Hello readers, I hope you all are doing great. This is the second tutorial of the Raspberry Pi programming series. In our previous tutorial, we discussed the basic features and hardware architecture of Raspberry Pi Pico.
In this tutorial, we will discuss the various available development environments for programming the Raspberry Pi Pico. Later, in this tutorial, we will also discuss the installation of Visual Studio Code for Pi Pico programming.
Fig. Raspberry Pi Pico
RP2040 supports multiple programming languages like C/C++, Circuit python, and MicroPython cross-platform development environments. Raspberry Pi Pico module consists of a built-in UF2 bootloader enabling programs to be loaded by drag and drop and floating point routines are baked into the chip to achieve ultra-fast performance.
There are multiple development environments to program a Raspberry Pi Pico board like Visual Studio Code, Thonny Python IDE and Arduino IDE etc.
We need to download and install some tools before installing the Visual Studio Code for programming Raspberry Pi Pico which includes:
Fig. CMake
CMake is an open-source system developed/designed to fulfill the need of powerful cross-platform build environment which is responsible for managing the build process in a compiler independent manner and in an OS (operating system. It is designed to work in conjunction with the native build environment.
CMake is responsible for generating a build environment for compiling a source code, building executables, creating libraries and generating wrappers.
It also supports dynamic and static library builds. It can handle complex hierarchies and applications dependent on several libraries. CMake can also handle projects with multiple toolkits or libraries, where each library is further having multiple directories.
CMake is open-source tool which is easy to use and also having a simple yet extensible design which can be extended (as per the requirements) to support new features.
Fig. 3 Windows 64-bit installer
Fig. 4 Press Next
Fig. 5 Accept Agreement
Fig. 6 Add path
The GCC ARM tool-chain is compatible with devices that are based on 32-bit Arm Cortex-A, Cortex-M, Cortex-R processors.
Fig. 7 Downloading ARM GCC tool-chain
Fig. 8 Download Python
Fig. 9 Add path and install
The next task is downloading and installing ‘Build Tools’ for Visual Studio Code. This tool is responsible for the command-line interface.
Fig. 10 Download Tool chain
Fig. 11 select the necessary tool
Fig. 12 installation
Git is an open-source tool responsible for code management. The main purpose of using Git is to track the changes in the source code or any set of files, which helps multiple developers work together on non-linear development. In simple words, we can say that Git makes a team of people or developers work together and that is too using common/same files. Toptal is a marketplace for top coders. Top companies and startups Hire Toptal’s freelance coders for their mission-critical software projects.
Fig. 13 Download Git for Windows
Fig. 14 Select necessary components
Fig. 15
Fig.16 Select the above highlighted choice
Fig. 17 “configure line ending conversions”
Fig. 18 configure terminal emulator
Fig. 19 “configure extra option”
Fig. 20 “Experimental support for pseudo consoles”
Once all the necessary tools (mentioned above) are successfully installed, we can download the Raspberry Pi Pico SDK and respective examples.
Before downloading the Pico SDK and Pico examples, we need to create a folder or directory to save the SDK and pico examples. So, we are creating a folder “RPi Pico” in C:\ drive.
Fig. 21 download Pico SDK
Fig. 22
Now we are ready to program Raspberry Pi Pico using Command Prompt.
Fig. 23 Developer Command prompt
Fig. 24
Fig. 25 create build directory
Using CMake to build the Makefiles:
Visual Studio Code is tool developed by Microsoft for source code editing.
Fig. 26 Download Visual Studio Code
Fig. 27 Accept the agreement
Fig. 28 Add to path
Fig. 29 Launch the Visual Studio code
Fig. 30 Visual Studio Code launched successfully
After successfully installing the Visual Studio Code, the next thing to do is to install CMake in VS code.
Steps to install CMake in Visual Studio Code are:
Fig. 31
Fig.32 setting
Fig. 33 CMake Configure Environment
Fig. 34 CMake generator
Fig. 35 Open folder
Fig. 36 Select ‘pico-examples’ folder
Fig. 37 GCC fro arm-none-eabi
Before writing a program for Raspberry Pi Pico make sure you have all the necessary hardware components along with the software and compilers (installed) required to program the Pico board.
This concludes the installation procedure for Visual Studio Code in Windows ( for Raspberry Pi Pico programming) which includes the installation of various tools and compilers necessary for programming Raspberry Pi Pico.
In our next tutorial, we will discuss the installation procedure of Python Thonny IDE for programming the Raspberry Pi Pico. We will also continue the programming part with Python Thonny IDE with MicroPython programming language.
I hope you found this tutorial of some help and also hope to see you soon with a new tutorial.
Before moving towards the detailed study of the Raspberry Pi Pico module, let’s first understand the traditional Raspberry Pi Computers.
Raspberry Pi is a single-board computer or a minicomputer. It was created with the goal of making computing knowledge more accessible to those who cannot afford laptops or desktop computers, as well as developing programming skills at a lower cost. The Raspberry Pi organization designed it.
The Raspberry Pi is a low-cost computer that includes some GPIOs (General Purpose Input-Output) for connecting to and controlling peripherals. Despite the fact that the Raspberry Pi's processing speed is much slower than that of desktop computers and laptop computers, it is still a computer with all of the processing and interfacing capabilities and low power consumption.
A Raspberry Pi can be used to create hardware, home automation, industrial applications etc.
There are various Raspberry Pi models available and Raspberry Pi Pico is one of them.
Fig. 1 Raspberry Pi Pico Vs Raspberry Pi Computer (Pi 0)
Raspberry Pi Pico is a completely different model or device than traditional Raspberry Pi models. Raspberry Pi Pico is not a Linux computer, but it is a microcontroller like various available Arduino boards.
It is a cost-effective development platform designed by Raspberry Pi which has enough processing power to handle complex tasks. It is a low-cost yet powerful microcontroller board with an RP2040 silicon chip.
Like the Raspberry Pi computer, Raspberry Pi Pico is also featured with a processing unit, GPIO (so it can be used to control and receive inputs from various electronic peripherals) etc. but it does not offer any wireless connectivity feature.
Other available Raspberry Pi boards like Raspberry Pi 0, Raspberry Pi 4, 3 etc. are similar to a traditional desktop computer. This means they have all the features to work as a computer like, an HDMI port to connect a monitor, USB ports for mouse and keyboard, SD card slot for OS etc.
But, Raspberry Pi Pico does not have any of the above features or capabilities, neither an HDMI port nor the USB for keyboard and mouse connectivity and instead of using an SD card for storage Pico model is featured with ‘Onboard flash memory’ to store programs.
So now you might have a doubt, that whether one can run a Raspberry Pi OS on a Raspberry Pi Pico or not? The answer is, NO. Unlike traditional Raspberry Pi modules, Raspberry Pi Pico doesn’t run a full desktop OS (operating system) but it runs code directly without a desktop interface.
If you have an Apple, Linux or Windows computer or even a different Raspberry Pi board (Pi 0, 4 or 3 etc.) then, you just need to plug the Raspberry Pi Pico into a computer to program the board for a specific task or project. Once the Pico is programmed successfully, it will run that code every time the board is powered ON.
So we can say that Raspberry Pi Pico is more like an Arduino board than a traditional Raspberry Pi model.
Fig. 2 Raspberry Pi Pico development board
Some key features of the Raspberry Pi Pico board are:
This module also offers an onboard buck-boost SMPS (switch mode power supply), which provides a flexible option for powering the board via a micro USB port, batteries or external supplies.
Along with various available peripheral interfacing modules and data communication capabilities, the Raspberry Pi Pico also offers, 8 PIO state machines, a USB 1.1 controller.
The Raspberry Pi Pico development board has been designed to use either a soldered 0.1" pin-headers or can also be used as a surface-mountable device (SMD) or module, as the user IO (input/output) pins are also castellated.
Raspberry Pi Pico comes with a dual-core microcontroller RP2040 chip, the chip is completely designed in-house at Raspberry Pi.
Fig. 3 RP2040 Microcontroller
RP2040 is the first microcontroller from Raspberry Pi. It is manufactured on a 40nm process node, which provided low power consumption capability and a variety of low power modes to offer extended duration operation on battery power.
The RP2040 microcontroller board consists of total of 36 GPIO pins but only 26 GPIO pins are exposed for control and interfacing.
Now let’s understand why this microcontroller is named so!
Fig. 4 RP2040 microcontroller
Some of the communication protocols or methods supported by the raspberry Pi Pico model are:
Like a Raspberry Pi computer, Raspberry Pi Pico also featured with GPIO pins to control & interface peripherals or to communicate data with peripherals and even to receive inputs and control signals from those peripherals.
Fig. 5 Raspberry Pi Pico Pin-out
The Raspberry Pi Pico pin-out reveals that it has 40 pins in total, including the power supply pins ( GND and VCC pins). PWM, ADC, UART, GPIO, SPI, I2C, debugging pins, and system control pins are the different types of pins.
Unlike the Raspberry Pi computer board series, the Pico board's GPIO pins serve multiple purposes and in total Raspberry Pi Pico has 26 multifunctional pins. These 26 multi-functional pins are marked as GP0, GP1, GP2 and so on. They can be used to perform both digital input and digital output functions.
For example, if we consider the GP4 and GP5 pins, they can be used as either a digital input or digital output, as can I2C1 (SDA and SCK pins) or UART1 (Rx and Tx). But, only one function can be used at a time by selecting a particular pin and providing the respective instructions in the code.
A 12- bit ADC is supported by the RP2040 Pico board and thus the ADC range can go from 0 to 4095.
The MicroPython code, on the other hand, can scale the ADC values to a 16-bit range. As a result, we have a range of 0 to 65535. Because the microcontroller operates at 3.3 V, an ADC pin will return a value of 65535 when 3.3 V is applied to it or 0 when no voltage is applied. When the voltage applied or the input voltage is in the range of 0 to 3.3 V, we can obtain all of the in-between values.
Fig. 6 Raspberry Pi Pico Communication protocols
The silkscreen labeling on the top side of the board provides an orientation for 40 pins, while a full pin-out is printed on the rear.
Raspberry Pi Pico comes with a USB 1.1 controller. This USB port is used to power up the board and program the Raspberry Pi Pico.
A BOOTSEL button is available on the Raspberry Pi Pico development board which means Boot Select. This button is used to put the board into USB mass storage mode while powering up the Pico board. This allows the user to drag and drop programs into the RPI-RP2 mounted drive.
An SWD which stands for Serial Wire Debug is provided for hardware debugging and letting the user quickly track the problems down in the program.
As we mentioned earlier, the Raspberry Pi Pico offers 2MB of on-board QSPI flash memory which can be programmed or reprogrammed via using either the SWD (or Serial Wire Debug) port or using a special USB mass storage device mode.
Raspberry Pi Pico module comes with an inbuilt temperature sensor. The sensor is internally connected to the ADC or analog to digital converter pins of the Raspberry Pi Pico board. These ADC pins, supports a range of values and that is determined by the input voltage applied to the pins.
Fig. 7 Programming Raspberry Pi Pico
There are multiple development environments available that support different programming languages to program the RP2040 microcontroller.
But, before writing a program for Raspberry Pi Pico you should have all the software and hardware components required to program the board.
The first thing required is a Micro-USB Cable, which allows the user to connect it to a computer or a Raspberry Pi for programming and powering up the Pico board.
The next component is the development environment required to compile and upload the program into the Raspberry Pi Pico development.
If you need to interface a peripheral with your Pico board using a breadboard then, you also need a set of Pico Headers.
RP2040 supports multiple programming languages like C/C++, Circuit python, MicroPython cross-platform development environments. Raspberry Pi Pico module consists of a built-in UF2 bootloader enabling programs to be loaded by drag and drop and floating-point routines are baked into the chip to achieve ultra-fast performance.
There are multiple development environments to program a Raspberry Pi Pico board like Visual Studio Code, Thonny Python IDE and Arduino IDE etc.
In our next tutorial, we will discuss the installation of the development environment for Raspberry Pi Pico and get started with the respective development environment.
So, this concludes the tutorial. I hope you found this of some help and also hope to see you soon with a new tutorial on Raspberry Pi.
to our new beginner’s course on Raspberry Pi. This course is appropriate for anyone using either a traditional Raspberry Pi board or the new Raspberry Pi 400 board that includes an integrated keyboard and display. Learning how to code, building robots, and doing plenty of other strange and exciting things are all possible with this low-cost computer setup. The Raspberry Pi can do everything a computer can do, from surfing the web to viewing movies and music, and playing video games.
Raspberry Pi is much more than a modern computer. It`s created to educate young people on how to program in languages such as Scratch and Python, and it comes with all of the major programming languages pre-installed. The world is in desperate need of programmers now more than ever, and Raspberry Pi has sparked a new generation's interest in computer science and technology. Raspberry Pi is used by people of all ages to build intriguing projects ranging from old-school gaming systems to internet-connected weather equipment.
| Where To Buy? | ||||
|---|---|---|---|---|
| No. | Components | Distributor | Link To Buy | |
| 1 | Raspberry Pi 4 | Amazon | Buy Now | |
In this course, we'll learn how to make games, build robots, or hack all kinds of fantastic projects. The Raspberry Pi 4 Model B will be covered in this course. In the event that you're working with a different model of Raspberry Pi, don't be worried. whatever is taught here can be applied to any other model in the family.
It is a small computer about the size of a credit card that can run the Linux operating system. It uses a "system on a chip," which combines the CPU, GPU, RAM, USB ports, and other components into a single chip.
To distinguish it from traditional computers that conceal their internal components behind a casing, the Raspberry Pi's ports and functions are fully exposed, a protective case is available to buy. If you want to know how different computer components work and where to put the various peripherals, this is a great resource.
All Raspberry Pi models share one feature in common:
Now you've got a little machine that runs a lot of free software, so that's good. Exactly what can you do with it? Fortunately, I've got a simple and fun Python project that I used to teach middle school children in a coding lesson.
The Raspberry Pi features a number of parts that can be used to control the Raspberry Pi as well as other devices. The following ports will be available on your Raspberry Pi:
The majority of the Raspberry Pi's system resides on an integrated circuit, which is what the term "system-on-chip" refers to. Included in this is the CPU, which is referred to as a computer's 'brain,' as well as the graphics processing unit (GPU).
A brain is useless without memory, therefore you'll notice another chip to the side of the SoC, tiny and black plastic, like a cube where RAM is located. When you're working on a Raspberry Pi, the RAM stores your work; it's only when you save it to the microSD card that it's written to the microSD card. The volatile and non-volatile memories of the Raspberry Pi are made up of these components. When the Raspberry Pi is turned off, the volatile RAM loses its contents, however, the non-volatile microSD card retains them.
A metallic lid covers the Raspberry Pi's radio component, which allows it to communicate wirelessly with other devices. In actuality, the radio has two main functions. Wi-Fi and Bluetooth are built-in, so you can use them to communicate with your computer and other nearby smart devices, sensors or cellphones.
Just behind the middle row of USB ports, an additional black, plastic-covered chip is seen towards the board's bottom border. The USB controller manages the four USB ports. The network controller is positioned next to this chip. An integrated circuit (PMIC) is also located on the upper left side of this board. It is in charge of converting power from a USB port to the precise voltage that the Raspberry Pi needs.
The circuit board contains a variety of ports, beginning with four ports in the right side of the bottom edge. You can connect any USB-compatible device to your Raspberry Pi using these ports, including keyboards, mice, digital cameras, and flash drives. One of the two types of USB ports is a USB 2.0 port, which uses version two of the USB standard; the other is a USB 3.0 port, which uses version three.
There is an Ethernet port. Using an RJ45 cable, a Raspberry Pi can be linked with a wired computer network via this port. You'll notice two LEDs at the bottom, which indicate the connection is operational.
There is a 3.5 mm audio-visual jack. Connecting to amplified speakers rather than headphone jacks improves sound quality, but the headphone jack can still be used. Audio and video signals can be transmitted using the TRRS (tip-ring-ring-sleeve) adapter, which connects the 3.5 mm AV jack with projectors, tv, and other displays that can receive composite video signals.
The camera serial interface (CSI), or camera connector, as it is most commonly called, is located above the AV jack and has a strange-looking plastic flap that may be pulled up (CSI). This allows you to connect a camera, which you'll learn later in this course.
There are two micro HDMI connections available, which are a scaled-down version of the connectors seen on gaming consoles, set-top boxes, and televisions. Multimedia denotes that it can transport both audio and video information, and high-definition indicates that the quality will be excellent. A computer monitor, television, or projector will be needed to connect the Raspberry Pi to these adapters.
The port above the HDMI ports is where you'll plug in the Raspberry Pi's power supply. USB Type-C ports can be found on smartphones, tablets, and other mobile devices. Instead of a standard mobile charger, employ the certified Raspberry Pi USB Type-C Power Supply for the best results.
There is a strange-looking connector at the top of the board, which appears to be the camera connector at first sight, but it's not. It is for usage with a Raspberry Pi Touch Display.
In two rows of 20 pins each, you'll find 40 metal pins along the right edge of the board. To communicate with peripherals such as LEDs and buttons to temperature sensors, joysticks, and pulse rate monitors, the Raspberry Pi includes a function known as GPIO (general-purpose input/output).
The Raspberry Pi has one more port, the micro-SD connector, which is on the other side of the circuit board. The MicroSD card is inserted here and you'll find all the files you've saved and installed as well as the operating system that makes your Raspberry Pi work.
Unfortunately, the Raspberry Pi lacks the ability to run either Macintosh or Windows. Instead, it uses Raspbian, a Linux distribution. Installing Raspbian on your own micro-SD card is also possible using the NOOBS installation. You'll see this loading screen when you insert in the microSD card with Raspbian installed and turn on the Raspberry Pi.
As you've seen, the desktop on your huge PC looks exactly like the one you are used to. A web browser, terminal, picture viewer, calculator, and a slew of other tools are all included by default.
The Raspberry Pi is the heart of your project, but without a power supply or storage, it won't be able to go very far. To get started, you'll need the following:
The power supply standard for the Raspberry Pi 4 has been upgraded from microUSB to USB-C, which is an improvement. Powering your Raspberry Pi is best done with a dedicated power adapter from the Raspberry Pi Foundation.
The later Pi models use microSD cards instead of the normal SD cards that were used in the original Pi models A and B. However, not all SD cards function correctly, therefore it's preferable to acquire a pre-loaded operating system with the original Raspberry Pi microSD card or a tested suitable card, such as the SanDisk Ultra 32GB.
This is technically optional, but we strongly advise it. It is a good idea to use a case to protect your bare board rather than leaving it exposed. The FLIRC case has a built-in heatsink, making it an excellent choice for older models of the Raspberry Pi.
You can control your Raspberry Pi using a keyboard and a mouse. Raspberry Pi can utilize almost any USB-connected keyboard and mouse, wired or wireless. However, don`t use 'gaming' keyboards with flashing lights since they consume too much power to be used successfully.
USB gamepads are also necessary when you are building consoles like a gaming rig, therefore, don't forget about them.
We are now going to set up our minicomputer therefore follow these simple steps to get yours up and running:
Congratulations! You've successfully assembled your Raspberry Pi! I hope you have something like this:
At this point in the course, we've learned about the Raspberry Pi computer and what each component does. Our minicomputer has now been set up, and in the next tutorial, we'll learn how to use the python programming language with the Raspbian operating system.
Welcome to the next lesson of our python programming class. In the last session, we looked at the use of If-else statements and created simple programs to demonstrate the concept. While loops are another type of conditional statement, and in this tutorial, we'll look at how they're used.
In this article, you'll learn how to prematurely exit a while loop, a Python control structure for endless iteration. You will also learn how to write conditions in a single line to produce short and readable code.
The term "iteration" refers to the practice of repeatedly running the same piece of code. A loop is a type of programming structure that implements iteration.
Both indefinite and definite iterations are recognized as valid programming constructs. Infinite iteration doesn't specify how many times the loop will be executed. As long as a condition is met, the chosen block will be executed again. An iteration that uses a definite iteration specifies how many times it will run the selected block.
While Loops are used to iterate over the same code block for an unlimited couple of iterations until a condition is met.
While Loops are used to repeat the same code block indefinitely until a condition is met, if a given Boolean condition is completed at the end of the block, the "do while" loop will continue to run a provided block of code, or it will not.
Only one statement is required for the Do While Loop to terminate. However, the While loop may terminate with no statements executed, while the While loop may terminate with statements executed.
This type of control flow statement specifies iteration, allowing the code to be executed again and again. When we know how many times we want to run a code section, a for loop comes in handy.
Here, we'll explore how the Python while statement can be used to build loops. We'll begin with a simple design and gradually add to it.
Listed below is a basic while loop's structure:
Block denotes an execution block that will be repeated over and over again. As with an if statement, this is indicated by indentation.
Indentation is used to define blocks in all Python control structures. See the previous tutorial on grouping statements for a refresher.
In the controlling expression, expr, variables are initialized and updated during the loop's execution.
In this case, the expr parameter is evaluated first in a Boolean context. If this is true, then the loop's body is run. The body is executed when the expression returns to true. The program moves to the topmost statement following the loop body if the condition in expr is false.
Take a look at the following loop:
This is what we're seeing in this case. n starts as five. The loop body is run because n > 0 is true. n is greater than 0. Line 3 of the loop body prints the value of n after decreasing by 1 to 4 places.
The expression is re-evaluated from the top of the loop after the loop's body has completed. Because it's still true, the code in the body runs once again, printing 3 on the screen.
It goes on like this until n equals zero. That is when the expression is tested, and the loop is broken. The program would typically restart execution from the top most statement following the loop's body, but there isn't one here.
It's worth noting that the controlling expression of the while loop is tested first. If the loop body is false at the start, it will never be executed:
Because of this, n is set to zero when the loop is encountered. There is no need for the loop body because the controlling statement n > 0 is false.
Below is another while loop that doesn't use the numeric comparison:
Lists evaluated in a Boolean context are either truthy or false, depending on whether or not they contain elements. As long as there are elements in it, a is true. The loop terminates when the list is empty and all items have been deleted using the pop () method.
The whole body of the while loop is executed each time it is executed. Python has two keywords, break and continue, to prevent a loop from repeating itself.
This statement breaks a loop completely and immediately in Python. Python performs the next statement in the program after the loop body, which ends the current loop iteration. As soon as an expression is evaluated, it is evaluated again to see if the loop will continue or end.
The following diagram illustrates the difference between the statements "break" and "continue":
Break.py is a Python script that demonstrates the use of the 'break' statement:
Using a command-line interpreter to run break.py yields the following results:
The break code is executed when n reaches the value of 2.0. Execution immediately moves to the print () call on line 7 after complete termination of the loop.
A continue statement replaces the break in the next script, continue.py.
The output is something like this:
When n is 2, the loop is terminated by the continue statement. Thus, the number 2 is omitted. The condition is re-evaluated at the top of the loop, and it is still true. As before, the loop terminates when n equals 0.
While loops in Python can have an optional else condition at the end. Unlike most other programming languages, Python has this unique functionality. Syntax in the form of a diagram:
The other clause's further statements will execute when the while loop completes, as shown in this example.
You may be wondering, "How is that useful?" at this point. After the while loop, you could insert the following statements directly after it:
Additional statements will be run regardless of whether or not the while loop is terminated.
An else condition will only execute if the loop stops "by exhaustion"—that is until the controlling condition is false; otherwise, no subsequent statements will be executed. If a break statement is used to break the loop, the else condition is not executed.
Think about the following scenario:
Variable n becomes 0, and therefore n > 0 became false. The loop's block runs until the condition is exhausted. The else clause is executed since the loop is allowed to run its course.
Consider the following example to see the difference:
The else condition is not executed because the loop is prematurely interrupted by the break.
The term else may appear to have a different meaning in the while loop then it does in the if statement. In order to make it more understandable, you may try one of the following:
You are free to disregard either of these interpretations if you don't find them helpful.
If you need to find a certain item on a list, this is a common scenario. If the item is discovered, you can use the break to leave the loop. Also, else condition can contain code to be run if the item is not found:
Assume you've written an infinite while loop. This may sound weird, right?
As an illustration, consider the following:
Ctrl+C, a keyboard interrupt, was used to end this code. There was no way this could have ended. The vertical ellipsis represented in this output has taken the place of several output lines that were omitted.
We're all going to be in a lot of trouble if True can ever be false. On the other hand, False creates an infinite loop that might conceivably run indefinitely.
However, this is a typical pattern, and it may not sound like something you would want to do. Code for a service that accepts service requests and operates indefinitely is a good example. In this situation, "forever" implies until you turn it off or the universe reaches the point of no return.
Alternatively, keep in mind that the break statement can be used to exit a loop. Instead of evaluating a condition at the top, conditions recognized within the loop body may make it easier to terminate the loop.
If you'd rather, you can use pop () to delete each item in the list in turn, as illustrated above:
Not a is true when a is empty, and the break statement terminates the loop.
Multiple break statements can be specified in a loop:
Breaking out of the loop at various points rather than trying to define every possible termination condition in the loop header is often preferable in situations like this.
Infinite loops can be convenient in some circumstances. It's important to remember that the loop must be stopped sometimes, or it will become limitless.
Generally, it is possible to nest Python control structures inside one another. Nested conditional statements, for example, are possible: if/elif/else.
The following code shows how a while loop can be nested inside of another while loop:
Nested loops are affected by statements like "break" or "continue" since they are nested within each other.
Loops can be nested in and out of the if/elif/else statements and the other way around.
All Python control structures can be mixed and matched to your heart's content. That is precisely how it should be. You can only nest while loops a maximum of four deep, which would be unpleasant if there were unforeseen constraints like these: 'A while loop cannot be embedded within an if statement.' Trying to recall them all would be nearly impossible.
Poor programming language design is evidenced by the presence of seemingly random numerical or logical constraints. Python, fortunately, does not have any.
You can specify a while loop in the same way you do an if statement: on a single line. If the loop body has many statements, semicolons (;) can be used to divide them:
To be clear, this technique only works with simple declarative. Compound statements cannot be combined in a single line. As a result, you can write an if statement on the same line as a while loop:
You can also do this:
Note that PEP 8 forbids the use of numerous assertions on a single line. "Since this is a bad idea anyway, you generally shouldn't do it too often.
The Python while loop was used in this tutorial to demonstrate indefinite iteration. You can now create sophisticated and straightforward while loops, thanks to the knowledge you've gained thus far. The else clause can be used in conjunction with a while loop to handle endless loops. If you've followed along, you should understand how to run the same code repeatedly. The next lesson will cover iteration with for loops with an explicit limit on the number of iterations.
Internet of Things is a system of multiple inter-related computing devices. The factor ‘thing’ in IoT is designated to an entity capable of communicating data over a network (IOT), which can be a digital machine, sensor, human being, animals etc. Each component that is included in IoT network is assigned with an unique identity called UID and the ability to communicate data over IoT network without any external human or computer intervention.
Hello readers, I hope you all are doing great. In our previous tutorial, we discussed how to upload data to Firebase Real-time Database using ESP32. In this tutorial, we will learn how to read the data stored on the Firebase Database with ESP32.
We can access the data stored in Firebase database from anywhere in the world, which makes this preferable in IoT applications.
| Where To Buy? | ||||
|---|---|---|---|---|
| No. | Components | Distributor | Link To Buy | |
| 1 | ESP32 | Amazon | Buy Now | |
In our previous tutorial, we learnt how to upload an integer value (for demonstration) to Firebase real-time database. So, in this tutorial we will learn how to fetch or receive those integer values from Firebase database.
To access real-time data, we are using two ESP boards where one is used to upload/store the real-time data to the Firebase database and another to read the data stored on the firebase.
Although, it is not required to use two ESP boards, we can also access the previously saved data on the Firebase database with only a single ESP32/ESP8266 board.
We can use the same code for both ESP32 and ESP8266 but we need to make some changes like some of the libraries will be different for ESP8266 and the selection of ESP8266 development board while uploading the code with Arduino IDE.
Fig. 1 Reading data from firebase
Google's Firebase real-time database is a development platform that includes a number of services for managing and authenticating data.
Firebase is a mobile and web app development platform (that also works well with Android APIs) that includes features such as Firebase Cloud, real-time data, and Firebase authentication, among others.
According to Firebase's official documentation (https://firebase.google.com/docs/database), when a user creates a cross-platform application using JavaScript SDKs for Android or Apple, all clients share a single database.
Fig. 1 Firebase Real-time database and ESP32
The following are the main features of the Firebase Real-time database:
The Internet of Things, also known as IoT, is the interconnection of physical objects or devices with sensors and software accessing capabilities in order to communicate data or information over the internet.
We need an interface medium that can fetch, control, and communicate data between sender and receiver electronics devices or servers in order to build an IoT network.
The Firebase real-time database gives you a place to store data from sensors on your level device. With Android APIs, Firebase performs admirably.
Firebase is especially useful for storing data from sensors and syncing it between users in real-time in data-intensive Internet of things (IoT) applications. For the sake of simplicity and clarity, we can say that it is a Google cloud service for real-time collaborative apps.
We are using Arduino IDE to compile and upload code into the ESP32 module. You must have ESP32 board manager installed on your Arduino IDE to program the ESP32 module. To know more about Arduino IDE and how to use it, follow our previous tutorial i.e., on ESP32 programming series. The link is given below:
https://www.theengineeringprojects.com/2021/11/introduction-to-esp32-programming-series.html
Fig. 2 manage libraries
Fig. 3 Install Firebase ESP Client Library
We have already posted a tutorial on our website on getting started with Firebase real-time database and how to post or upload data to Firebase database from ESP32. Where we discussed, how to create a project on Firebase real-time database, authentication, how to access the API key and project URL etc.
So now we do not need to create a new project, we are using the same project and hence same API key and project URL to read or download the data from Firebase real-time database.
Fig. 4 Project Setting
Fig. 5 Project API key
Fig. 6 Project URL
//--add necessary header files
#include <WiFi.h>
#include <Firebase_ESP_Client.h>
#include "addons/TokenHelper.h" //Provide the token generation process info.
#include "addons/RTDBHelper.h" //Provide the real-time database payload printing info and other helper functions.
// Insert your network credentials
#define WIFI_SSID "ssid"
#define WIFI_PASSWORD "password"
// Insert Firebase project API Key
#define API_KEY "replace this with your project API key"
// ----Insert real-time database URL
#define DATABASE_URL "replace this with your project URL"
//Define Firebase Data object
FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;
unsigned long sendDataPrevMillis = 0;
int read_data;
bool signupSuccess = false;
void setup() {
Serial.begin(115200);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
Serial.print("Connecting to Wi-Fi");
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(200);
}
Serial.println();
Serial.print("Connected to... ");
Serial.println(WiFi.localIP());
Serial.println();
// Assigning the project API key
config.api_key = API_KEY;
//Assign the project URL
config.database_url = DATABASE_URL;
/// check signup statue
if (Firebase.signUp(&config, &auth, "", "")) {
Serial.println("ok");
signupSuccess = true;
}
else {
Serial.printf("%s\n", config.signer.signupError.message.c_str());
}
// Assign the callback function for token generation task
config.token_status_callback = tokenStatusCallback;
Firebase.begin(&config, &auth);
Firebase.reconnectWiFi(true);
}
void loop()
{
if (Firebase.ready() && signupSuccess && (millis() -
sendDataPrevMillis > 8000 || sendDataPrevMillis == 0))
{
sendDataPrevMillis = millis();
if (Firebase.RTDB.getInt(&fbdo, "/test/int"))
{
if (fbdo.dataType() == "int")
{
read_data = fbdo.intData();
Serial.print("Data received: ");
Serial.println(read_data); //print the data received from the Firebase database
}
}
else
{
Serial.println(fbdo.errorReason()); //print he error (if any)
}
}
}
Fig. 7 Header files
Fig. 8 Helper libraries
Fig. 9 Insert API key
Fig. 10 RTDB URL
Fig. 11 Firebase Data Objects
Fig. 12 Enter Network credentials
Fig. 13 Initialize wifi module
Fig. 14 Fetch/obtain the IP address
Fig. 15 configuring API key
Fig. 16 configuring database URL
Fig. 17 sign up status
Fig. 18
Fig. 19 Fetch data from Firebase RTDB
Fig. 20
Fig. 21 Select development board and COM port
Fig. 22 Data sent Vs Data Received
This concludes the tutorial. I hope you found this of some help and also hope to see you soon with a new tutorial on ESP32.
Welcome to the fifteenth chapter of this python course. Python lists and tuples were studied extensively in the last session, and we learned how to manipulate the data contained in these types of structures. You've only experienced sequential execution up to this point, where each statement is performed sequentially in the order they appear in the code.
However, the real world is frequently more nuanced. Sometimes, a program must skip over certain statements, run a set of statements repetitively, or pick between other sets of statements to execute. This is called "conditional branching."
That's when control structures come into play, which controls the sequence in which statements in a program are executed.
The if statement is the first control structure you'll encounter in Python.
Real-world situations frequently need us to examine the information around us and then make a decision based on what we've observed. As an illustration;
Unless it's raining, I'll be mowing the yard. It's correct to say that if it's pouring or snowing, I won't be mowing the lawn.
This type of decision-making is performed in Python programs using the if statement. If an expression has a certain value, and that value is known, a statement or set of statements can be executed.
Let`s get started.
We'll begin with the simplest form of an if statement. This is how it appears in its most basic form:
As you can see:
Execution of the statement occurs when the expression evaluates to a "truthy" value. No action takes place if expr is false. You must include a colon (:) after expr. Python does not require the parentheses around expr, as some other programming languages do.
This type of if statement is used in a variety of ways:
There is no effect on pressing Enter key after you have typed the print('yes') expression when using these examples interactively in a REPL session. There are multiple lines in this command. You must press Enter a second time to complete it. Executing a script file doesn't necessitate the use of an extra newline.
Suppose, on the other hand, that you wish to assess a condition and then take many actions if it is true:
There is only one 'statement' in each of the cases above, as demonstrated. It's necessary to be able to express "Do this if [expr] is true."
Syntactic devices, which bring together several statements into a single compound statement or block, are the most common technique employed by most programming languages. Syntactically, a block is considered to be a single entity. Explanation: All statements in the block are performed when it is an "if" target and "expr" is true. None of them are true if expr is false.
It is possible to define blocks in virtually all programming languages, however, this is not always possible. Let's have a look at Python's approach.
You may have heard the offside rule in football, right? Well, in programming, the off-side rule is a tenet of the Python programming language. Indentation is used by rule-abiding languages to define blocks. Off-side rule adherent Python is one of few languages.
Indentation has a specific meaning in a Python program, as you learned in the last tutorial on the structure of Python programs. The reason for this is that indentation is used to denote blocks of related statements. A block in a Python program consists of a series of statements that are all indented the same way. Thus, a Python compound if statement looks like this:
Lines 2 to 5 are considered to be part of the same block because they all have the same indentation level. If expr is true, the entire block executes, while if expr is false, the block is skipped. Following the following statement> (line 6) execution continues.
Tokens are not used to indicate the end of a block. There are two ways to tell when a block has come to a close.
Take foo.py as an example:
This is what happens when you run foo.py:
Lines 2-5 have the same indentation and print () commands. As a result, they form the code that would be executed if the underlying assumption was correct. Because it is untrue, the entire block is ignored. It doesn't matter whether or not lines 2 to 5 are executed, the first statement with a lower indentation level, the print () statement on line 6, is executed.
There is no limit on how deep blocks can be nested. Each new block is defined by a new indent, and each previous block is ended by an outdent. In the end, the structure is simple to follow, consistent, and easy to understand.
This script, called blocks.py, is a bit more complicated.
The following is an example of what you'll see after running this script:
When entering multiline expressions into a REPL session, you must include an extra newline because of the off-side constraint. Otherwise, the translator would have no means of knowing the if block's final statement had been entered.
Perhaps you'd like to know what other options are out there. It's unclear how blocks are declared in languages that don't follow the off-side rule
To denote the beginning and end of a block in most programming languages, special tokens are used as a strategy. Curly braces () are used to define blocks in Perl, for example:
Other programming languages, such as C/C++ and Java, also make use of curly brackets in this fashion.
Algol and Pascal, on the other hand, employ the keywords begin and end to denote the beginning and finish of a block.
It's all about how you look at it. They tend to have a strong opinion about how they do things in general. The off-side rule can generate a lot of controversies when it comes up for discussion.
The off-side rule is an issue you'll have to deal with if you are writing Python code. Python's control structures all rely on it, and you'll see this in several upcoming lectures. Many programmers initially resisted Python's approach to defining blocks, but they've since learned to enjoy it and even prefer it over more traditional methods.
If a certain condition is met, you may wish to conduct a certain course of action, but if it isn't, you may want to specify another course of action. The else clause is used to accomplish this:
If expr> is true, the first suite is run and the second is skipped. Second Suite Execution Is Skipped If 'Expr' Is False Execution resumes after the second suite is completed. Indentation is used to distinguish between the two suites, as indicated in the preceding paragraph. For example, lines 4 to 5 are run, and lines 7 to 8 are omitted because x is less than 50:
Because x exceeds 50 in this case, the first suite is omitted in favor of the second, which is run.
It's also possible to branch execution based on a variety of possible outcomes. One or more elif clauses can be used to do this. Each expr is evaluated in turn by Python, which then executes the set of instructions associated with the first one that is found to be true.
You can provide as many elif clauses as you like. The else clause is not required. One must be provided at the end if it is present:
An if statement with elif clauses, like the ‘and’ and ‘or’ operators, uses short-circuit evaluation. The remaining expressions are not tested when one of the tests returns true and its block is run. This can be seen in the following example:
There is a zero division in the second equation, and an undefined variable var is referred to in the third. As long as the first criterion is met, neither option will be assessed.
The following is a standard way to write if (expr) indented on a separate line from the statement (statement):
However, an entire if statement can be written on a single line. The following is essentially the same as the previous example. Semicolons are used to separate multiple statements on the same line.
One exception to this rule is when an entire if statement is written in one line. Functionally, this is just like the example above. Separated by semicolons, you can have multiple statements on a single line.
Unlike the other if statement forms, this one does not control the flow of program execution, unlike the ones listed above. It's more like an expression-defining operator. Conditional expr> is first evaluated in the above example. The expression evaluates to expr1 if it is true. It returns a value of expr2 if it is false.
It's important to note that the evaluation of the middle expression comes before the evaluation of the two ends, and as a result, only one of the two ends is returned. Here are a few real-world examples to illustrate my point:
Selective assignment of variables is a popular application of the conditional statement. Let's say you're trying to figure out which of two numbers is greater. You could, of course, use the built-in method max() to accomplish the same thing. But what if you want to start from scratch and develop your code?
The term "code stub" refers to a placeholder for a section of code that hasn't yet been implemented, such as when writing a test case.
Token delimiters, such as the curly brackets in C or Perl, can be used to define a code stub in these languages. Perl or C code like the following is acceptable:
The curly braces here denote an empty area. Even if the expression x is true, Perl or C will do nothing after evaluating it.
Specifying an empty block is impossible because Python utilizes indentation rather than delimiters. A follow-up statement, either indented or on the same line, is required after an if statement that begins with if expr. Consider foo.py as an example:
Foo.py doesn't work if it is attempted to be run.
This issue can be solved with the Python pass command. It does not affect the program's behavior. With this placeholder, the interpreter is kept happy in situations where a statement is required syntactically but no action is desired:
Foo.py is now error-free:
Congratulations! You have completed this tutorial on conditional statements in Python. We've explored the if-else statement in Python code and learned how to organize statements into blocks and understand the control structure concept in Python. Developing more complicated Python programs relies heavily on understanding these ideas. The while statement and the for statement are two new control structures that will be introduced in the next tutorial.
Welcome to the fourteenth chapter of our python tutorial course. In the last lesson, we looked at sets and operations done to sets, including union and intersection. In this tutorial, we'll take a closer look at lists and tuples to see how they're used. Python's most versatile and useful data types are lists and tuples. A non-trivial Python application will nearly always have these.
Lists and tuples have a number of significant features that you'll learn about. In this course, you'll understand the definitions and applications of these terms. By the time you're done, you'll know when and how to employ different Python object kinds.
In other words, Lists are similar to arrays in many other programming languages because they allow you to store any number of arbitrary elements within them. For a list to exist in Python, an object sequence must be enclosed in square brackets ([]) as seen in the example below:
In other words, a list is more than a collection of things. Collections of things are organized in this way. Lists are defined by the order in which their elements are listed, and this order is maintained throughout the life of the list itself. For more information on Python data types, check the dictionaries tutorial (coming soon).
A comparison of two lists that contain the same contents but are organized differently is impossible:
A list can be made up of any number of items. A list can have all of its elements of the same type:
Different kinds of elements can be used.
Complex objects such as functions, classes, and modules can also reside in lists, as you'll see in forthcoming tutorials:
From 0 to the limit of your computer's RAM, a list can contain any number of items.
Uniqueness isn't required for list objects. There is no limit to the number of times an object can be listed:
This is a question you could ask yourself whenever you need to access items in a list, and the answer is yes: an index in square brackets can be used to access items in a list. In other words, it's the same as looking up individual characters in a string. As with strings, the indexing of lists is zero-based. The following is a sample list:
Here are the indices for the items in a:
Slicing is another option. For lists, the formula a[m:n] retrieves only the part of a that is between m and but not containing n in the list a.
As you learned before, an item in a list can be of any type. Another list is included in that. You can have as many sublists as you want within a single list.
As an illustration, consider the following (obviously fabricated) scenario:
x refers to an item structure depicted in the image below:
These three strings below, are all one character in length:
Example of sublists are shown below:
Simply add an additional index to have access to the items in a sublist:
To the degree that your computer's RAM allows, there is no limit to the depth or complexity of nested lists in this manner.
A lot of your experience so far has been with atomic data types. Primitive units, such as integers and floats, are those that cannot be decomposed further. Once they've been allocated, these types aren't able to be modified. Changing the value of an integer doesn't make sense at all. If you prefer a different integer, simply change the one you've assigned.
The string type, on the other hand, is a complex type. Strings can be broken down into their constituent characters. Think of a string of characters and how they might be rearranged. However, this is not possible. Strings are also immutable in Python.
This is the first time you've met a mutable data type, the list. It is possible to add or remove items from a list at any time after it has been created. Lists can be modified in a variety of ways in Python.
A single value can be replaced in a list using indexing and simple assignment.
A string can't be used to accomplish this, as demonstrated in the Python tutorial Strings and Character Data.
In order to remove a list item, use the del command:
Suppose you'd like to change several neighboring items in a list at the same time. The following Python syntax for a slice assignment makes this possible.
Consider an iterable list at this point. iterable is substituted for the slice of a specified here:
It's not necessary to have the same number of new elements as the number of old ones. Python simply increases or decreases the list based on the task at hand. Utilize a slice which only refers to one element when you wish to replace a single element with multiple ones:
You can also add items to a list without having to remove anything from the original list. Simply type [n:n] to produce a zero-length slice at the requested index.
You can remove a large number of items from a list by assigning the correct slice to an empty list. It is possible to use the del statement with the same slice:
To add more items to the beginning or end of a list, you can use the + concatenation operator or the += augmented assignment operator:
For example, a singleton list can only have one item in it, hence, it must be added to a different list:
Python provides a number of built-in methods for modifying lists. Below, you'll find more information on these methods. The target string was not directly modified in the previous tutorial's string methods. Strings are immutable, so this is why. String methods, on the other hand, give you back a completely rewritten string object. They don't change the target string at all:
List methods differ from other approaches. Lists are changeable, therefore the target list gets modified while the list method is running.
Adds a new item to the end of a collection.
List functions change the target list on the fly. They don't give you a new one:
Adds items from an iterable to a list.
Yes, it's most likely what you're expecting. Additionally, an iterable is required as an argument to extend(). iterable> elements are inserted one at a time:
To put it another way, extend() functions similarly to the plus sign (+). Because it alters the list while it's still in place, it's equivalent to the += operator:
A new element is added to a collection with the help of this method. Object obj> is inserted into the list an at the index indicated by insert(index>, obj>). It's a[index>] obj, and the remaining list items are moved rightward after the function call.
In a list, this function removes one item. remove(<obj>) list an is cleared of obj. An exception is thrown if obj> is not in a:
In a list, this function removes one item. There are two key differences between this method and remove():
The last item in the list is simply removed by calling pop():
Specifying an index in the optional index parameter causes this command to remove and return the given item. Like string and list indexing, index can be negative.
Python lists are described in this course by a set of six qualities. Finally, lists can be reordered. Sections above have shown many instances of this. A list expands as new things are added:
Similarly, as things are removed from a list, the list gets smaller.
A tuple is a collection of things that are arranged in a specific order. When it comes to the pronunciation of a word or phrase, it depends on who you ask. A few people say it as if it were spelled "too-ple," while others pronounce it as "tup-ple," which rhymes with "supple." Because everyone I know pronounces "supple," "quintuple," "sextuple," and "octuple" as though they rhyme with "supple," my preference is for the latter.
Lists and tuples are nearly identical, with the exception of the following characteristics:
As an illustration of tuples in action, consider the following code sample:
There's no need to worry! Reversing a tuple is as simple as using our usual string and list reversal process:
It's important to remember that although though tuples are constructed using parenthesis, you still use square brackets to index and slice them.
A tuple is a list with the same properties as a list: it's ordered, it can include arbitrary objects; it's indexable and sliceable; and it can be nestable like any other list. However, they cannot be changed:
There is a way to display the values of several objects at once in a Python REPL session by simply inserting them one after the other between commas:
Because Python interprets the input as a tuple, it presents the response in parentheses. The definition of a tuple has a peculiarity that you should know about. It's impossible to be vague when creating a tuple that has no items or a tuple with two or more. A tuple is defined in Python:
Because parentheses are used to denote operator precedence in expressions, the expression (2) creates an int object. Before closing parentheses, you need to put in an extra comma (,): This tells Python that you plan to create a single tuple.
There has to be a mechanism to define a singleton tuple, even if you don't need to do it very often.
Using Python, you can display a singleton tuple by putting a comma in front of it:
You've seen this before: a literal tuple can be allocated to a single object.
When this happens, it's as if the tuple's contents have been "stuffed" into the object:
"packed" objects can be "unpacked" into a new tuple by assigning them to the new tuple's objects.
Otherwise, a problem will emerge when unpacking a tuple: if there are more variables than values, an error will occur.
Compound assignments can be created by combining the steps of packing and unpacking into a single expression.
It's important to remember that in this tuple, the components on the left and right must be equal.
It is possible to leave off the parentheses required to denote a tuple in Python assignments like this one and a few others:
If you're unsure whether or not the parentheses are necessary, go ahead and put them in if you have any doubt. Python idioms are made possible by multiple assignment. As a programmer, it is common to have two variables whose values must be swapped. While the swap is taking place, a temporary variable must be used to store one of the values.
In Python, a simple tuple assignment is all that is needed to perform a swap:
If you have ever used a Python temporary variable to exchange values, this is the pinnacle of modern technology. It's the greatest it's ever going to be.
Congratulations! You have now completed the list and tuple tutorial. Python lists and tuples were introduced, along with some of their basic features and operations. In Python, you'll be relying on these all the time. It is a list's primary property that it is organized. It is impossible to modify the order of a list's elements, unless, of course, the list is altered. The same is true for tuples, except that they can't be updated. Python's conditional statements will be covered in the upcoming lesson.
Hello readers, I hope you all are doing great. In this tutorial, we will learn how to access Firebase (a real-time database) to store and read values or data with ESP32.
It is Google’s mobile application development platform that can be used to can access, monitor and control ESP32 from anywhere in the world with its (firebase) real-time database.
| Where To Buy? | ||||
|---|---|---|---|---|
| No. | Components | Distributor | Link To Buy | |
| 1 | ESP32 | Amazon | Buy Now | |
Firebase real-time database is a development platform provided by Google which included multiple services to manage and authenticate data.
Firebase is basically a mobile and web app development platform I as works great with Android APIs) that includes features like firebase cloud, real-time data and Firebase authentication etc.
As per Firebase’s official documentation (https://firebase.google.com/docs/database), whenever a user creates a cross-platform application like with Android, or Apple, JavaScript SDKs, all the clients share a single.
Fig. 1 Firebase Real-time database and ESP32
The main features of the Firebase Real-time database are:
The IoT or Internet of Things is the interconnection of physical objects or devices with sensors and software accessing capabilities to communicate data or information over the internet.
To build an IoT network, we need an interface medium that can fetch, control, and communicate data between sender and receiver electronics devices or servers.
Firebase real-time database provides a platform to store data collected from sensors at the level device. Firebase works great with Android APIs.
Firebase is particularly useful in data-intensive Internet of things (IoT) applications to store from sensors and synch that data between users in real-time. For simplicity or better understanding we can say that it is a cloud service provided by Google for real-time collaborative apps.
The steps involved in creating a Firebase project are:
Fig. 2 Get started
Fig. 3 Create a project
Fig. 4 project name
Fig. 5 Enabling Google Analytics
Fig. 6 Project Created successfully
As per the official firebase documentation at: https://firebase.google.com/docs/auth , the identity of a user is required by most online services or mobile applications or we can say , it handles authentication process and logging in (in this tutorial, the ESP32). Getting to know the identity of a user enables an application to save user data securely in the cloud and provide a consistent personalized service across all of the customer's devices (android phones, computers, applications etc).
Fig. 7 Authentication
Fig. 8 Select authentication method
Next thing is creating a real-time database for the project.
Fig. 9 Real-time database
Fig. 10 Creating database
Fig. 11
Fig. 12 select location
Fig. 13 Accessing project API key
We are using Arduino IDE to compile and upload code into the ESP32 module. You must have the ESP32 board manager installed on your Arduino IDE to program the ESP32 module. To know more about Arduino IDE and how to use it, follow our previous tutorial i.e., on ESP32 programming series. The link is given below:
https://www.theengineeringprojects.com/2021/11/introduction-to-esp32-programming-series.html
Steps to add the necessary libraries in Arduino IDE:
Fig. 14 manage libraries
Fig. 15 Install Firebase ESP Client Library
//--add necessary header files
#include <WiFi.h>
#include <Firebase_ESP_Client.h>
#include "addons/TokenHelper.h" //Provide the token generation process info.
#include "addons/RTDBHelper.h" //Provide the real-time database payload printing info and other helper functions.
// Insert your network credentials
#define WIFI_SSID "replace this with your netwrok SSID"
#define WIFI_PASSWORD "replace this with your wi-fi password"
// Insert Firebase project API Key
#define API_KEY "replace this with your API key"
// ----Insert real-time database URL
#define DATABASE_URL "replace this with your project URL"
//----Define Firebase Data object
FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;
int value = 10;
bool signupSuccess = false;
unsigned long sendDataPrevMillis = 0;
void setup()
{
Serial.begin(115200);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
Serial.print("Connecting to Wi-Fi");
while (WiFi.status() != WL_CONNECTED){
Serial.print(".");
delay(100);
}
Serial.println();
Serial.print("Connected with IP: ");
Serial.println(WiFi.localIP() );
Serial.println();
// Assign the api key ( required)
config.api_key = API_KEY;
// Assign the RTDB URL ( required)
config.database_url = DATABASE_URL;
// Sign up status
if (Firebase.signUp(&config, &auth, "", ""))
{
Serial.println("ok");
signupSuccess = true;
}
else{
Serial.printf("%s\n", config.signer.signupError.message.c_str());
}
/* Assign the callback function for the long running token generation task */
config.token_status_callback = tokenStatusCallback; // see addons/TokenHelper.h
Firebase.begin(&config, & auth);
Firebase.reconnectWiFi( true);
}
void loop()
{
if (Firebase.ready() && signupSuccess && (millis() - sendDataPrevMillis >
10000 || sendDataPrevMillis == 0))
{
sendDataPrevMillis = millis();
if (Firebase.RTDB.setInt(&fbdo, "test/int", value))
{
Serial.println("PASSED");
Serial.println("PATH: " + fbdo.dataPath());
Serial.println("TYPE: " + fbdo.dataType());
}
else
{
Serial.println("FAILED");
Serial.println("REASON: " + fbdo.errorReason());
}
value++;
}
}
Before uploading the code in ESP32 board there are some changes you need to make which includes:
Fig. 16 Header files
Fig. 17 Helper libraries
Fig. 18 Insert API key
Fig. 19 RTDB URL
Fig. 20 Firebase Data Objects
Fig. 21 Enter Network credentials
Fig. 22 variable declaration
Fig. 23 Initialize wifi module
Fig. 24 Fetch/obtain the IP address
Fig. 25 configuring API key
Fig. 26 configuring database URL
Fig. 27 sign up status
Fig. 28
Fig. 29 Loop() function
Fig. 30 Select development board and COM port
Fig. 31 Result 1
Fig. 32 Result 2
This concludes the tutorial. I hope you found this of some help and also hope to see you soon with a new tutorial on ESP32.
Hello readers, I hope you all are doing great. In this tutorial, we will learn how to interface the BMP280 sensor with the ES32 module to get temperature, pressure and altitude readings. Later, in this tutorial, we will also discuss how to upload these sensor readings to a web server.
| Where To Buy? | ||||
|---|---|---|---|---|
| No. | Components | Distributor | Link To Buy | |
| 1 | ESP32 | Amazon | Buy Now | |
BMP280 or Barometric pressure sensor is a module used to measure temperature pressure and altitude. The small size and low power consumption feature of this sensor makes it feasible for battery-powered devices, GPS modules and mobile applications etc.
Fig. 1 BMP280 Sensor
The BMP280 is the product of BOSCH which is based on Bosch’s proven Piezo-resistive pressure sensor technology featured with high accuracy, long term stability, linearity and high EMC robustness.
BMP280 is the successor of the BMP180 sensor and offers high performance in all the areas that require precise temperature and pressure measurements.
Emerging applications like fitness, indoor navigation, GPS refinement requires relative accuracy and BMP280 is perfect for such applications. Very low TCO (Temperature coefficient of Offset ) makes this module preferable over other available modules for temperature measurements.
We can also use a DHT11/DHT22 sensor for temperature and humidity measurements but the BMP280 sensor provides better accuracy (i.e., 0.01°C) than DHT sensors.
There are two methods of interfacing BMP280 sensor with ESP32 module:
In the bMP280 Sensor module, there are six interfacing pins including VCC and GND.
Fig. Interfacing BMP280 and ESP32
We are using the I2C protocol for interfacing the two (ESP and BMP280) so only SCL and SDA pins will be used with power pins for interfacing. The SDO and CSB pins will be used only if you are using the SPI protocol for interfacing.
Table 1
We are using Arduino IDE to compile and upload code into the ESP32 module. You must have ESP32 board manager installed on your Arduino IDE to program the ESP32 module. To know more about Arduino IDE and how to use it, follow our previous tutorial i.e., on ESP32 programming series. The link is given below:
https://www.theengineeringprojects.com/2021/11/introduction-to-esp32-programming-series.html
Steps to add the necessary libraries in Arduino IDE:
Fig. 2 manage libraries
Fig. 3 Install library
#include <Wire.h>
void setup()
{
Wire.begin();
Serial.begin(115200);
Serial.println("\nI2C Scanner");
}
void loop()
{
byte error, address;
int nDevices;
Serial.println("Scanning...");
nDevices = 0;
for(address = 1; address < 127; address++ )
{
Wire.beginTransmission(address);
error = Wire.endTransmission();
if (error == 0)
{
Serial.print("I2C device found at address 0x");
if (address<16)
{
Serial.print("0");
}
Serial.println(address,HEX);
nDevices++;
}
else if (error==4)
{
Serial.print("Unknow error at address 0x");
if (address<16) {
Serial.print("0");
}
Serial.println(address,HEX);
}
}
if (nDevices == 0) {
Serial.println("No I2C devices found\n");
}
else {
Serial.println("done\n");
}
delay(5000);
}
#include <Wire.h>
#include <Adafruit_BMP280.h>
#define BMP_SDA 21
#define BMP_SCL 22
Adafruit_BMP280 bmp280;
void setup()
{
Serial.begin(115200);
Serial.println("Initializing BMP280");
boolean status = bmp280.begin(0x76);
if (!status)
{
Serial.println("Not connected");
}
}
void loop()
{
float temp = bmp280.readTemperature();
Serial.print("temperature: ");
Serial.print(temp);
Serial.println("*C");
float altitude = bmp280.readAltitude(1011.18);
Serial.print("Altitude: ");
Serial.print(altitude);
Serial.println("m");
float pressure = (bmp280.readPressure()/100);
Serial.print("Pressure: ");
Serial.print(pressure);
Serial.println("hPa");
Serial.println(" ");
delay(1000);
}
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10 Select development board and COM port
Fig. 11 Serial monitor output
Most of the industries and organizations these days are shifting to the efficient ways of operating things and the IoT internet of things is one of them.
Internet of Things is a system of multiple inter-related computing devices. The factor ‘thing’ in IoT is designated to an entity capable of communicating data over a network (IOT), which can be a digital machine, sensor, human being, animals etc.
Each component that is included in IoT network is assigned with an unique identity called UID and the ability to communicate data over IoT network without any external human or computer intervention.
Fig. 12 IoT
ThingSpeak is an open data platform for the Internet of Things applications. It is a MathWorks web service that allows users to send sensor readings and data to the cloud. We can also visualize and act on the data (calculate the data) that is sent to ThingSpeak by the devices. The information can be saved in both private and public channels.
ThingSpeak is frequently used for IoT prototyping and proof-of-concept devices that require data analysis.
Downloading and installing the required Library file:
https://github.com/mathworks/thingspeak-arduino
Fig. 13 Adding ThingSpeak library
To check whether the library is successfully added or not:
Fig. 14
Fig, 15 Arduino IDE Library manager
Fig. 16 Getting started for free
Fig. 17 Create new account
Fig. 18 MathWorks Sign in
Fig. 19 New Channel
Fig. 20 Creating channel and respective fields
Fig. 21 save the channel
Fig. 22 Field Chart Edit
// ------style guard ----
#ifdef __cplusplus
extern "C"
{
#endif
uint8_t temprature_sens_read();
#ifdef __cplusplus
}
#endif
uint8_t temprature_sens_read();
// ------header files----
#include <WiFi.h>
#include "ThingSpeak.h"
#include <Wire.h>
#include <Adafruit_BMP280.h>
#define BMP_SDA 21
#define BMP_SCL 22
Adafruit_BMP280 bmp280;
// -----netwrok credentials
const char* ssid = "public"; // your network SSID (name)
const char* password = "ESP32@123"; // your network password
WiFiClient client;
// -----ThingSpeak channel details
unsigned long myChannelNumber = 4;
const char * myWriteAPIKey = "9R3JZEVBG73YE8BY";
// ----- Timer variables
unsigned long lastTime = 0;
unsigned long timerDelay = 1000;
void setup()
{
Serial.begin(115200); // Initialize serial
Serial.println("Initializing BMP280");
boolean status = bmp280.begin(0x76);
if (!status)
{
Serial.println("Not connected");
}
//Initialize Wi-Fi
WiFi.begin(ssid, password);
Serial.print("Connecting to Wi-Fi");
while (WiFi.status() != WL_CONNECTED)
{
Serial.print(".");
delay(100);
}
Serial.println();
Serial.print("Connected with IP: ");
Serial.println(WiFi.localIP());
Serial.println();
// Initialize ThingSpeak
ThingSpeak.begin(client);
}
void loop()
{
if ((millis() - lastTime) > timerDelay )
{
float temp = bmp280.readTemperature(); //temperature measurement
Serial.print("temperature: ");
Serial.print(temp);
Serial.println("*C");
float altitude = bmp280.readAltitude(1011.18); //altitude measurement
Serial.print("Altitude: ");
Serial.print(altitude);
Serial.println("m");
float pressure = (bmp280.readPressure()/100); //pressure measurement
Serial.print("Pressure: ");
Serial.print(pressure);
Serial.println("hPa");
Serial.println(" ");
ThingSpeak.setField(1, temp );
ThingSpeak.setField(2, altitude);
ThingSpeak.setField(3, pressure);
// Write to ThingSpeak. There are up to 8 fields in a channel, allowing you to store up to 8 different
// pieces of information in a channel. Here, we write to field 1.
int x = ThingSpeak.writeFields(myChannelNumber,
myWriteAPIKey );
if(x == 200)
{
Serial.println("Channel update successful." );
}
else
{
Serial.println("Problem updating channel. HTTP error code " + String(x) );
}
lastTime = millis();
}
}
We are describing only the ThingSpeak server part as the BMP280 and ESP32 interfacing part has already been discussed in the above code description.
Fig. 23 Style guard
Fig. 24 Libraries
Fig. 25
Fig. 26
Fig. 27
Fig. 28
Fig. 29
Fig. 30
Fig. 31
Fig. 32 Sensor readings
Fig. 33 setting respective Fields
Fig. 34
Fig. 35
Fig. 36 ThingSpeak server
Fig. 37 Sensor readings on the Serial monitor
This concludes the tutorial. I hope you found this of some help and also hope to see you soon with a new tutorial on ESP32.
In PCB boards you come across LEDs fixed in them, and due to the evolving world of technology, things are changing so first leading to the crafting of new technologies that have led to changes in the LED areas. The LED case is an area that has involved the combination of two methods of technologies in order to come up with something else that is more efficient when it comes to solving the intended purpose. This LED PCB comes with advantages of longevity and durability.
This is a type of PCB that is used for the purpose of lighting in the lighting appliances like modern LED bulbs. The material used in the process of making this board currently is the metal copper clad that has a very good heat-dissipating function. In general, we should note that the single layer LED PCB is made up of three layers namely the circuit layer, the ceramic layer and the insulation layer.
This is made up of the electrolytic copper foil and is etched to form the printed circuit board where the components are attached. When you do the comparison with the traditional boards, the LED board can carry a larger amount of current.
This layer is the core technology behind this type of boards and plays greater roles in the conduction insulation and bonding of the layers.
Here aluminum is the best choice compared to its availability and the cheap prices it offers. Stainless steel, silicon and the iron can be used if the thermal conductivity required is very high.
This consist of the substrate layer together with a conductive layer. A solder mask together with a silkscreen offer protection functions to these layers.
When you don a comparison with the single layer PCBs, you will realize that this has two copper layers which apparently makes them heavier as the number of conductive layers also increase to two.
There are two assembly methods that can be employed in the assembly if the LED PCBs. These methods are used to attach components on the board and we shall discuss it below;
This method involves mounting the electronic components directly into the board copper layer.
This method involves the drilling of holes into the PCB boards where components are then mounted to the holes using the long leads that are then soldered and the whole filled with flux.
This is one of the common applications the LED PCBs where they find great use on the consumer lighting from flash lights, lamps, spotlights, lanterns to solar powered lighting applications.
LED are also becoming a common application in the electronic devices such as the computer keyboards backlights. Other devices that have employed this technology are smartphones, tablets and the televisions.
Telecommunication displays and indicators use the LED PCBS because of their durability the ability to transfer heat and their longevity since telecommunication gadgets generate a lot of heat.
LEDs have a lot of use in the traffic and the transportation industry ranging from the stop lights and the automotive themselves. In the car this PCs are found in the headlights, fog lights, brake lights, reverse lights and the indicators. Highways tunnel lighting also use this technology. The modern streetlighting system is done using the LED PCBs.
Medical lighting and the medical equipment lighting that are used for medical examination and surgery often use this type LED PCBs.
