Project Files of Raspberry Pi 3 Model A+ Library for Proteus: WiFi Web Page, MAX7219

RASPBERRY PI 3 MODEL A+ LIBRARY FOR PROTEUS - V1.0 (BCM2837B0 1.4 GHZ, 512 MB, DUAL-BAND WI-FI, 40-PIN HEADER, 1 USB)
YOUR PYTHON PROGRAM RUNS ON THE BOARD - DEMO: A WI-FI MESSAGE BOARD (MAX7219 MATRIX, 28BYJ-48 STEPPER, A WEB PAGE)
Designed by The Engineering Projects www.TheEngineeringProjects.com

IMPORTANT LINKS
Article (read it first - pictures, step by step, every feature explained):
  https://www.theengineeringprojects.com/2026/10/raspberry-pi-3-model-a-plus-library-for-proteus.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/raspberry-pi-3-model-a-plus-proteus-library
The demo's parts are our libraries (included) - their articles:
  MAX7219:  https://www.theengineeringprojects.com/2026/10/max7219-led-matrix-library-for-proteus-v1-0.html
  Stepper:  https://www.theengineeringprojects.com/2026/10/28byj-48-uln2003-stepper-motor-library-for-proteus-v1-0.html
  Laptop:   https://www.theengineeringprojects.com/2026/10/laptop-wifi-monitor-library-for-proteus.html
  Phone:    https://www.theengineeringprojects.com/2026/10/mobile-wifi-monitor-library-for-proteus.html
The earlier boards of this series:
  https://www.theengineeringprojects.com/2026/10/raspberry-pi-model-b-library-for-proteus.html
  https://www.theengineeringprojects.com/2026/10/raspberry-pi-1-model-b-plus-library-for-proteus.html
  https://www.theengineeringprojects.com/2026/10/raspberry-pi-2-model-b-library-for-proteus.html
  https://www.theengineeringprojects.com/2026/10/raspberry-pi-3-model-b-library-for-proteus.html
  https://www.theengineeringprojects.com/2026/10/raspberry-pi-3-model-b-plus-library-for-proteus.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
Raspberry-Pi-3-Model-A-Plus-TEP-v1.0/
|-- Proteus Library Files/
|   |-- TEPLAPTOP.LIB                                    39.5 KB   the laptop (demo), to LIBRARY
|   |-- TEPMAX7219.LIB                                  242.3 KB   the MAX7219 matrix (demo), to LIBRARY
|   |-- TEPMOBILE.LIB                                    13.1 KB   the phone (demo), to LIBRARY
|   |-- TEPRPI3AP.LIB                                    56.1 KB   the Raspberry Pi 3 Model A+, to LIBRARY
|   |-- TEPULN2003.LIB                                   89.7 KB   the ULN2003 + 28BYJ-48 (demo), to LIBRARY
|-- Proteus Model Files/
|   |-- TEPMAX7219.DLL                                  294.0 KB   the MAX7219 matrix, to MODELS
|   |-- TEPNET.DLL                                       2.37 MB   the Pi + monitors + network, to MODELS
|   |-- TEPULN2003.DLL                                  308.0 KB   the ULN2003 + 28BYJ-48, to MODELS
|   |-- TEPPi/python/                                   17.54 MB   Python 3.11.9 embeddable (33 files)
|   |-- TEPPi/runtime/                                  856.3 KB   TEP Pi runtime, gpiozero (61 files)
|-- Python Code/
|   |-- blink.py                                          0.3 KB   an LED on GPIO17 (the default)
|   |-- message_board.py                                  9.3 KB   the demo
|-- Proteus Simulation/
|   |-- message_board.py                                  9.3 KB   the program of the demo
|   |-- Pi-3-Model-A-Plus-WiFi-Message-Board.pdsprj      36.6 KB   the demo: Wi-Fi message board
|   |-- TEPMAX7219.DLL                                  294.0 KB   copy of the model
|   |-- TEPNET.DLL                                       2.37 MB   copy of the model
|   |-- TEPULN2003.DLL                                  308.0 KB   copy of the model
|-- README.txt                                          ~18.0 KB   this file
Total: 24.80 MB (unzipped). The source code of the models and of the TEP Pi runtime is not included.

WHAT IS IT?
The Raspberry Pi 3 Model A+ (2018) as one Proteus part - and a way to run Raspberry Pi programs in Proteus 8.5.
Proteus cannot run Raspberry Pi OS, so this library does not emulate Linux. It does what matters for electronics: the
board runs YOUR PYTHON PROGRAM (a .py file, the PROGRAM property) against the circuit on the sheet, with the Python
libraries a Pi uses for its pins, its I2C / SPI / UART buses and its Wi-Fi.
  * At Run the board starts Python 3.11 (included: the TEPPi folder) with our TEP Pi runtime, then your program.
    The program and Proteus work in lockstep: while the program runs, Proteus waits; while the program sleeps, waits
    for a pin, a bus or the network, Proteus runs. So time.sleep(0.5) is 0.5 s of simulation, a busy loop still moves
    the clock (about 2.6 us per GPIO call, as Python on the A+'s 1.4 GHz Cortex-A53), and every edge is on time.
    time.time(), time.monotonic(), time.strftime() and datetime.now() follow the simulation's clock too.
  * Wi-Fi only (the A+ has no Ethernet): wlan0 joins the network in the WIFISSID / WIFIPASS properties (default: our
    router "TEP-WiFi", password 12345678 - the network of our ESP32 / Arduino Wi-Fi parts and the Laptop / Mobile WiFi
    Monitors) as Raspberry Pi OS does at boot: 2.3 to 3.5 s after Run the Pi has 192.168.1.51 (192.168.1.(50 + the
    part's number)), the name raspberrypi.local. Sockets, http.server and urllib work on it.
  * Threads work (gpiozero's threads, your own threading.Thread, Timer, Queue, Lock): every wait is in simulation time;
    an error in a thread is printed as Python prints it ("Exception in thread ...").
  * The Python libraries for the pins (the same names, numbers and messages as on a Pi):
      RPi.GPIO      setmode, setup and output with one pin or a list (and a list of values), input, cleanup,
                    add_event_detect / event_detected / wait_for_edge with callbacks and bouncetime, PWM (software PWM
                    made by the board, steady while the program sleeps)
      gpiozero      LED, PWMLED, Button, OutputDevice, Buzzer, Servo, AngularServo, MotionSensor, DistanceSensor,
                    CPUTemperature and the rest (gpiozero 2.0.1, unchanged, on RPi.GPIO)
      spidev        SPI0 on GPIO11 (SCLK), GPIO10 (MOSI), GPIO9 (MISO), CE0 = GPIO8, CE1 = GPIO7, modes 0 to 3, up to
                    8 MHz; xfer / xfer2 take up to 4096 bytes (spidev's bufsiz), writebytes2 any length
      smbus2 / smbus  I2C bus 1 on GPIO2 (SDA) / GPIO3 (SCL) at 100 kHz, the Pi's 1.8 k pull-ups: read_byte,
                    write_byte, the byte / block reads and writes, write_quick, i2c_rdwr with i2c_msg; a device that
                    does not answer gives OSError [Errno 121] Remote I/O error
      serial        pyserial on /dev/serial0 (on a Pi 3 A+ = /dev/ttyS0, the mini UART; /dev/ttyAMA0 is accepted too):
                    TXD GPIO14, RXD GPIO15, any baud rate, timeouts, back-to-back bytes
      1-Wire        the DS18B20's files under /sys/bus/w1/devices (w1-gpio on GPIO4), as the kernel makes them
      Adafruit_DHT, adafruit_dht + board   DHT11 / DHT22 on any GPIO
      socket        TCP and UDP on wlan0, http.server / socketserver, urllib.request, select
  * The Pi's own files: /proc/cpuinfo (Revision 9020e0, four ARMv8 processors), /proc/device-tree/model ("Raspberry Pi
    3 Model A Plus Rev 1.0"), the CPU temperature in /sys/class/thermal (gpiozero's CPUTemperature), /proc/loadavg,
    /proc/meminfo (512 MB).
  * The Pi Terminal (our TEP window, no Windows title bar): the shell prompt (pi@raspberrypi:~ $ python3 ...), the
    program's output (OUT) and errors (ERR, as Python prints them on a Pi), a line for input() (IN); its Board tab
    shows the GPIOs (BCM numbers), the LEDs, the supply pins and RESTART PROGRAM. Click the HDMI socket or the
    processor to open it.
  * The LEDs: PWR (red) and ACT (green: it flickers while the board boots and when the program prints) standing at the
    left edge above the micro-USB.
  * The header's supply pins power the modules wired to them, as on the bench: 5V, 3V3 and GND as logic levels (an
    analog VCC reading sees 5 V on either rail).
The board is drawn our way at its real size (65 x 56 mm, rounded corners, the four mounting holes of the B+ boards):
the 40-pin header along the top edge, the metal shield can of the dual-band Wi-Fi / Bluetooth module (the raspberry
pressed into its lid) under pin 1, the DSI display connector with the microSD card under it, the BCM2837B0 under its
silver heat spreader with its crystal, the raspberry logo by the single USB-A socket on the right edge, the MaxLinear
MXL7704 power chip by the micro-USB, PWR / ACT at the left edge, HDMI, the CSI camera connector and the black 4-pole
A/V jack along the bottom (the 512 MB RAM is not drawn: it is not on the top). The 40 pins leave the top edge as one
comb 50 thou apart, each with a colour-coded tag: 5V red, 3V3 orange, GND black, GPIO green, I2C blue, SPI pink, UART
purple, ID_SD / ID_SC grey.

ONE DEVICE (search "RASPBERRY" in Pick Devices):
  RASPBERRY PI 3 MODEL A+  "Raspberry Pi 3 Model A+" V1.0 (category Microprocessor ICs > Raspberry Pi), prefix PI,
                           model TEPNET.DLL (with the TEPPi folder)
The same TEPNET.DLL also runs our Raspberry Pi Model B, 1 Model B+, 2 Model B, 3 Model B and 3 Model B+, our Ethernet
and Wi-Fi shields, modules and boards and the Laptop / Mobile WiFi Monitors; it replaces any older TEPNET.DLL (keep
only this newest one in MODELS).

TEST STATUS
V1.0: verified in Proteus 8.5 on 24 Oct 2026 with the demo project as shipped. What the Proteus runs showed:
* Pi-3-Model-A-Plus-WiFi-Message-Board: the matrix shows WI-FI, wlan0 joins TEP-WiFi and 2.5 s after Run the program
  prints "serving on http://192.168.1.51:8000/" and the matrix shows HELLO. The MAX7219's pop-up: 4 chips, FC16_HW,
  display on, intensity 4, 8 digits, no decode, SPI at 1.00 MHz, frames of 64 bits (one LOAD each).
* The laptop and the phone open http://192.168.1.51:8000/ (Browser, Go): the page shows the message, the turntable's
  angle, the brightness (4 of 15) and the CPU temperature, with the links - text links on the laptop, a grid of
  buttons on the phone.
* WELCOME on the phone: "the page: /msg/welcome" in the Pi Terminal and WELCOME TO TEP scrolls across the 32 columns.
  +180 on the phone: the ULN2003's pop-up shows RUNNING HALF STEP, 660 steps/s CW = 9.7 RPM at the shaft, about 81 mA;
  the 28BYJ-48's dial turns to 180 deg and the coils are switched off; 0 steps lost.
* OPEN on the laptop's page: the matrix shows OPEN; BRIGHTER twice on the phone: intensity 10 (21/32); TIME: the
  Pi's clock (HH:MM) on the matrix; HOME: the stepper turns back counter-clockwise to 0 turns, 0 steps lost.
* The Board tab: the BCM2837B0 at 1.4 GHz, GPIO8 (CE0) HIGH, GPIO10 / GPIO11 and the coils GPIO17 / 27 / 22 / 23 LOW at
  rest, 5V 5.00 V, 3V3 3.30 V, "No errors".
* Speed on our test PC: about 33 to 40 % of real time with the two pop-ups, the two monitors and the Pi Terminal open.

INSTALLATION (about 3 minutes)
1. Close Proteus. Extract the WHOLE ZIP to a normal folder (e.g. Desktop).
2. Copy everything in "Proteus Library Files" to the LIBRARY folder of Proteus, for example:
     C:\Program Files (x86)\Labcenter Electronics\Proteus 8 Professional\LIBRARY
   (on some PCs: C:\ProgramData\Labcenter Electronics\Proteus 8 Professional\LIBRARY - use the folder that already holds
   Proteus's own .LIB files). TEPRPI3AP.LIB is the Pi; TEPMAX7219.LIB, TEPULN2003.LIB (the driver and the motor),
   TEPLAPTOP.LIB and TEPMOBILE.LIB are the demo's parts.
3. Copy everything in "Proteus Model Files" - the DLLs AND the TEPPi folder - to the MODELS folder:
     C:\Program Files (x86)\Labcenter Electronics\Proteus 8 Professional\MODELS
   TEPPi holds Python 3.11 and the TEP Pi runtime; the Pi finds it next to TEPNET.DLL, in MODELS or next to your
   project. Replace an older TEPNET.DLL and TEPPi folder (these are the newest).
4. Delete TEPRPI3AP.IDX (and the .IDX of a part library you replaced) from the LIBRARY folder if it is there.
5. Start Proteus. In Pick Devices (P) search "RASPBERRY".
Nothing else to install: Python is in TEPPi (no Python on the PC needed, none is changed).

RUN THE DEMO
Keep the .py file and the DLLs beside the project in "Proteus Simulation" (the TEPPi folder in MODELS).
  Pi-3-Model-A-Plus-WiFi-Message-Board.pdsprj - PI1 runs message_board.py on Wi-Fi: MX1 = a 4-in-1 MAX7219 LED matrix
  (32 x 8, FC-16 wiring) on SPI0 (DIN on GPIO10 MOSI, CLK on GPIO11 SCLK, CS on GPIO8 CE0, VCC 5V), DRV1 = a ULN2003
  stepper driver board (IN1 - IN4 on GPIO17, 27, 22, 23, + on 5V) with M1 = a 28BYJ-48 stepper on its outputs (A - D
  orange, yellow, pink, blue; COM red); PC1 = the Laptop WiFi Monitor and MOB1 = the Mobile WiFi Monitor on the same
  network. The matrix and the driver are the Advance parts: their pop-up windows open at Run.
  Press Run: the matrix shows WI-FI while wlan0 joins "TEP-WiFi", the program starts http.server on port 8000 and the
  matrix shows HELLO. On the laptop or the phone open http://192.168.1.51:8000/ (Browser, the address, Go): the page
  shows what the board is doing - the message, the turntable's angle, the brightness, the CPU temperature - and its
  links set it: HELLO, WELCOME (a long text scrolls), OPEN, CLOSED, PI 3 A+ and TIME (the Pi's clock, HH:MM) on the
  matrix; -90, +90 and +180 deg and HOME for the stepper; DIMMER / BRIGHTER for the matrix's intensity (0 - 15). The
  phone shows the links as buttons. The stepper turns in half steps at about 10 RPM, with a ramp at the start and the
  end, and its coils are switched off when it stops. The program is pure Python - spidev for the MAX7219 with its own
  5 x 7 font, RPi.GPIO for the stepper's sequence, gpiozero's CPUTemperature, threads and http.server.

YOUR OWN PROGRAMS
Write the program with any editor, put the .py next to your project and set the Pi's PROGRAM property to its name (or
a full path). Start from Python Code\blink.py (an LED on GPIO17). Python's standard library is there; other
pure-Python packages work when you copy them next to your program. Use BCM numbers (GPIO.setmode(GPIO.BCM),
gpiozero's LED(17)) or GPIO.setmode(GPIO.BOARD) with the header's pin numbers.
A program that never sleeps and never touches a pin for 3 real seconds is left running on its own (the simulation
goes on); input() waits for a line typed in the Pi Terminal.

THE 40-PIN HEADER (BCM numbers - the tags on the board)
   1 3V3        2 5V          3 GPIO2 SDA    4 5V          5 GPIO3 SCL    6 GND         7 GPIO4 (1-Wire)
   8 GPIO14 TXD 9 GND        10 GPIO15 RXD  11 GPIO17     12 GPIO18      13 GPIO27     14 GND
  15 GPIO22    16 GPIO23     17 3V3         18 GPIO24     19 GPIO10 MOSI 20 GND        21 GPIO9 MISO
  22 GPIO25    23 GPIO11 SCLK 24 GPIO8 CE0  25 GND        26 GPIO7 CE1   27 ID_SD      28 ID_SC
  29 GPIO5     30 GND        31 GPIO6       32 GPIO12     33 GPIO13      34 GND        35 GPIO19
  36 GPIO16    37 GPIO26     38 GPIO20      39 GND        40 GPIO21
3.3 V logic: GPIO2 / GPIO3 have the Pi's 1.8 k pull-ups to 3.3 V; RPi.GPIO's pull-ups / pull-downs are weak drives.
ID_SD / ID_SC (27, 28, GPIO0 / GPIO1) are kept for a HAT's ID EEPROM; leave them free, as on a real Pi.

PROPERTIES (double-click the Pi > Edit Properties)
  PROGRAM    the Python program (default blink.py; a name next to the project or a full path)
  AUTOOPEN   the Pi Terminal at Run: YES (default) or NO
  WIFISSID   the Wi-Fi network wlan0 joins (default TEP-WiFi)
  WIFIPASS   its password (default 12345678)
  PYTHON     a python.exe of your own (empty: TEPPi's)
  RUNTIME    the TEP Pi runtime folder (empty: TEPPi's)

TROUBLESHOOTING
* "TEP Pi: the TEPPi folder ... was not found": copy the TEPPi folder from "Proteus Model Files" into MODELS (or next
  to the project).
* "python3: can't open file": the PROGRAM file is not next to the project - put it there or give a full path.
* ModuleNotFoundError for a package: only the libraries above are built in; copy a pure-Python package's folder next to
  your program.
* The program waits for Wi-Fi forever: check WIFISSID / WIFIPASS (the simulation log says "not found" or "wrong
  password").
* The page does not open: the address is http://192.168.1.51:8000/ (the port the program serves), and the program must
  have printed "serving on". A monitor sometimes needs Go a second time.
* The matrix shows the text mirrored or the modules in the wrong order: an FC-16 module takes its digit registers 1 - 8
  as the rows from the top, bit 7 = a module's leftmost column, and the first 16 bits of a frame reach the module
  furthest from DIN (the leftmost).
* The stepper hums or loses steps (the driver's pop-up counts lost steps): slow the step rate down or ramp it up and
  down, and keep the half-step order IN1, IN1+IN2, IN2, IN2+IN3, ...
* A paused simulation shows the SIMULATION LOG: click the Schematic Capture tab.

BUG REPORTS AND FEATURE REQUESTS
Please post them in our forum with a screenshot, the program, the Pi Terminal's text and the simulation log:
  https://www.theengineeringprojects.com/forum/category/raspberry-pi-3-model-a-plus-proteus-library

SUPPORT US
This library is free. If it saves you time, please support our work:
  https://www.theengineeringprojects.com/donate

WEBSITE
  https://www.theengineeringprojects.com/

LICENCES AND THIRD-PARTY NOTES
* The Raspberry Pi board model, the TEP Pi runtime, the Pi Terminal and the network (TEPNET.DLL, the compiled .pyc files
  in TEPPi\runtime with the stand-ins RPi, smbus2, smbus, spidev, serial, Adafruit_DHT, adafruit_dht, board), the
  symbols and artwork (TEPRPI3AP.LIB), the part models (TEPMAX7219 and TEPULN2003 .DLL / .LIB, the Laptop and Mobile
  WiFi Monitors' TEPLAPTOP.LIB / TEPMOBILE.LIB in TEPNET.DLL) and the demo program are made by The Engineering
  Projects. Our stand-ins follow the APIs of RPi.GPIO, smbus2, py-spidev, pyserial, Adafruit_DHT and
  adafruit-circuitpython-dht; none of their code is copied. The source code of the models is not included (nor the
  runtime's: it ships compiled for the included Python 3.11).
* TEPPi\python is the official embeddable Python 3.11.9 for Windows (32-bit) from python.org, unchanged, under the
  Python Software Foundation License (TEPPi\python\LICENSE.txt).
* TEPPi\runtime\gpiozero is gpiozero 2.0.1.post3 and TEPPi\runtime\colorzero is colorzero 2.0, unchanged, under the BSD
  3-Clause licence (their LICENSE files in the dist-info folders).
* Proteus is a product of Labcenter Electronics and is not included. Raspberry Pi is a trademark of Raspberry Pi Ltd.
  This library is not made or endorsed by Raspberry Pi Ltd or Labcenter.

MODEL SCOPE AND LIMITS
Modelled: the 26 GPIOs of the 40-pin header (inputs, outputs, RPi.GPIO's pull-ups / pull-downs, edges, software PWM),
the I2C, SPI, UART, 1-Wire and DHT buses as the Pi's drivers drive them, the supply pins, Wi-Fi (wlan0: the join, DHCP,
TCP and UDP to every TEP network part), the LEDs, a 0.5 s boot before the program starts, the Pi's /proc and /sys files
above, the Pi Terminal. Not modelled: Raspberry Pi OS (no desktop, no shell commands, no apt, no os.system), Bluetooth,
the 5 GHz band (the network is the same TEP network at any band), Wi-Fi scanning from the program, the four cores (one
program, its threads take turns), the HDMI and A/V outputs, the camera and display connectors, USB, the microSD card's
files, hardware PWM (GPIO18 is software PWM here), a HAT's ID EEPROM, C programs and C extensions, the real CPU's speed
(each GPIO call takes about 2.6 us; pure Python code takes no simulation time), real-time jitter. The model's own
choices: the board's IP address (192.168.1.51 for PI1), the boot time, the router; the simulation runs below real time.

VERSION
TEP Raspberry Pi 3 Model A+ library V1.0 (Oct 2026). Device RASPBERRY PI 3 MODEL A+ (TEPRPI3AP.LIB / TEPNET.DLL with
TEPPi: Python 3.11.9 and the TEP Pi runtime 0.2). Demo program message_board.py V1.0, blink.py.