SocialGreg

SocialGreg is a top-notch website that provides an exceptional service for boosting your Instagram following. If you want to maximize your influence on Instagram, this is the perfect platform. It offers accurate and authentic Instagram followers guaranteed to help you increase your reach and grow your following quickly and effectively. One of the best things about SocialGreg is its range of packages that cater to different needs and budgets. Whether you're looking for a quick boost or a longer-term growth strategy, they have something for everyone. Their packages are competitively priced and designed to deliver results quickly and efficiently.

The entire process of purchasing followers is simple. All you need to do is select the right package, enter your Instagram handle, and sit back and watch as your following grows. It's worth mentioning that SocialGreg is a safe and trustworthy platform for buying Instagram followers from. Unlike other services that sell fake or low-quality followers, SocialGreg only offers genuine and authentic followers. They also guarantee that their service won't get your account banned or suspended by Instagram, which is a huge relief for anyone who values their online reputation.

4. SubscriberZ

SubscriberZ is the ultimate solution for anyone looking to boost their Instagram presence. This website offers a wide range of packages to help you get real followers quickly and easily. Its service is straightforward, efficient, and reliable. When you purchase one of their packages, you can rest assured that you will receive real followers interested in your content. This is because SubscriberZ uses a unique marketing strategy that targets users likely to engage with your posts, resulting in a higher engagement rate and increased visibility. One of the best things about SubscriberZ is its variety of packages. Whether you're just starting on Instagram or an established influencer looking to take your account to the next level, SubscriberZ has a package that will suit your needs.

Overall, SubscriberZ is the go-to website for anyone looking to buy real Instagram followers. Their service is fast, reliable, and affordable, and their packages are designed to meet the needs of every type of user.

Conclusion

In the fast-paced world of Instagram, buying followers can be a game-changer for individuals and businesses striving to increase their online presence. While it's crucial to exercise caution and select a reputable platform. Buying followers is just one aspect of building a successful Instagram account. Although you should follow other pro marketing tips to get success , Combining organic growth strategies with the boost gained from buying followers can be a powerful strategy to accelerate your Instagram journey.

As you embark on your quest for Instagram success, always prioritize platforms that provide genuine, active followers who will contribute to your overall engagement. These top four platforms have proven their reliability and earned the trust of numerous satisfied customers. So why wait? Leap and watch your Instagram followers soar to new heights.

In today's digital age, where technology is an integral part of our daily lives, it's crucial to be aware of the various cybersecurity threats and take appropriate measures to protect ourselves.

While many people are familiar with the more well-known threats like phishing scams and malware, several commonly overlooked cybersecurity risks can have significant consequences. In this article, we will explore these threats and provide insights on how to overcome them.

What are the most important threats that we cannot afford to ignore?

One of the commonly overlooked cybersecurity threats is the vulnerability of public Wi-Fi networks. In an increasingly connected world, we often rely on public Wi-Fi hotspots in cafes, airports, and other public places.

However, these networks can be a breeding ground for hackers to intercept sensitive information such as passwords, credit card details, and personal data. This is where online protection measures come into play.

ExpressVPN’s India server is an excellent example of such protection measures. By using a virtual private network (VPN) service, individuals can encrypt their internet traffic and protect their online activities from prying eyes.

The India server specifically caters to individuals residing in India, offering them a secure connection that shields their data from potential threats. So whether you're accessing your bank account or browsing the web, using a VPN ensures that your information remains private and secure, even on unsecured public Wi-Fi networks.

Another often underestimated cybersecurity threat is the use of weak passwords. Many people tend to choose passwords that are easy to remember but also easy for hackers to guess.

Commonly used passwords such as "123456" or "password" make it incredibly easy for cybercriminals to gain unauthorized access to personal accounts. It is essential to create strong, unique passwords for each online account to overcome this threat.

A robust password should include a mix of uppercase and lowercase letters, numbers, and special characters. Additionally, a password manager can help generate and securely store complex passwords, eliminating the need to remember them all.

On the other hand, phishing attacks continue to be a significant concern in cybersecurity. These attacks involve tricking individuals into divulging sensitive information by posing as trustworthy entities, such as banks or popular online services.

Phishing emails often appear legitimate and include urgent requests for personal information, making it easy for unsuspecting users to fall into the trap. It's crucial to exercise caution and skepticism when encountering unsolicited emails or messages to protect against phishing attacks.

Our best advice: Verify the sender's identity, avoid clicking on suspicious links, and never share personal information through unsecured channels.

Some other threats to watch out for

While many individuals are vigilant about protecting their computers and smartphones, Internet of Things (IoT) according to Wired devices are frequently overlooked in cybersecurity.

IoT devices, such as smart home appliances, wearables, and medical devices, can be vulnerable to attacks if not properly secured. Changing default passwords on IoT devices and keeping them updated with the latest firmware and security patches is essential to mitigate this risk.

Additionally, segregating IoT devices on a separate network from other devices can prevent potential breaches from spreading.

Finally, social engineering attacks pose a significant threat that often goes unnoticed. These attacks involve manipulating individuals into divulging sensitive information through psychological manipulation and deception.

Attackers may impersonate trusted individuals or exploit personal information on social media platforms to gain the victim's trust. Because of that, it is crucial to be vigilant and exercise caution when sharing personal information online.

A tip: Limit the amount of personal information publicly available on social media platforms, and be wary of unsolicited requests for personal information.

The bottom line is that while we frequently focus on the more well-known cybersecurity threats, some other commonly overlooked risks can have serious consequences, and we need to remain vigilant.

Individuals can significantly improve their cybersecurity posture by utilizing online protection measures, creating strong passwords, staying cautious of phishing attempts, securing IoT devices, and being mindful of social engineering attacks.

In an increasingly interconnected world, it's crucial to prioritize cybersecurity and take proactive steps to protect our digital lives.

In the realm of electronics, the printed circuit board (PCB) serves as the foundation for countless technological advancements. PCBs connect and support various electronic components. They ensure seamless functionality and optimal performance. PCB prototyping plays a critical role in the development and testing of new designs before mass production. In this article, we will delve into the world of PCB prototyping. We will explore what it entails. We will also provide valuable insights on how to design and manufacture PCB prototypes effectively.

PCBWay is your one-stop solution for professional PCB prototyping services. With their cutting-edge technology and vast experience, they provide you with high-quality PCBs that meet your exact specifications. Whether you're a hobbyist or an entrepreneur, their dedicated team is committed to delivering excellence in every aspect of their PCB prototyping service.

They have a very user-friendly website. There you can place your order without any hassle. Below is what the website looks like:

PCBway provides a data-based, quality PCB prototyping service. Their service is available in more than 170 countries. They have a 98.3% on-time delivery rate. They process more than 2100 orders daily.

Here you can see some of their high-profile customers:

Table of Contents:

1. What is a PCB Prototype?

2. Importance of PCB Prototyping

3. Understanding the Design Process

   a. Schematic Capture

   b. PCB Layout Design

4. Selecting the Right Tools and Software

5. Design Guidelines for PCB Prototypes

   a. Component Placement and Routing

   b. Power and Ground Planes

   c. Signal Integrity and High-Speed Design Considerations

6. Manufacturing PCB Prototypes

   a. Fabrication Process

   b. Assembly Process

   c. Testing and Validation

i) DFM checks

ii) Design Rule Check (DRC)

7. Common Challenges and Troubleshooting

8. Best Practices for Successful PCB Prototyping

   a. Collaboration and Communication

   b. Iterative Design Approach

   c. Documentation and Version Control

9. Conclusion

1. What is a PCB Prototype?

A PCB prototype is a functional sample of a printed circuit board that serves as a proof-of-concept for a specific design. It allows engineers and designers to validate their circuit design, test its functionality, and identify potential improvements or issues before proceeding with mass production. PCB prototypes typically undergo rigorous testing and analysis to ensure their reliability, performance, and manufacturability. Prototyping is an essential step in the product development cycle as it helps to refine the design, reduce costs, and minimize risks associated with full-scale production.

2. Importance of PCB Prototyping

PCB prototyping offers numerous benefits and advantages throughout the product development cycle. It enables designers to visualize their circuit design, validate its functionality, and identify and rectify any design flaws or issues. By identifying and addressing these problems early on, costly mistakes can be avoided during mass production. Moreover, PCB prototyping allows for performance optimization, improved product quality, and reduced time to market.

Prototyping also provides an opportunity to evaluate different design alternatives and assess their feasibility and effectiveness. It helps designers gain a deeper understanding of the interaction between components, identify potential bottlenecks, and optimize the layout for better signal integrity, thermal management, and manufacturability.

3. Understanding the Design Process

The design process is a crucial aspect of PCB prototyping, encompassing schematic capture and PCB layout design.

a. Schematic Capture:

Schematic capture involves creating a graphical representation of the circuit design using specialized software tools. It involves selecting and connecting various electronic components to form a functional circuit diagram, capturing the electrical connections and relationships between components. During this stage, designers must consider factors such as the desired functionality, component availability, and compatibility.

The following image is an example of a schematic capture.

b. PCB Layout Design:

Once the schematic is finalized, the next step is to create the PCB layout design. This involves translating the circuit diagram into a physical representation of the PCB, positioning components, and routing traces to establish electrical connections. PCB layout design requires careful consideration of component placement. Designers should consider signal integrity, power distribution, and manufacturability too. Designers need to optimize the layout to minimize noise, ensure proper thermal dissipation, and facilitate ease of assembly.

Following is an example of a PCB layout:

4. Selecting the Right Tools and Software

To design PCB prototypes effectively, it is essential to choose the right tools and software. Numerous software packages are available that facilitate schematic capture, PCB layout design, and simulation. These tools offer features such as component libraries, design rule checks, and simulation capabilities, enabling designers to create accurate and optimized PCB prototypes.

When selecting tools, it is important to consider factors such as the complexity of the design, ease of use, availability of support, and compatibility with manufacturing processes. Popular software tools for PCB design include Altium Designer, Eagle, KiCad, and OrCAD, among others. Additionally, designers should also consider the availability of design resources, community support, and compatibility with the chosen PCB manufacturing service.

5. Design Guidelines for PCB Prototypes

To ensure the success of a PCB prototype, adherence to certain design guidelines is crucial. Consider the following aspects during the design process:

a. Component Placement and Routing:

Efficient component placement and routing contribute to optimal signal flow, reduced noise interference, and ease of assembly. Consider factors such as signal paths, thermal management, and component accessibility while placing and routing components on the PCB. Group components logically based on their functions and connections, and minimize the length and complexity of traces to avoid signal degradation and interference.

The following image shows a good arrangement of components.

b. Power and Ground Planes:

Proper allocation of power and ground planes helps ensure a stable power supply. It reduces noise and improves signal integrity. Implementing a multilayer PCB design with dedicated power and ground planes is often beneficial for high-speed and complex designs. Ensure that power and ground traces are sufficiently wide to minimize resistance and voltage drops, and employ vias to establish connections between different layers.

The image below shows the power and ground planes.

c. Signal Integrity and High-Speed Design Considerations:

For designs involving high-speed signals, careful attention must be paid to signal integrity. Consider factors such as impedance control, termination techniques, and signal routing to minimize reflections, crosstalk, and other signal integrity issues. Use controlled impedance traces for high-frequency signals, and employ techniques such as differential signaling and shielding to minimize electromagnetic interference (EMI).

The following picture shows Crosstalk Checking in PCB Layout for Signal Integrity Validation.

6. Manufacturing PCB Prototypes

Once the PCB design is complete, the next step is manufacturing the prototypes. The manufacturing process typically involves two main stages: fabrication and assembly.

a. Fabrication Process:

The fabrication process involves translating the PCB design into physical reality. It includes steps such as creating the PCB stack-up, applying the copper layers, etching, drilling, and applying surface finishes. Advanced fabrication techniques, such as advanced routing and via technologies, are employed to meet the design requirements. During the fabrication process, designers must consider factors such as the choice of substrate material, layer stack-up, copper weight, and surface finish to ensure the desired performance and reliability of the PCB prototype.

The following image shows the sequence of PCB fabrication:

b. Assembly Process:

During the assembly process, electronic components are mounted onto the fabricated PCB. This can be done through manual or automated processes, depending on the complexity and scale of the design. Once the components are placed, they are soldered onto the PCB, and any necessary inspections and tests are conducted. Designers must ensure proper component selection, compatibility with the manufacturing process, and appropriate soldering techniques to achieve reliable and robust connections.

PCBWay has PCB assembly capabilities.

The following picture shows the mixed 2-layer board assembly:

c. Testing and Validation:

After the assembly process, the PCB prototypes undergo rigorous testing and validation to ensure their functionality and performance. Various tests, such as functional testing, electrical testing, and environmental testing, are conducted to verify the design's reliability and adherence to specifications. Testing may include checking for short circuits, open circuits, component functionality, and signal integrity. Designers must work closely with the manufacturing partner to define the testing requirements and ensure that the prototypes meet the desired quality standards.

i) DFM checks

PCBway’s testing and validation process is excellent. All of a PCB's design specifications are examined by the DFM inspection. This check specifically searches for any features that might be troublesome, redundant, or missing altogether. Any one of these problems could have a significant negative impact on how well the project works in the end. For example, too less space between PCB components is a typical PCB design problem. This may cause Short circuit  and other issues.

DFM checks help save production costs and unanticipated expenses by spotting potential issues before manufacturing even starts. This is because fewer boards were scrapped as a result of these tests. This process can offer high-quality products at reasonable prices.

The following image shows the process of the DFM check.

ii)Design Rule Check (DRC):

DRC, which stands for Design Rule Check, is a critical step in the process of printed circuit board (PCB) design. It ensures that the PCB layout adheres to the specified design rules and constraints, minimizing the risk of errors and ensuring optimal performance of the final product. PCBway, a leading PCB manufacturing and assembly service provider, offers a comprehensive DRC service to its customers.

PCBway's DRC service is designed to meticulously examine the PCB design files, including the placement of components, routing of traces, and adherence to industry-standard design rules. By leveraging advanced software tools and experienced engineers, PCBway conducts a thorough analysis to detect potential design flaws, such as clearance violations, trace width violations, and pad-to-pad spacing violations. This comprehensive review helps identify and rectify any issues that could lead to manufacturing defects, electrical shorts, or signal integrity problems.

With PCBway's DRC service, customers can ensure that their PCB designs meet the highest quality standards. The service provides detailed reports highlighting the detected design rule violations, accompanied by suggested corrective actions. This enables designers to make informed decisions and make necessary modifications to their layouts, thereby enhancing the overall reliability and performance of the PCB.

Whether you are a professional PCB designer or a hobbyist, PCBway's DRC service offers a valuable resource to ensure your designs are error-free and ready for production. By partnering with PCBway, customers can confidently move forward with their PCB projects, knowing that their designs will be thoroughly validated and optimized for manufacturing success.

7. Common Challenges and Troubleshooting 

While designing and manufacturing PCB prototypes, several challenges may arise. Some common issues include component placement conflicts, electrical noise, signal integrity issues, thermal management problems, and manufacturability constraints. By employing systematic troubleshooting techniques and consulting experts when needed, these challenges can be effectively addressed.

For example, if there are signal integrity issues, designers can analyze the signal paths, adjust trace widths and impedances, and utilize termination techniques to minimize reflections and signal degradation. If thermal management becomes a concern, designers can optimize the component placement, employ heat sinks or thermal vias, and ensure proper airflow in the enclosure. Understanding the common challenges and having a systematic approach to troubleshooting will significantly contribute to successful PCB prototyping.

PCB boards can be improved through some simple methods. These methods also minimize cost increases. Some of these methods include:

• Voltage-resistant protection of rectifier diodes 

• Protection against electromagnetic interference caused by small relays

• Improvement on bonding pads shedding problem

And many more.

8. Best Practices for Successful PCB Prototyping

To ensure successful PCB prototyping, it is essential to adopt certain best practices throughout the design and manufacturing process:

a. Collaboration and Communication:

Efficient collaboration and communication between designers, engineers, and manufacturers are crucial. Clear communication of design requirements, specifications, and feedback ensures that all stakeholders are aligned, reducing the likelihood of errors or misinterpretations. Regular communication helps identify potential issues early on and promotes a smooth and streamlined prototyping process.

b. Iterative Design Approach:

Adopting an iterative design approach allows for continuous improvement and optimization of the PCB prototype. Iterative testing and feedback loops facilitate the identification and resolution of design issues, resulting in a more refined final product. By incorporating feedback from prototypes into subsequent design iterations, designers can refine the design, improve performance, and address any unforeseen challenges.

c. Documentation and Version Control:

Maintaining thorough documentation and version control throughout the design process ensures that design revisions, component changes, and test results are properly recorded. This documentation serves as a valuable reference for future iterations and aids in troubleshooting and design enhancements. Using version control tools and organizing design files systematically will prevent confusion and ensure that the most up-to-date design files are used during manufacturing.

9. Conclusion

PCB prototyping is an integral part of the product development cycle. It enables designers and engineers to refine their circuit designs, validate functionality, and identify and rectify issues before moving to mass production. By understanding the design process, selecting appropriate tools and software, following design guidelines, and incorporating best practices, designers can maximize the effectiveness of their PCB prototyping efforts. PCBWay's PCB prototyping service offers an excellent platform for designers to turn their ideas into reality and bring innovative products to market faster and more efficiently.

By leveraging the knowledge and resources available, designers and engineers can confidently embark on the journey of PCB prototyping, pushing the boundaries of technology and ushering in a new era of electronic innovation. The continued advancement of PCB prototyping techniques will undoubtedly contribute to the growth and success of the electronics industry, driving innovation and enabling the realization of groundbreaking ideas.

Welcome to the next tutorial of our raspberry pi four programming course. Before, we saw how to connect a Raspberry Pi 4 to a relay with four independent channels. To complement the relay circuit, we programmed a python script to turn on and off a single bulb. However, in this tutorial, we'll show you how to connect a GPS module to a Raspberry Pi 4.

Raspberry Pi 4, one of the most popular embedded platforms, has made it simple for developers to obtain location data via a GPS module, allowing them to create devices with a greater reliance on precise positioning. Because of the Raspberry Pi's impressive processing capabilities, this essay focuses on the exciting prospect of creating GPS-based projects using the same inexpensive GPS chips.

Since this project aims to retrieve location information (longitude and latitude) from a GPS module through UART and display it on a 16x2 LCD, this is yet another excellent chance to become acquainted with the 16x2 LCD and the Raspberry Pi.

Components

1. Raspberry Pi 4

2. Neo 6m v2 GPS Module

3. 16 x 2 LCD

4. Internet

5. Breadboard 

6. Jumper wires

7. Resistor or potentiometer

In addition, we'll install the GPS Daemon library and the 16x2 LCD Adafruit library later in this guide.

The Raspberry Pi 4 running Raspbian OS is being used in this example. You can find a rundown of the minimum necessary hardware and software in Raspberry Pi's introductory instruction.

How does a GPS module function?

The acronym "GPS" stands for "Global Positioning System," and it is used to determine the precise Longitude and Latitude of any point on Earth and the current UTC time. The core of every GPS tracking system is a GPS module installed in the vehicle. This gadget gets up-to-the-second satellite coordinates along with the time and date.

Using the NMEA protocol, a GPS module transmits a plethora of position-tracking data in real time, as shown below. The NMEA format includes multiple sentences, yet only one is necessary. Coordinates, time, and other pertinent data begin at $GPGGA in this phrase. This information is known as GPS Fix Data or Global Positioning System Geodetic Reference Frame Data. 

We can determine its coordinates by using a simple count of commas in the $GPGGA string. If you locate the $GPGGA string and place it in an array, you can get the Latitude value two commas later and the Longitude value four commas subsequently. These coordinates for longitude and latitude can now be used in other datasets.

The $GPGGA String and its explanation are listed below.

$GPGGA,HHMMSS.SSS, latitude, N, longitude, E, FQ, NOS, HDP, altitude, M, height, M,, checksum data

The GPS module

You can use the NEO-6MV2 as your own personal GPS receiver everywhere you go. The GPS receiver communicates with the satellite network to determine its precise location. The device then sends forth serial data representing its current location, including its latitude and longitude.

The NEO-6 module uses a ublox-6 positioning engine with 50 channels and a TTFF of one second. The massive parallel time-space searches are made possible by the two million correlators in this GPS engine. As a result, it can rapidly locate satellites. The module's compact size also makes it a good fit for portable electronics that run on batteries.

It takes a voltage between 2.7V and 3.6V to power the NEO-6M GPS modem. The NMEA protocols are used for the communication of GPS data. While NMEA is an industry-standard ASCII format, UBX is a proprietary binary format developed by u-blox.

Data can be transmitted using any I2C-compliant interfaces on the receiver chipset, including Universal Asynchronous Receiver Transceiver (UART), USB, SPI, or DDC. There are three configuration pins on the chip. Pin CFG-GPS0 is used to set the power mode at boot.

Choose between the NMEA and UBX protocols for transmitting GPS data using CFG COM0 and CFG COM1.

This module employs a NEO-6 modem that has already been configured for serial (UART) output and NMEA encoding GPS data.

By setting the config pins CFG COM0 and CFG COM1 to HIGH, the GPS data is transmitted via the NMEA protocol at 9600 bps. The above table demonstrates that the NMEA data in this setup contains GSV, RMC, GSA, GGA, GLL, and VTG signals.

Here is a pin diagram showing the module's four available channels:

The module's top update rate for its navigation system is 5 Hz. So, in no more than 0.2 seconds, a controller can retrieve the Gps coordinates from the modem.

The 32-second cold start, 23-second warm start, and 1-second hot start times are all measured when the modem is turned on. Getting the first GPS reading takes 32 seconds because the module is set up for a cold start.

The module includes an external antenna with a frequency of -160dBm. Both an EEPROM and real-time clock (RTC) are built into the module, and the module also features a battery for backup. Temperatures from -40 to 85 degrees Celsius are within the NEO-6M modem's operational range. 

Getting a Raspberry Pi set up for GPS communication

To get started, I'll assume you're familiar with the Raspberry Pi and know how to install an operating system, find your IP address, and launch a terminal app like PuTTY. If you have any questions or need assistance, please let me know in the comments area.

The most challenging aspect of this project is getting the Raspberry Pi 4 set up so that it can talk to the GPS module over UART; trust me, I know; this is the first time I've done it, and it took me a few tries to get it right.

Functioning of the UART in Communication

UART communication involves a one-to-one connection between two UARTs. One UART does the serial-to-parallel conversion for data coming from a CPU and then sends that serial data to another UART, which does the reverse for data coming into its receiving device. When connecting two UARTs, you must use two wires to send and receive data. As information is transmitted from one UART to another, it travels from the broadcasting UART's Tx pin to the receiving UART's Rx pin.

The bits sent out by the sending UART are not necessarily in sync with the bits sampled by the receiver UART since UARTs send data asynchronously. The transmitting UART appends the packet's start and stops bits rather than sending a clock signal. This information tells the receiving UART where to begin reading the data packet and where it should stop.

Once the receiving UART recognizes a start bit, it will begin decoding the incoming data at the pace determined by the baud rate. The speed of information transmission, in bits per second, is referred to as the "baud rate" (bps). The baud rate of both UARTs must be roughly equivalent. Bit timing inaccuracies can occur when the baud rate difference between the sending and receiving UARTs exceeds 10%.

The data packet structure being transmitted and received by both UARTs must be identical.

The data for transmission arrives on a data bus and is picked up by the UART. To communicate with the UART, devices like the CPU, RAM, and microcontroller use a data bus. The transmitting UART receives data in a parallel fashion from the data bus. The data packet is created when the transmitting UART takes the parallel data from a data bus and adds a stop bit, a parity bit, and a start bit. The packet's data is sent out serially, one byte at a time, through the Tx pin. A data packet is sent and received serially through the Rx pin on the receiving UART. The UART decodes the data and restores it to its original parallel format, discarding the stop bit, parity bit, and start bit along the way. The data packet is then transferred in parallel from the receiving UART to the data bus:

Data packets are the standard for transmitting information via UART. There is one start bit, five to nine data bits (determined by the UART), one or two parity bits, and one or two stop bits in each packet.

The Raspberry Pi includes a PL011 and a small UART as onboard UARTs. Because of the unique hardware building pieces they employ, their overall performance and other attributes will vary slightly. Contrarily, the raspberry pi's tiny UART is utilized for the Linux console output, while the PLO11 UART is linked to the wireless/Bluetooth module.

The PLO11's higher implementation level makes it the superior of the two UART options. Accordingly, we'll use an overlay in the most recent version of Raspbian OS to turn off the Bluetooth module on the PLO11 UART for this project.

Step 1: Update the Raspberry Pi

To get started on any new project, I always start by upgrading the raspberry pi. Therefore, let's do the standard procedure and execute the commands below;

sudo apt-get update

sudo apt-get upgrade

and then restart the computer using;

sudo reboot

Step 2: Set up the UART

Within this context, we will initially modify the /boot/config.txt file. Please use the following instructions to accomplish this:

sudo nano /boot/config.txt

Place the following lines at the end of the config.txt file:

dtparam=spi=on

dtoverlay=pi3-disable-bt

core_freq=250

enable_uart=1

force_turbo=1

You can leave with Ctrl+X and save with Y + Enter.

Incorrect settings could prevent your Raspberry Pi from starting up, so please double-check everything.

Why are we issuing these commands? Because force turbo causes UART to operate at its maximum core frequency, which we have set to 250 MHz. This is done to protect the reliability and validity of the received serial data. Force turbo=1 will now void your Raspberry Pi's warranty, but other than that, it's safe to use.

We are disabling Bluetooth on the Raspberry Pi 3 using the dtoverlay=pi3-disable-bt so that we may use the full power of the UART on ttyAMAO rather than the small UART on ttyS0.

The second step in configuring the UART is to modify the boot/cmdline.txt file.

Before making any changes to the cmdline.txt file, you should save a copy in case you need to revert to the original version. A few ways to accomplish this are;

sudo cp boot/cmdline.txt boot/cmdline_backup.txt

sudo nano /boot.cmdline.txt

Substitute the following for the current text;

dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles

save your work and exit.

After this is complete, another system reboot is required before the new settings may take effect (sudo reboot).

Step3: Disable the Pi 4 Serial Getty Service

Next, we'll issue a command that will block the Pi's serial getty service from starting automatically upon reboot:

sudo systemctl stop serial-getty@ttyS0.service

sudo systemctl disable serial-getty@ttyS0.service

If you ever need to turn it back on, use these commands.

sudo systemctl enable serial-getty@ttyS0.service

sudo systemctl start serial-getty@ttyS0.service

Reboot your pi 4.

Step 4: Activate ttyAMAO:

Now that ttyS0 is no longer active, we can turn on ttyAMAO.

sudo systemctl enable serial-getty@ttyAMA0.service

Step5: Install Minicom and pynmea2:

We'll establish communication with the GPS unit and decipher its readings using minicom. In addition, we will use it to ensure that our GPS component is functioning correctly. Daemon software GPSD is an alternative to minicom.

sudo apt-get install minicom

We'll employ the pynmea2 library to quickly and conveniently process incoming information. Installing it necessitates;

sudo pip install pynmea2

Step 6: Install the LCD Library:

The AdaFruit library will serve as the basis for this tutorial. While the library's primary target was AdaFruit displays, it can also be used with HD44780-based display boards. In such a case, your display should function normally.

The library should be cloned and installed immediately. to conduct a cloning run;

git clone https://github.com/adafruit/Adafruit_Python_CharLCD.git

Go to the location where the clone was made and install it.

cd ./Adafruit_Python_CharLCD

sudo python setup.py install

It's time for another restart so we can move on to plugging in the parts.

Circuit diagram

Referring to the schematic below, attach the GPS Module and the Liquid crystal display to the Raspberry Pi.

Connecting the GPS module to a Raspberry Pi is as simple as powering it from the 3.3V pin and grounding it via any other RPi ground pins.

Following this, link the module's transmit (TX) pin to the Raspberry Pi's receive (Rxd) UART pin (board pin 10).

Testing the GPS module

Before we jump into the python script, it's best to use minicom to verify the GPS module's connectivity. Type the command and hit Enter.

sudo minicom -D/dev/ttyAMA0 -b9600

Where 9600 is the baud rate the GPS module uses to transmit data. Once we have verified that our GPS and RPI can exchange data with one another and script development can begin.

Cat can also be used for the test.

sudo cat /dev/ttyAMA0

All of the previously discussed NMEA sentences will appear in Window. As shown in the figure below, a module's status LED will begin blinking if the GPS receiver detects satellites in the sky and begins to fixate on its location.

Now that everything has been set up, we can put it through its paces. Your GPS may need to be outside to acquire a good satellite lock (often, three or four are required; however, I was able to use mine indoors).

Complete code

import time

import serial

import string

import pynmea2

import RPi GPIO as gpio

#to add the LCD library

import Adafruit_CharLCD as LCD

gpio.setmode(gpio.BCM)

#declaring LCD pins

lcd_rs = 17

lcd_en = 18

lcd_d4 = 27

lcd_d5 = 22

lcd_d6 = 23

lcd_d7 = 10

lcd_backlight = 2

lcd_columns = 16 #Lcd column

lcd_rows = 2 #number of LCD rows

lcd = LCD.Adafruit_CharLCD(lcd = LCD.Adafruit_CharLCD(lcd_rs, lcd_en, lcd_d4, lcd_d5, lcd_d6, lcd_d7, lcd_columns, lcd_rows, lcd_backlight)

port = "/dev/ttyAMA0" # the serial port to which the pi is connected.

#create a serial object

ser = serial.Serial(port, baudrate = 9600, timeout = 0.5)

while 1:

    try:

        data = ser.readline()

    except:

print("loading") 

#wait for the serial port to churn out data

    if data[0:6] == '$GPGGA': # the long and lat data are always contained in the GPGGA string of the NMEA data

        msg = pynmea2.parse(data)

#parse the latitude and print

        latval = msg.lat

concatlat = "lat:" + str(latval)

        print concatlat

lcd.set_cursor(0,0)

lcd.message(concatlat)

#parse the longitude and print

longval = msg.lon

concatlong = "long:"+ str(longval)

print concatlong

lcd.set_cursor(0,1)

lcd.message(concatlong)

    time.sleep(0.5)#wait a little before picking the next data.

Output

Conclusion

This tutorial covered the basics of installing a GPS tracker on a Raspberry Pi 4. What we know about UART and the NMEA protocol has expanded as well. Numerous new possibilities for the exploration of the idea are now available. You could, for instance, construct a system for tracking vehicles, drones, or the weather. In addition to being inexpensive and simple to install, GPS modules are becoming increasingly popular. They can be frustrating because of their slow data extraction and spotty reception. However, they perform wonderfully in the open air. Next, we'll look at how to interface the BMP180 air pressure sensor to a Raspberry Pi 4.

Hello friends, I hope you all are doing well. Today, I am going to share the 8th tutorial of Section-III in our Raspberry Pi Programming Series. In the previous tutorial, we interfaced the temperature sensor DS18B20 with Raspberry Pi 4. In today's guide, we'll discover another temperature sensor BMP180 and will interface it with Raspberry Pi 4.

So, let's get started:

Project Description

In today's tutorial, we will interface the BMP180 sensor with Raspberry Pi 4 and will display the values of temperature, barometric pressure and altitude in the Raspberry Pi Console Window.

Components Required

We will use the following components in today's project:

• Raspberry pi 4
• BMP180 sensor
• Female-Female Jumper wires
• Breadboard

BMP180 Air Pressure Sensor

• BMP180 is a low-cost sensor designed by Bosch to measure the temperature and barometric pressure.
• As it can measure the pressure, so we can also get the altitude value from BMP180.
• It follows the I2C protocol to communicate with microcontrollers.
  
• Its a successor of the BMP085 sensor, a more accurate and precise model, shown in the below figure:
  

BMP180 Working Principle

Pressure can be measured with the BMP180 piezoresistive sensor. Semiconducting (often silicon) piezoresistive sensors respond to mechanical forces such as air pressure by shifting their resistance value.

Because air density changes with temperature, the BMP180 collects data on both pressure and temperature. Warmer air is less dense and lighter; therefore, it exerts less force on the sensor. Because the atmosphere at lower temperatures is thicker and heavier, it presses the sensor more. The sensor takes real-time temperature values to adjust for air density variations.

The BMP180 provides raw temperature (UT) and pressure(UP) readings. A reading of the pressure is taken after the temperature has been recorded. Measurement processing at the sensor is depicted in this flowchart:

The 11 individual calibration coefficients for the BMP180 are stored in the sensor's 176-bit EEPROM. Together with the UP and UT, these are needed to determine the actual atmospheric pressure and temperature. It takes some advanced algorithms to determine the exact pressure and temperature:

I2C Working Principle

I2C Protocol is designed to communicate between several devices with a single bus simultaneously. I2C uses the address frame for selecting a slave device to communicate.

Depending on the application, I2C slave addresses might be 7 or 10 bits in length. This requires sending not one but two addresses across the bus in two separate address frames. A specific 7-bit address of 0x92 is used for the first location. A second address frame, intended for 10-bit machines, comes just after the unique address. This is how devices with 10-bit addresses can coexist on a bus with devices having 7-bit addresses without causing any incompatibilities.

If you're using I2C, you can use either of its two unique slave-handling modes. Information can flow in both directions between the Master and the slave. I2C read/write bit comes immediately after the address bit. The Master sends a read bit to the slave by making the line high when it wants to accept data from the slave. A write bit is sent from the Master to the slave by grounding the connection.

The placement of the Raspberry Pi's I2C pins is depicted in the following diagram:

Install Python I2C Tools

First, you'll need to turn the I2C drivers on your Raspberry Pi.

Enter the raspi-config command as sudo. Select Menu Item #8 (Advanced Settings). Choose A7 I2C, confirm your acceptance when prompted to activate the I2C driver, then confirm your acceptance once more to load the drivers automatically. Return to the command prompt and type sudo reboot to restart your Raspberry Pi.

Be sure to include i2c-dev in /etc/modules.

sudo nano /etc/modules

After that, at the prompt, type:

sudo modprobe i2c-dev

Verify that i2c modules have been loaded and are functioning:

lsmod  | grep i2c

• Install some i2c tools:

I2c-tools has some neat programs like "i2cdetect", which lists all the slave devices on a bus by their addresses. To test it out, connect the sensor and run "sudo i2cdetect" with the -y parameter set to 1. In addition, "i2cdump" is a tool that may be used to determine the configuration of a single I2C device by reading its registers. Using the below connection details and the sensor's factory settings (address 0x77), you should see the following output:

The BMP180 has been detected on channel 77.

Circuit Diagram of BMP180 with Raspberry Pi 4

You only need a breadboard and some female-to-male jumper wires to hook up the sensor to your Pi 4. Before plugging in any peripherals, you should always shut down your Raspberry Pi. Type the following command and watch for the green LED to turn off:

sudo shutdown -h now

The BMP180 can be linked to a Raspberry Pi by following the instructions below. There are a few variations of the BMP180 boards, so keep that in mind. The BMP180 is the part number for the chip rather than the entire board; therefore, your board may have 4, 5, or 6 pins.

With the Raspberry Pi oriented as indicated above, the diagram below shows how the jumper wires should be connected.

• The red jumper connects the input VCC pin of the sensor to the 3v3 pin of the Pi 4.

• The yellow jumper connects the Raspberry Pi's SDA pin to the BMP180's SCL pin. This wire is used for communication between the BMP180 and the Raspberry Pi.

• Connecting the Raspberry Pi's SCL pin to the BMP180's SCL pin is a blue jumper wire that goes from the third pin on the top row to the right. i2c devices use the clock signal provided by this pin to synchronize their communication with the Raspberry Pi's clock.

• Any of the Raspberry Pi's ground (GND) pins can be connected to the BMP180's GND pin with the help of the black jumper.

Verify all wires are securely attached before powering up any devices. While it's doubtful anything horrible will happen, double-checking before pushing the button is still a good idea.

Python Code for BMP180 and RPi4

For Python to understand the BMP180's output, we must install the necessary libraries. The Adafruit libraries were initially developed to be utilized by BMP085, the BMP180's predecessor, but the compatibility between the chips means they can also be used with the BMP180.

Type this into the Raspberry Pi's shell to install the necessary Python and the libraries above.

sudo apt-get install build-essential python-dev python-smbus 

Please make a new Py file in your home directory and give it the name BM180.py. Then, paste the code below into the new file. The code is well-commented, so it shouldn't be too difficult to understand.

Complete code

import smbus

import time

# Get I2C bus

bus = smbus.SMBus(1)

# BMP180 address, 0x77(119)

# Read data back from 0xAA(170), 22 bytes

data = bus.read_i2c_block_data(0x77, 0xAA, 22)

# Convert the data

AC1 = data[0] * 256 + data[1]

if AC1 > 32767 :

AC1 -= 65535

AC2 = data[2] * 256 + data[3]

if AC2 > 32767 :

AC2 -= 65535

AC3 = data[4] * 256 + data[5]

if AC3 > 32767 :

AC3 -= 65535

AC4 = data[6] * 256 + data[7]

AC5 = data[8] * 256 + data[9]

AC6 = data[10] * 256 + data[11]

B1 = data[12] * 256 + data[13]

if B1 > 32767 :

B1 -= 65535

B2 = data[14] * 256 + data[15]

if B2 > 32767 :

B2 -= 65535

MB = data[16] * 256 + data[17]

if MB > 32767 :

MB -= 65535

MC = data[18] * 256 + data[19]

if MC > 32767 :

MC -= 65535

MD = data[20] * 256 + data[21]

if MD > 32767 :

MD -= 65535

time.sleep(0.5)

# BMP180 address, 0x77(119)

# Select measurement control register, 0xF4(244)

# 0x2E(46) Enable temperature measurement

bus.write_byte_data(0x77, 0xF4, 0x2E)

time.sleep(0.5)

# BMP180 address, 0x77(119)

# Read data back from 0xF6(246), 2 bytes

# temp MSB, temp LSB

data = bus.read_i2c_block_data(0x77, 0xF6, 2)

# Convert the data

temp = data[0] * 256 + data[1]

# BMP180 address, 0x77(119)

# Select measurement control register, 0xF4(244)

# 0x74(116) Enable pressure measurement, OSS = 1

bus.write_byte_data(0x77, 0xF4, 0x74)

time.sleep(0.5)

# BMP180 address, 0x77(119)

# Read data back from 0xF6(246), 3 bytes

# pres MSB1, pres MSB, pres LSB

data = bus.read_i2c_block_data(0x77, 0xF6, 3)

# Convert the data

pres = ((data[0] * 65536) + (data[1] * 256) + data[2]) / 128

# Callibration for Temperature

X1 = (temp - AC6) * AC5 / 32768.0

X2 = (MC * 2048.0) / (X1 + MD)

B5 = X1 + X2

cTemp = ((B5 + 8.0) / 16.0) / 10.0

fTemp = cTemp * 1.8 + 32

# Calibration for Pressure

B6 = B5 - 4000

X1 = (B2 * (B6 * B6 / 4096.0)) / 2048.0

X2 = AC2 * B6 / 2048.0

X3 = X1 + X2

B3 = (((AC1 * 4 + X3) * 2) + 2) / 4.0

X1 = AC3 * B6 / 8192.0

X2 = (B1 * (B6 * B6 / 2048.0)) / 65536.0

X3 = ((X1 + X2) + 2) / 4.0

B4 = AC4 * (X3 + 32768) / 32768.0

B7 = ((pres - B3) * (25000.0))

pressure = 0.0

if B7 < 2147483648L :

pressure = (B7 * 2) / B4

else :

pressure = (B7 / B4) * 2

X1 = (pressure / 256.0) * (pressure / 256.0)

X1 = (X1 * 3038.0) / 65536.0

X2 = ((-7357) * pressure) / 65536.0

pressure = (pressure + (X1 + X2 + 3791) / 16.0) / 100

# Calculate Altitude

altitude = 44330 * (1 - ((pressure / 1013.25) ** 0.1903))

# Output data to screen

print "Altitude : %.2f m" %altitude

print "Pressure : %.2f hPa " %pressure

print "Temperature in Celsius : %.2f C" %cTemp

print "Temperature in Fahrenheit : %.2f F" %fTemp

Output

Is it possible to use several BMP sensors on one board?

Usually, only one device on the I2C bus is assigned to address 0x77 because each device on the bus requires its unique address (etc.). It is possible to use numerous devices on the same address, but each device will demand its GPIO pin in exchange. This is useful if you connect multiple I2C devices to the same address, like the BMP085. By holding the XCLR pin low, you can force all devices on the I2C bus to reset while freeing the rest of the one you wish to read and making it respond to any request.

Predicting the weather with a pressure sensor

Forecasting the weather with changes in pressure sensors is possible. An increase in the amount of air above the surface of the Earth causes the barometric pressure to drop. As the air rises, it leaves a vacuum that creates a low-pressure zone on the ground. Air mass cools and condenses as it rises in height. The result is clouds that can eventually turn into the rain because of the condensation of atmospheric moisture. The wind is also often present as the surface air flows into low-pressure areas.

When air from higher in the stratosphere sinks to Earth, the result is a rise in atmospheric pressure. The air pressure beneath the surface is raised as the falling mass exerts pressure on the ground. The air mass is cooler and denser at lower altitudes, but at higher altitudes, it warms up and expands. Because of the low humidity of the heated expanding air, clouds are rarely seen during this weather phenomenon. In general, increasing barometric pressures precede the arrival of pleasant, bright days.

Conclusion

Here, we learned how to connect a BMP180 sensor to a Raspberry Pi 4. We have also researched the 12c protocol's operation to ensure successful sensor-to-pi 4 communication. Several tasks call for the interesting BMP180 sensor. Even though it has been retired from production, a comprehensive data sheet is still accessible online. The values provided by the module can be read and manipulated with only a basic shell script. Even though it's a major undertaking, learning to compile your kernel can help you better grasp Linux. The following tutorial will teach you how to connect the MQ-2 Gas Sensor with a Raspberry Pi 4.

Hello friends, I hope you all are having fun. Today, I am going to share the 9th tutorial of Section-III in our Raspberry Pi 4 Programming Course. In the previous tutorial, we interfaced an air pressure sensor BMP180 with Raspberry Pi 4. In this tutorial, you'll learn how to interface an MQ-2 gas sensor with a Raspberry Pi 4.

Many apartments, residences, and workplaces rely heavily on these gas sensors to detect smoke or gas and alert the appropriate personnel in an emergency. In addition to gas and smoke, this sensor is sensitive to various odorous gases.

Project Description

Today, we will interface a gas sensor MQ-2 with Raspberry Pi 4 and will display the values on Raspberry Pi Console Window.

Components Required

These are the components used in today's project:

• Raspberry Pi 4
• MQ-2 Smoke Sensor
• MCP3002 ADC

MQ-2 Gas Sensor Pinout

• MQ-2 is a low-cost electronic sensor, used to sense the intensity of gases in the surrounding.
• MQ-x(MQ-1 to MQ-9) is a family of gas sensors used to detect different kinds of gases in the environment i.e. methane, propane, hydrogen etc.
• The MQ-2 gas sensor is used in security systems to detect potentially dangerous gases or flammable smoke.
• MQ-x sensors are inexpensive, simple-to-operate with an extended sensing range that may be narrowed to control the level of sensitivity.

• The MQ-2 Gas sensor contains four inputs, two of which are reserved for Vcc and GND, and the remaining two can concurrently output digital and analog data.
• The image above reveals that the module incorporates two onboard LEDs. When power is provided to the board, the power LED lights up, while the Dout LED lights up when the potentiometer's trigger value is achieved.
• When an analog signal is received from the gas sensor, the board's integrated comparator OP-Amp converts it to a digital one.
• In addition, the device's sensitivity can also be fine-tuned using the included Trim-pot.

Now let's have a look at the Mq-2 Pinout:

MQ-2 Pinout

Here's the pinout diagram of MQ-2 sensor:

• Vcc: The VCC pin on the Gas Sensor is its power input and is connected to 5V.
• GND: The board's ground, denoted by the symbol GND, must be linked to the ground pin.
• Dout: Pin Dout is the board's digital output; a low reading indicates the absence of gas or smoke, while a high reading indicates its presence.
• Aout: The board's Analog output pin will provide an analog signal between the Vcc input and ground, denoted by the symbol "Aout", depending on the measured gas intensity.

How does the gas sensor function?

To correctly identify combustible glasses, the MQ-2 gas sensor employs a heating element; however, having such a component close to combustible gases would be catastrophic, so the sensor is built with anti-explosion protection consisting of two thin lines of stainless steel mesh, as can be seen in the image below. In this case, the stainless steel mesh houses the heating element.

Its mesh structure not only blocks out solids like dust and dirt but also keeps out particles in the air that are too big to be gaseous, such as oxygen and nitrogen. In this case, decapitating the sensor reveals that it consists of two main parts. The nichrome wire that does the heating is accompanied by a platinum wire that has been coated with tin dioxide for the sensing part. We have already removed the protective cap to prevent you from accidentally slicing your sensor, as shown in the figure below.

After the mesh is taken off, the sensor reveals its proper form. Stainless steel mesh was cut and attached to the sensor's housing, as shown in the top image. The sensory component that we have been discussing is now readily apparent. Since the actual detecting and heating element is attached to the sensor's six legs in a star configuration, the sensor's pins also take on that shape. Bakelite, used to increase the sensor's heat conductivity, is visible at the base of the device (black).

Module MQ-2 Gas Sensor Internal Design

Here is a pictorial representation of the circuitry inside the MQ-2 gas sensor module. This module's schematic is quite elementary, and its construction requires only a few essential parts. The following schematic could be helpful if you need to construct this circuit quickly:

The LM393 op-amp is shown in the diagram; it is a +5V-powered, low-power op-amp with a small offset voltage. The MQ-2 sensor requires at least 5V, so 3.3V can't be used to power the circuit. This op-amp is primarily responsible for performing the digital-to-analog conversion of analog input signals. In addition, the MQ-2 Sensor module's sensitivity and triggering voltage can be fine-tuned via an onboard 10K potentiometer. In addition, there are two LED lights. As soon as power is supplied to the board, the power LED lights up, while the trigger LED lights up when a predetermined threshold is met. A pair of decoupling capacitors helps keep the board quiet.

MQ-2 gas sensor preheating time:

It would be best if you let the gas sensor stabilize after being preheated before you can use it. Moreover, a 24-hour preheat period is specified on the device's datasheet. Does this indicate that it must be on for 24hrs before being used?

The resounding "NO" is the clear response to this inquiry. This only denotes that a continuous 24-hour run is required to acquire the typical performance figures in the datasheet. And after 24 hours in their lab, they measured it. To stay within tolerance, you must adhere to the specified preheating time of 24 hours. Considering the small space, the sensor should reach temperature equilibrium in under 30 minutes. Nevertheless, you may get results within a few percentage points of the datasheets in minutes.

Suppose you need a precise reading of the gas concentration. In that case, you should preheat your sensor for 24 hours, ensure it is properly calibrated, and find a way to account for ambient variables such as temperature and humidity.

With the MQ-2 Gas sensor, you can do more than detect the presence of butane and hydrogen gas; you can also measure the concentration of these gases in parts per million. Detecting the gas and determining its concentration in parts per million are two very different processes. Detecting a gas's level and subsequent increase in concentration is the primary subject of this essay. In addition, we will briefly touch on precisely calculating the gas concentration in parts per million, for which a different method is required.

Liquefied Petroleum Gas, Butane, and Hydrogen Detection Using the MQ-2

A can of LPG gas is shown above; when the gas is sprayed, the surrounding concentration of gas increases; repeating the process results in even higher gas concentrations. The multimeter will show an increase in the sensor's voltage reading as the gas concentration rises. Also, the module's green LED will illuminate when it hits the user-defined threshold.

Raspberry Pi MQ-2 Detector Circuit Diagram

The smoke sensor is powered by connecting pin 2 to the 5V connector and pin three to the GND terminal on pi 4. This provides the 5 volts that are required to power the smoke detector.

Our application will be set up to turn on the light when the smoke detector's voltage rises above a user-defined threshold.

Now that we've established the physical links, all that's missing is the software we've been developing.

Complete code

import RPi.GPIO as GPIO

import time

GPIO.setmode(GPIO.BCM)

GPIO.setwarnings(False)

GPIO.setup(14,GPIO.IN)

GPIO.setup(12,GPIO.OUT)

GPIO.output(12,False)

while True:

    button_state=GPIO.input(12)

    if button_state == False:

        GPIO.output(12,True)

        while GPIO.input(14) == False:

            time.sleep(0.2)

    else:

        GPIO.output(12,False)

Output

Conclusion

Follow the steps in this tutorial. You should be able to connect the MQ-2 sensor to a breadboard and a Raspberry Pi, turn on the SPI interface, and then read sensor values using the most recent Circuit Python library. You can accomplish the same thing for additional MQ-x sensors by modifying the file depending on the sensor's design and then connecting each sensor to a separate MCP3008 channel to read its values simultaneously. The following tutorial will teach you how to use a Raspberry Pi 4 with BLE to manage your household gadgets.

Image from: https://www.pexels.com/photo/a-person-holing-a-sticker-in-close-up-photography-11035380/

Programmers use different programming languages so that they can create front-end and back-end applications well. One of the people’s main choices is Node.js. This particular programming language allows the creation of applications using JavaScript.

What Exactly is Node.js?

Image from: https://www.pexels.com/photo/person-using-macbook-air-5496463/

Node.js is usually the choice of programmers because it is open-source. What does this mean? It means that the source code for it is readily available. Contributors from different parts of the world are maintaining the source code.

Node.js cannot be properly used without the right developer. A dedicated Nodejs developer is always in demand. More people are learning how to use this programming language. Yet, a person should always be interested, dedicated, and passionate about it.

Some Advantages of Node.js

Some programmers who are still searching for a programming language to focus on can start learning Node.js for the following advantages:

• This can be used for both the front-end and the back-end of the application. This means that programming can be done and fixed on both the client and server side.

• The community of this programming language has grown steadily over the past years. It is still expected to grow bigger and better with more contributions to help any Nodejs developer .

• The demand is only expected to grow as more well-known applications are using Node.js to improve their features.

Setting Up Node.js Development Environment

The first thing to do is to make sure that your account has administrator privileges. This means that you can choose the software that you want, download it, and install it on your device.

1. Download Node.js Installer – Make sure to download the latest version.

2. Install Node.js and NPM from your chosen web browser – The moment that download is complete, launch it. Follow the instructions that will be given to you.

3. Verify the installation of Node.js – A command prompt will enter and you need to place “node-v”

Choosing an IDE or Text Editor for Node.js

You may ask yourself what type of JavaScript IDE will you use for Node.js? Different text editors are available but these are some things that can help:

• Look for something that can be used by the whole node js development team. Some are more user-friendly than others.

• Find the IDE that can help with syntax highlighting.

• Refactoring options will always be very helpful. This will help you restructure the codes that you already have. It can make the editing of existing projects easier.

Basics of Node.js Programming

You can find react programmer that can make their knowledge and skills on providing what you need. Node.js is known for being event-driven and non-blocking which is confusing for people who haven’t learned enough about this yet.

When you say event-driven, it means that this can understand the request and do the task accordingly. A function will be created and will be registered instead of getting all the data. The function will work once it is triggered.

When you say non-blocking, it means that the request will be sent to the required function immediately. The request will not be blocked so it will be received at the soonest possible time.

Working with Modules, Callbacks, and Asynchronous Programming

When you say modules in Node.js, you are referring to a type of functionality that can be used in the Node.js application. Take note that the functionality can be simple or complex. It will depend on the number of JavaScript files that are available.

Callbacks, on the other hand, are the type of responses to an event. For example, when the user clicks on a button, the callback will make sure that something will happen. The application can take note that the same response should happen no matter who is using it.

Asynchronous programming works in such a way that other functions are already happening before the main function is done. This can make the response faster. To make this happen, Node.js needs to make use of the event loop that will dispatch the requests to C++. Once it receives the results, it will be sent back to JavaScript. This might seem long but this will only take a short time.

Building Web Applications with Node.js

Image from: https://www.pexels.com/photo/hand-holding-red-sticker-11035369/

The HTTP module can be used by the node.js programmer to get an immediate response. To do this, the programmer simply needs to use the createServer ( ) method. This will run whenever someone tries to use the same computer.

Other important things to note are the following:

• Routing – This is figuring out how the application will react to the client’s actions. Different routes are available and the route that the function will take depends on the action.

• Middleware – This will have all the access to request or respond to an object.

• Request Processing – You need to have the right command ready so that the request will be processed accordingly.

Working with Express.js

Express.js is the web application framework that is commonly used when you are using Node.js. This is the choice of a lot of people because it is simple yet flexible. Different features are available and they can be used for both apps and websites.

Setting Up Express.js

Remember that you cannot set up Express.js unless you already have Node.js on your device. Once this is done, you can do the following:

1. Create a directory and make sure that it is working.

2. Use the npim init command.

3. Enter the name of the main file.

4. Install Express in your directory.

Data Access and Database

Node js development can always be improved as long as all the bases are covered. To connect with the database, the programmer should have the appropriate drivers for it. The driver can be installed through a command prompt using the chosen text box. Once you have access, you will be able to go through your needed data.

The ORM can be used to represent the items that are available in the data. It will help you understand the relationship between the programs and the database. Some say that it is the layer that will hold all the information together.

Testing and Deployment

Unit testing is one of the most important things that programmers can do. This will ensure that even the smallest units are working properly. Each code will be isolated and tested so that if discrepancies are going to arise, these will be fixed. To make tests, some fake implementations will be inserted. The testers will check if the codes still react to those fake implementations.

There are different Node.js frameworks that you can choose from. Each framework has pros and cons. You need to consider the deployment options as well as how well the data will perform. You can choose from the following frameworks:

• Jasmine

• AVA

• Mocha

• Jest

Security and Best Practices

Image from: https://www.pexels.com/photo/unrecognizable-hacker-with-smartphone-typing-on-laptop-at-desk-5935791/

Different vulnerabilities will always threaten your database. One of the most common vulnerabilities is loose comparison. This happens when the attacker will create something that will make the condition to be always true. True values will be returned to the attacker which can make the data more vulnerable. If the database is tricked, data from the users of the database will be retrieved. The best thing to do is to use mixed data types.

Another common vulnerability is prototype pollution. This type of vulnerability allows the attacker to take control of the data. The tampered data will not work the way that it is supposed to. The best thing to do to counter this is to use the object.assign method. This will help retrieve the data from the user so that it will be updated and corrected.

We learned in the previous tutorial how to connect a joystick to a Raspberry Pi 4 using an mcp3008 and an op-amp IC, the LM324A. For each of the interface methods we studied, we created a python script allowing us to interact with the circuit. This tutorial will show you how to connect a 4-channel relay module with a Raspberry Pi to carry out switching.

A relay's primary function is to allow a circuit to be controlled by a weak signal. High-current applications necessitate relays to separate the low-voltage control circuit from the high-power driving circuits. Because of this, understanding it is crucial for those interested in industrial or household automation.

If you've been tinkering with a raspberry pi for a while, consider the various ways in which you might put it to use.

So let’s dive in!

Components

• Four-channel 5V Relay Module

• Raspberry pi 4 

• A Few Jumper cables 

• 5v power source

The raspberry pi has real-world uses, such as remotely turning a device on or off over the internet, sensors, or a mobile app communicating with the pi via Bluetooth. If we can master this, we will open up a world of possibilities.

Raspberry Pi as a Device Switch

Anybody who has experimented with a Raspberry Pi knows it has a GPIO.

The 40-pin general-purpose input/output (GPIO) connector is great for connecting various output devices. Since it is a digital computer, Raspberry Pi's GPIO pins can provide logic outputs. Logic 0 and 1 are the terms used to describe these two possible results from a logic circuit. If you write a program to make a Raspberry Pi pin write logic zero, you'll get a real-world GND potential. Likewise, when logic 1 is written on the Raspberry Pi pin, +3.3V is produced.

Logic 0 (gnd) and logic 1 (+3.3v) may be generated on any Raspberry Pi output pin with some programming. However, the output voltage is too low to power any real-world equipment. A maximum of 20 mA can be drawn from the output pin, as the 3.3V generated is currently limited. This only means that we can connect an LED straight to a Raspberry Pi gpio pin. In addition to the DC motor, no other output device can be connected directly to the raspberry pi's pin. Because of this, a different method is required when connecting an AC device.

How do relays work?

This image is a cross-sectional diagram of a relay's inner workings. A control coil encloses a core made of iron. When power is supplied to the control coil, an electromagnet begins to energize, boosting the strength of the magnetic field it produces. As a result, the top contact arm attracts the lower fixed arm, closing the contacts and completing the circuit. However, if the relay were de-energized before the connections were closed, the contacts would travel the opposite way, creating an open circuit. When the coil current is shut off, the spring will return the movable armature to its original position.

The operation of a relay is identical to that of a switch. This also means that the same principle applies. When a relay is used, one or even more poles are flipped. Each pole has two primary contact directions. They have NO contact, commonly known as the Normal Open Contact configuration. Connecting with someone is another name for this action. On activation, the relay completes the circuit. Once the relay is deactivated, the circuit is broken.

NC contact is short for normally closed contact. This is synonymous with the term "break contact." In contrast to "NO contact," communication will occur. By switching on the relay, the circuit is broken. As soon as the relay is turned off, the circuit is complete.

A relay's COM contact is shared by the normally closed (NC) and normally open (NO) contacts.

An example of a relay module with two channels is displayed here. As its name implies, a two-channel relay module consists of a circuit with two independent relays built in. This enables the simultaneous manipulation of two distinct gadgets. It follows that the greater the available channels, the more gadgets we can link together.

Let's connect the Pi 4 to the 2-channel relay now. With its four corresponding pins, the 2-channel relay may communicate with a Raspberry Pi. VCC, GND, IN1, and IN2 are the inputs. Current input higher than 30 mA and an input voltage of 5 V is required to power the relay module. As a result of this glaring current shortfall, we must rely on an external power source. Here, we'll employ the widely used MB102 Breadboard Power Supply, an external power supply board. If you're curious about this power source and why we decided to use it, there are some helpful links below. A 3.3 V Relay is what you'll need to operate with Relays without an external power supply.

The relay module's VCC pin must be connected to the power supply's 5 V pin. Then Join the Raspberry Pi 4's ground pin (GND) to the power supply's ground pin (GND). The next step is to attach a jumper wire between the power supply's second GND port and the Raspberry Pi's second GND port. As a result, the ground pin on the Pi 4, the relay switch, and the power source are now all connected. Last but not least, connect a push button to GPIO 2 to activate the relay. Let's connect a few high-powered gadgets across the relay's output now. As seen in the circuit schematic, a CFL is connected to the NC and COM ports.

Using a Relay as a Switching Circuit

As was previously mentioned, the RPi is a computer with an output range of only +3.3v to 0v. We need a dedicated electronic switching circuit to link any real-world device to the Raspberry Pi and enable it to switch. Assume throughout this lesson that you want to control an electrical lamp using raspberry pi. A switching circuit is required because we cannot wire the light bulb directly to the raspberry pi. There must be a switching circuit, such as a relay, to turn on and off AC appliances.

The following graphic depicts the internal structure of a relay.

Above, you can see that a basic relay has five connections. The electromagnetic coil's two ends, L1 and L2, serve as the magnet within the relay. Directly connecting the L1 Or L2 to a DC power supply is possible. The coil becomes an electromagnet when it is supplied with an electric current. Unlike the usually closed (NC) and ordinarily open (NO) terminals, the Common terminal can be moved.

Working of Relays

The NC terminal serves as the home of the common terminal, which is held in place using sprint tension. This is the relay's initial setting. In a standard setup, the NC and COM terminals of a relay are linked when the device is positioned on a flat surface. The coil becomes magnetized whenever a voltage is placed between coil terminals L1 and L2. The spring tension is opposed by the magnetic force that pulls the common terminal off of NC and onto NO. As long as the relay is live, there will be continuity between NO and COM. Magnetization ceases when the coil voltage is removed, and the common terminal reverts to the NC Terminal, as depicted below.

To conclude, we can switch any AC device on and off with a relay if we know how to do so effectively. However, the issue of activating the relay itself remains to be seen. Typically, relays require a voltage of 12v or 24v, which the Raspberry Pi cannot produce. A microprocessor cannot supply the 30-50mA current required for relays that operate on +5v coil voltage. Consequently, a relay switching circuit is required rather than a direct connection to the raspberry pi.

An explanation of relay control

By adjusting the voltage at the GPIO pins, you may toggle the state of any relay module, whether it's attached directly to the ports or via a relay HAT. Using Python in conjunction with the GPIO library is the simplest solution.

After establishing a connection to the desired GPIO pin, changing its state is as simple as issuing a single command in Python. Pins 26, 20, and 21 on the GPIO header are used for the Waveshare HAT relays. For this reason, for instance, the first relay's power supply can be switched after a delay of just one second.

Sample code

import time

import RPi.GPIO as GPIO

relay_ch = 26

GPIO.setwarnings(False)

GPIO.setmode(GPIO.BCM)

GPIO.setup(relay_ch, GPIO.OUT)

GPIO.output(relay_ch, GPIO.LOW)

time.sleep(1)

GPIO.output(relay_ch, GPIO.HIGH)

GPIO.cleanup()

Using a signal from a microcontroller like a Raspberry Pi, we can switch a DC load with a transistorized switching circuit. Just below, you'll find a quick breakdown of how transistors function.

Here is the complete circuit for using a transistor to switch a relay using a Raspberry Pi.

As demonstrated in the diagram above, the transistor controls the switching of the relay coil, while the relay terminals control the AC load. Any AC load can be connected to a Raspberry Pi using the circuit above and turned on or off remotely.

This setup makes use of the following Components:

• Q1 = It can be any regular NPN transistor; we chose a BC548.

• R1 = The resistor has a 330-ohm value.

• D1 = inexpensive switching diodes such as 4148

• RL1 = 12v Relay

Diode D1 is a protection device that allows the relay to be easily turned off, as shown in the diagram.

The transistor base resistor will receive the signal from the raspberry pi pin. Here's a program that will turn on a relay when the output is set to HIGH and turn it off when the output is set to LOW.

Sample code

led1 = 21 #GPIO pin to connect to relay

import RPi.GPIO as GPIO

import time

GPIO.setmode(GPIO.BCM)

GPIO.setup(led1, GPIO.OUT)

while True:

    GPIO.output(led1, True)    

    time.sleep(2)

    GPIO.output(led1, False)

    time.sleep(2)

The function of transistors in a relay module.

A transistor can open and close an electronic gate millions of times per second, allowing electrical signals to pass through and out. As long as electricity flows, the circuit is active; otherwise, it is cut off. Modern telecommunications systems are built on complicated switching circuits that rely on transistors. Circuits can also flip at extremely fast rates, with some offering switching speeds of over 100 billion on/off cycles per second or hundreds of gigahertz.

A logic gate, constructed from several transistors, compares input currents and generates a unique result. Logic gates allow computers to use Boolean algebra to make straightforward decisions. Modern computers and software applications are built on these methods.

Four-channel relay module

A relay module can be easily controlled by connecting its signal pin to the GPIO on a Raspberry Pi and then applying the rated input voltage from the power supply. The necessary transistors and switching circuitry are already on this board. All you have to do to use such a relay module is connect the GND of the power source that powers the relay module (5v/12v/24v) to the GND of the raspberry pi. 

Python code for a 4-channel relay

import RPi.GPIO as GPIO

import time

Relay_Ch1 = 26

Relay_Ch2 = 20

Relay_Ch3 = 21

GPIO.setwarnings(False)

GPIO.setmode(GPIO.BCM)

GPIO.setup(Relay_Ch1,GPIO.OUT)

GPIO.setup(Relay_Ch2,GPIO.OUT)

GPIO.setup(Relay_Ch3,GPIO.OUT)

print("Setup The Relay Module is [success]")

try:

while True:

#Control the Channel 1

GPIO.output(Relay_Ch1,GPIO.LOW)

print("Channel 1:The Common Contact is access to the Normal Open Contact!")

time.sleep(0.5)

GPIO.output(Relay_Ch1,GPIO.HIGH)

print("Channel 1:The Common Contact is access to the Normal Closed Contact!\n")

time.sleep(0.5)

#Control the Channel 2

GPIO.output(Relay_Ch2,GPIO.LOW)

print("Channel 2:The Common Contact is access to the Normal Open Contact!")

time.sleep(0.5)

GPIO.output(Relay_Ch2,GPIO.HIGH)

print("Channel 2:The Common Contact is access to the Normal Closed Contact!\n")

time.sleep(0.5)

#Control the Channel 3

GPIO.output(Relay_Ch3,GPIO.LOW)

print("Channel 3:The Common Contact is access to the Normal Open Contact!")

time.sleep(0.5)

GPIO.output(Relay_Ch3,GPIO.HIGH)

print("Channel 3:The Common Contact is access to the Normal Closed Contact!\n")

time.sleep(0.5)

except:

print("except")

GPIO.cleanup()

Though I only connected to a single module, adding three more lights to the 4-channel relay board is as simple as looping the live wire from module to module and sharing a common ground, as illustrated in the diagram below.

At this point, the raspberry pi 4 controls the 4-channel relay module. Closed-loop control for high-powered equipment is made possible by incorporating such code in considerably more complex scripts that consider human input or sensor readings.

Output

Conclusion

Due to human fallibility, it is necessary to install home automation systems to ensure electricity is used efficiently and safely wherever possible. As an intelligent platform, Raspberry Pi enables the interconnection and remote control of many home appliances over a single network infrastructure—specifically, the internet. Because of the convenience provided by these appliances.

Home automation systems are a promising new trend in appliance manufacturing to reduce energy use and human error. Raspberry pi-based automation is cutting-edge and innovative. Automating tasks is easier with a Raspberry Pi.

Tell me if you had trouble understanding it or connecting your relay module to your Raspberry Pi 4 in the comments. The next tutorial will teach you how to connect a GPS module to a Raspberry Pi 4.

Greetings, and welcome to the next tutorial in our series on programming for the Raspberry Pi 4. The previous tutorial showed us how to connect a 4x4 keypad to a Raspberry Pi 4. In the previous tutorial, we examined the inner workings of the 4-by-4 keyboard; in this one, we'll use the MCP3008 and the LM324 Op-amp IC to connect a joystick to the Raspberry Pi 4. The Joystick is the primary input device for many gaming systems. The Joystick we'll be connecting to the Raspberry Pi today plugs into a USB port, but there are plenty of situations when having access to the Pi's GPIO pins would be useful. We'll review the steps for preparing the circuit for each interface technique and creating a corresponding python script.

So let’s dive in!

Components

The hardware utilized in this instance is a Pi 4 running Raspbian. All the prerequisites for hardware and software have already been covered, and you can find them in the Raspberry Pi Introduction; other than that, we need:

• 1000µF capacitor

• MCP3008

• Joystick Module

• LM324 Op-amp IC

• 1KΩ resistor 

• LED

• 2.2KΩ resistor 

• Jumper wires.

Connecting an MCP3008 to a Raspberry Pi joystick

There is a wide variety of joysticks to choose from. In the diagram below, we see a common Joystick module. The Analog Outputs generated by this Joystick module often fluctuate in response to the orientation of the Joystick. Furthermore, we can determine the movement's direction by analyzing these voltage fluctuations with a microcontroller.

In my setup, pressing down on the Joystick toggles an on/off state for the button, so you may use any standard GPIO pin to connect yours. I'll connect it in the same way as the potentiometers, though.

You'll need to familiarize yourself with the Serial Peripheral Interface bus protocol and understand how to configure it on the Pi before connecting the analog controllers to the Pi with a little chip that employs SPI as a communication medium. You can find excellent guides on accomplishing this on the Pi 4 Spy website.

The SPI bus will be activated on specific GPIO pins, which will be the first thing you learn. In my experience, Method 1 (opening a config panel in Raspbian and choosing the SPI option) worked flawlessly. Then, you'll need to ensure the MCP3008 chip is wired properly. That will serve as the connection between your Joystick and the Pi. Pulse-width modulation is worth investigating if you want to change your RGB LED (PWM) colours.

Circuit diagram

In case you get stuck, I've included some screenshots and a layout of my setup below.

Input reading

Upon enabling SPI, you should have double-checked that pi-spyder was installed. That is required so that the analog device's input may be read. Setting the LED's colour to correspond with the Joystick's location on the RGB colour wheel may be fun. Let's pretend the X-axis is horizontal over Yellow and the Y-axis is vertical over Orange.

Code

import math

import RPi.GPIO as GPIO

import spidev

# Open SPI bus

spi = spidev.SpiDev()

spi.open(0, 0)

# Define sensor channels (3 to 7 are unused)

mcp3008_switch_channel = 0

mcp3008_x_voltage_channel = 1

mcp3008_y_voltage_channel = 2

# Define RGB channels

red_led = 36

green_led = 31

blue_led = 37

def read_spi_data_channel(channel):

    adc = spi.xfer2([1, (8+channel) << 4, 0])

    return ((adc[1] & 3) << 8) + adc[2]

def convert_coordinates_to_angle(x, y, center_x_pos, center_y_pos):

    dx = x - center_x_pos

    dy = y - center_y_pos

    rads = math.atan2(-dy, dx)

    rads %= 2 * math.pi

    return math.degrees(rads)  

def adjust_angle_for_perspective_of_current_led(angle, led):

    led_peak_angle = 90 if led == 'R' else (210 if led == 'B' else 330)

    return ((angle - led_peak_angle) + 360) % 360

def calculate_next_pwm_duty_cycle_for_led(angle, led):

    angle = adjust_angle_for_perspective_of_current_led(angle, led)

    if 120 < angle < 240:

        return 0

    elif angle <= 120:

        return 100 - (angle * (100 / 120.0))

    else:

        return 100 - ((360 - angle) * (100 / 120.0))

def is_joystick_near_center(x, y, center_x_pos, center_y_pos):

    dx = math.fabs(x - center_x_pos)

    dy = math.fabs(y - center_y_pos)

    return dx < 20 and dy < 20

def main():

    # Center positions when Joystick is at rest

    center_x_pos = 530

    center_y_pos = 504

    GPIO.setmode(GPIO.BOARD)

    GPIO.setup([red_led, green_led, blue_led], GPIO.OUT, initial=GPIO.LOW)

    pwm_r = GPIO.PWM(red_led, 300)

    pwm_g = GPIO.PWM(green_led, 300)

    pwm_b = GPIO.PWM(blue_led, 300)

    pwm_instances = [pwm_r, pwm_g, pwm_b]

    for p in pwm_instances:

        p.start(0)

    try:

        while True:

            # If the joystick switch is pressed down, turn off the LEDs

            switch = read_spi_data_channel(mcp3008_switch_channel)

            if switch == 0:

                for p in pwm_instances:

                    p.ChangeDutyCycle(0)

                continue

            # Read the joystick position data

            x_pos = read_spi_data_channel(mcp3008_x_voltage_channel)

            y_pos = read_spi_data_channel(mcp3008_y_voltage_channel)

            # If Joystick is at rest in the center, turn on all LEDs at max

            if is_joystick_near_center(x_pos, y_pos, center_x_pos, center_y_pos):

                for p in pwm_instances:

                    p.ChangeDutyCycle(100)

                continue

            # Adjust the duty cycle of LEDs based on the joystick position

            angle = convert_coordinates_to_angle(x_pos, y_pos, center_x_pos, center_y_pos)

            pwm_r.ChangeDutyCycle(calculate_next_pwm_duty_cycle_for_led(angle, 'R'))

            pwm_g.ChangeDutyCycle(calculate_next_pwm_duty_cycle_for_led(angle, 'G'))

            pwm_b.ChangeDutyCycle(calculate_next_pwm_duty_cycle_for_led(angle, 'B'))

            # print("Position : ({},{})  --  Angle : {}".format(x_pos, y_pos, round(angle, 2)))

    except KeyboardInterrupt:

        pass

    finally:

        for p in pwm_instances:

            p.stop()

        spi.close()

        GPIO.cleanup()

if __name__ == '__main__':

    main()

So that these methods' input, output, and goals are as apparent as possible, I've put in more effort than normal to comment on the code.

Output

Using OP-amp IC to interface the Joystick to pi 4

Both the X and Y axes are in use. A potentiometer, or "pot," is attached to each axis of the JOY STICK. Rx and Ry are the resulting midpoints of these pots. It follows that Ry and Rx are the movable centers of these kettles. While the Joystick is idle, Rx and Ry serve as voltage dividers.

The voltage at the Rx pin shifts as the Joystick is pushed along the horizontal axis. Similarly, the value at the Ry pin shifts as the device is tilted or turned vertically. The Joystick can be moved in four directions, with two ADC outputs. The voltage at each pin increases or decreases in response to the stick's orientation changes.

As is well-known, Raspberry Pi lacks any built-in Analog Digital Converter hardware. The Pi would be unable to recognize this module if it were attached directly. We shall employ comparators based on operational amplifiers to verify the voltage outputs. These OP-Amps send signals to the Raspberry Pi, and the Pi uses those signals to turn on and off the LEDs. Here, we've implemented a set of four LEDs to represent the four possible Joystick orientations. Please view the accompanying demonstration video.

All 17 GPIO pins have a maximum voltage rating of +3.3V, meaning that any outputs from the Op-amps must be less than that. We needed an op-amp that could operate at 3V, and the LM324 met both requirements. This IC's pins are a good match for the Raspberry Pi's GPIO connectors.

An explanation of operational amplifier circuits.

It has been said that operational amplifiers are the "workhorse" of analog circuits. The LM358 and the LM741 are widely utilized as the most popular varieties of Op-Amp IC. Many functions, such as an amplifier, integrators, differentiators, summers, voltage followers, and more, can be achieved with a single operational amplifier (Op-Amp) by altering the circuitry. Below is a list compiled by Circuit Digest of many Op-amp Circuits, each of which includes a tidy circuit diagram and a practical DIY hardware description to help you learn all about operational amplifiers.

General Operating Conditions of an Operating Amplifier

• When utilized in Open-loop mode, the Operational Amplifier (or "Op-amp" for short) can be a perfect amplifier with a typical DC gain of over 100,000 or 100dB.

• In its most fundamental form, an operational amplifier (Op-amp) is a three-terminal device with two inputs and a single output (excluding power connections).

• The power supply for an operational amplifier can be either a single DC voltage or a pair of supplies, one positive (+V) and one negative (-V).

• There can be "no current that flows through either of its two inputs" because of the operational amplifier's zero input offset voltage, V1 = V2, and its infinite input impedance, Z = infinity.

• Also, the output impedance of an operational amplifier is zero (Z = 0).

• Differential amplifiers, or op-amps, are voltage-sensing amplifiers that magnify the voltage difference between their input terminals by a fixed factor called Gain ( A ).

• Sometimes called "Open-loop Gain," (A) is a common measure of an amplifier's effectiveness.

• This open-loop gain can be considerably reduced and controlled by connecting the op-output amp to one of its input terminals to close the loop.

• There are two common ways to wire operational amplifiers, known as inverting and non-inverting.

LM324 circuit diagram

The LM324 IC includes four OP-AMP comparators to identify Joystick's four possible inputs. Here is the LM324 IC schematic straight from the datasheet.

The following circuit diagram shows the components that make up the Joystick module and the connections that allow it to communicate with the Raspberry Pi. All four comparators within the LM324 are denoted by the U1:A, U1:B, U1:C, and U1:D pins. In the circuit schematic, we have labelled the LM324 IC's comparator pins so that you can easily identify which one goes to which comparator.

Working Explanation

We have OP-AMP1 (or U1:A) and OP-AMP2 (or U1:B) for sensing Joystick motion in the Y axis, and OP-AMP3 (or U1:C) and OP-AMP4 (or U1:D) for sensing Joystick motion in the X axis.

OP-AMP1 picks up on the Y-axis downward movement of the Joystick:

The 2.3V (produced by a voltage divider circuit consisting of 1K and 2.2K) is attached to the negative electrode of comparator U1:A, while the positive terminal is wired to Ry. There is an increase in Ry voltage as the Joystick is moved downward along its Y axis. If the input voltage exceeds 2.3V, the OP-AMP will output +3.3V at the output Pin. In response to the OP-HIGH AMP's logic output, the Raspberry Pi will turn on and off an LED.

Joystick up, Y-axis, is detected by OP-AMP2:

The 1.0V (supplied by a voltage divider circuit consisting of 2.2K and 1K) is connected to the comparator U1: negative B's terminal, while the positive terminal is wired to Ry. As you raise the Joystick's Y axis, the voltage on Ry will drop. The OP-AMP output will go Low when this voltage falls below 1.0V. When the Raspberry Pi sees the LOW logic output from the OP-AMP, it will respond by turning on and off an LED.

With OP-AMP3, X-axis joystick motion to the left is detected:

The comparator U1: negative C's terminal is given 2.3V (1K and 2.2K via a voltage divider circuit), while the positive terminal is linked to Rx. Increasing Rx voltage occurs when the Joystick is moved to the left along its x-axis. If the input voltage exceeds 2.3V, the OP-AMP will output +3.3V at the output Pin. In response to the OP-HIGH AMP's logic output, the Raspberry Pi will turn on and off an LED.

OP-AMP4 recognizes an X-axis joystick movement to the right:

U1:4's negative terminal is given 1.0V (through a voltage divider circuit of 2.2K and 1K), while the positive terminal is linked to Rx. Rx voltage drops as the Joystick is moved to the right along its x-axis. The OP-AMP output will go Low when this voltage falls below 1.0V. When the Raspberry Pi sees the LOW logic output from the OP-AMP, it will respond by turning on and off an LED.

This allows Raspberry Pi to receive input from all four logic that controls the Joystick's four directions. Raspberry Pi uses inputs from these comparators to control the state of the LEDs. Here are the terminal outputs from our Raspberry Pi program, which also prints the Joystick's orientation to the screen.

A Python script is available below. The code is simple, and the comments make it easy to understand.

Complete code

import RPi.GPIO as IO    # calling for the header file, which helps in using GPIOs of PI

import time              # we are calling for time to provide delays in the program

IO.setwarnings(False)    # do not show any warnings

IO.setmode (IO.BCM)      #programming the GPIO by BCM PINs (like PIN29 as GPIO5)

IO.setup(21,IO.OUT)      # initialize GPIO21 as an output      

IO.setup(20,IO.OUT)

IO.setup(16,IO.OUT)

IO.setup(12,IO.OUT)

IO.setup(27,IO.IN)      # initialize GPIO27 as an input

IO.setup(4,IO.IN)

IO.setup(22,IO.IN)

IO.setup(17,IO.IN)

while 1:

    if (IO.input(27) == 0):  #If GPIO 27 goes low toggle LED on 21pin and print RIGHT

        IO.output(21,1)

        time.sleep(0.01)

        IO.output(21,0)

        print ("RIGHT")

    if (IO.input(4) == 1):   #If GPIO 4 goes high toggle LED on 20pin and print LEFT

        IO.output(20,1)

        time.sleep(0.01)

        IO.output(20,0)

        print ("LEFT")

    if (IO.input(22) == 0):  #If GPIO 22 goes low toggle LED on 16pin and print UP

        IO.output(16,1)

        time.sleep(0.01)

        IO.output(16,0)

        print ("UP")

    if (IO.input(17) == 1):  #If GPIO 17 goes high toggle LED on 12pin and print DOW

        IO.output(12,1)

        time.sleep(0.01)

        IO.output(12,0)

        print ("DOWN")           

Output

Conclusion

As we've seen in this guide, the Pi 4 computer lacks an analog input. The only data it can process is digital. Contrast it with the plentiful analog inputs of common microcontrollers like Arduino, AVR, or PIC. Many sensors produce analog outputs; therefore, we need a method to make the Pi analog-friendly. To that end, we have considered two alternatives. Connecting an MCP3008 microcontroller and an LM324 operational amplifier integrated circuit creates a "bridge" between analog and digital signals. If you have any questions regarding the setup or the code, or if you run into any problems, please let me know in the comments, and I'll do my best to help. The next article will teach you how to use a Raspberry Pi 4 to operate a relay board with four independent outputs.