Project Files of STM32 Nucleo-F401RE Library for Proteus: BMP280 Data Logger

STM32 NUCLEO-F401RE LIBRARY FOR PROTEUS - V1.0 (YOUR STM32F401 SKETCH, ARDUINO SHIELDS, A WEATHER DATA LOGGER)
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/stm32-nucleo-f401re-library-for-proteus.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/stm32-nucleo-f401re-proteus-library
The demo's parts are our libraries (included) - their articles:
  BMP280:              https://www.theengineeringprojects.com/2026/09/bmp280-proteus-library.html
  DS3231:              https://www.theengineeringprojects.com/2026/10/ds3231-rtc-module-library-for-proteus-v1-0.html
  Ethernet Shield 2:   https://www.theengineeringprojects.com/2026/10/arduino-ethernet-shield-2-library-for-proteus.html
  Laptop and phone:
    https://www.theengineeringprojects.com/2026/10/laptop-wifi-monitor-library-for-proteus.html
    https://www.theengineeringprojects.com/2026/10/mobile-wifi-monitor-library-for-proteus.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
STM32-Nucleo-F401RE-TEP-v1.0/
|-- Proteus Library Files/
|   |-- TEPBMP280.LIB                                    73.9 KB   the BMP280 (demo), to LIBRARY
|   |-- TEPDS3231.LIB                                    68.9 KB   the DS3231 clock (demo), to LIBRARY
|   |-- TEPETHSHIELD2.LIB                                33.8 KB   the Ethernet Shield 2 (demo), to LIBRARY
|   |-- TEPLAPTOP.LIB                                    39.5 KB   the laptop (demo), to LIBRARY
|   |-- TEPMOBILE.LIB                                    13.1 KB   the phone (demo), to LIBRARY
|   |-- TEPNUCLEOF401RE.LIB                              52.8 KB   the STM32 Nucleo-F401RE, to LIBRARY
|-- Proteus Model Files/
|   |-- TEPBMP280.DLL                                   537.0 KB   the BMP280, to MODELS
|   |-- TEPDS3231.DLL                                   321.5 KB   the DS3231 clock, to MODELS
|   |-- TEPNET.DLL                                       2.46 MB   the board + monitors + network, to MODELS
|-- Arduino Code/
|   |-- Nucleo_Weather_Logger/Nucleo_Weather_Logger.ino   11.5 KB   the demo sketch
|   |-- TEP Boards for Proteus/hardware/                724.5 KB   the Arduino IDE add-on 1.27.0 (168 files)
|-- Proteus Simulation/
|   |-- Nucleo_Weather_Logger.hex                       120.7 KB   the demo sketch (U1)
|   |-- Nucleo-Weather-Logger.pdsprj                     34.4 KB   the demo: a weather data logger
|   |-- TEPBMP280.DLL                                   537.0 KB   copy of the model
|   |-- TEPDS3231.DLL                                   321.5 KB   copy of the model
|   |-- TEPNET.DLL                                       2.46 MB   copy of the model
|-- README.txt                                          ~14.6 KB   this file
Total: 7.76 MB (unzipped). The source code of the models is not included.

WHAT IS IT?
Proteus 8 has no STM32F401 (ARM Cortex-M4) processor model, so this is NOT a real STM32. It is ST's NUCLEO-F401RE - the
white NUCLEO-64 board with the STM32F401RET6, the ST-LINK/V2-1 debugger on its break-off end (mini-USB, LD1 COM), the
blue USER button B1, the black RESET button B2, the green LD2 and the red LD3, the Arduino UNO R3 headers and the two
ST Morpho headers - that runs YOUR STM32 sketch in Proteus:
  * You write a normal Nucleo sketch with the Arduino pin numbers or the STM32 names of the header pins (D0 .. D15,
    A0 .. A5, PA5, PB8 ..., LED_BUILTIN = PA5, USER_BTN = PC13, Serial, Serial1, Wire, SPI, analogRead 0 .. 1023,
    analogWrite, attachInterrupt ...) and compile it in the Arduino IDE with our board package "TEP Boards for Proteus"
    1.27.0 (in Arduino Code - see INSTALLATION).
  * Inside the board, Proteus's own ATmega2560 model runs the compiled sketch at 16 MHz; our model (TEPNET.DLL) wraps
    it: the 22 Arduino header pins with their STM32 names, 3.3 V logic, analogRead on A0 .. A5 (0 .. 1023 for 0 ..
    3.3 V), B2 RESET, B1 USER (PC13 LOW while pressed), LD2 on PA5 (D13, lit when HIGH), LD3 (power) and the built-in
    serial monitor on the ST-LINK USB (Serial).
  * The Nucleo takes Arduino shields. The demo plugs our Arduino Ethernet Shield 2 on it: the W5500 on SPI puts the
    board on our virtual router TEP-WiFi with the Laptop and Mobile WiFi Monitors, and the shield's micro SD card keeps
    a log.
TEP additions: the mini-USB port opens the serial monitor; the LEDs glow in the simulation. There is no panel: the board
has no Wi-Fi.
Limits (say them before you start): 16 MHz, 8 KB of RAM (the real STM32F401: 84 MHz, 96 KB), 256 KB of flash; int is 16
bits (use long / int32_t for big numbers); only the Arduino header pins are modelled (the Morpho pins that are on no
Arduino header are drawn); the STM32's own peripherals (HAL, LL, the timers, DMA and the DSP instructions by register,
the RTC) are not there - write Arduino code, not registers. See MODEL SCOPE AND LIMITS.

ONE DEVICE (search "NUCLEO" or "STM32" in Pick Devices):
  STM32 NUCLEO-F401RE  "STM32 Nucleo-F401RE" V1.0 (Microprocessor ICs > STM32 Boards), prefix U, model TEPNET.DLL. The
  serial monitor (115200 baud) has Monitor, Plotter and Board tabs (the Board tab: the LEDs, B2, B1, every pin). Like
  every TEP window it has no Windows title bar.
The same TEPNET.DLL also runs our other sketch boards, the Ethernet Shield 2 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 26 Oct 2026 with the demo project as shipped. What the Proteus run showed:
* Nucleo-Weather-Logger: the monitor printed "BMP280 ready, DS3231 ready, SD card ready", "W5500: 192.168.1.90, link
  ON", "Page: http://192.168.1.90/", then "2026-03-21 08:00:00  25.0 C  1013.2 hPa  STEADY" every 2 s (the DS3231 set
  to 2026-03-21 08:00:00); LD3 on, LD2 lit by the SPI clock; LOG.CSV on the shield's card.
* The laptop (192.168.1.21) and the phone (192.168.1.41) opened http://192.168.1.90/ (HTTP 200).
* STORM on the BMP280's pop-up: "22.0 C  980.0 hPa  FALLING", ">> Pressure FALLING: rain or a storm on the way"; LOG
  on the laptop: the end of LOG.CSV; MARK on the phone: ">> Mark 1 at 2026-03-21 08:00:16 (the web page)"; SEA LEVEL:
  ">> Pressure STEADY", then ">> Pressure RISING: fair weather ahead".
* About 32 s of simulation in 218 s, with the three pop-ups, the monitor and both tools open; no errors.

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). TEPNUCLEOF401RE.LIB is the
   board; the others are the demo's parts: TEPBMP280.LIB, TEPDS3231.LIB, TEPETHSHIELD2.LIB, TEPLAPTOP.LIB and
   TEPMOBILE.LIB.
3. Copy the DLLs from "Proteus Model Files" (TEPNET.DLL, TEPBMP280.DLL, TEPDS3231.DLL) to the MODELS folder (...\Proteus
   8 Professional\MODELS) - replace an older TEPNET.DLL (this one is the first that knows the Nucleo-F401RE).
4. Delete TEPNUCLEOF401RE.IDX from the LIBRARY folder if it is there.
5. The Arduino IDE (only to compile your own sketches - the demo has its HEX file): copy the folder
   "Arduino Code\TEP Boards for Proteus\hardware" into your sketchbook folder (normally Documents\Arduino), so that
   Documents\Arduino\hardware\tep\avr\boards.txt exists (replace an older copy); restart the IDE. The Arduino AVR Boards
   platform must be installed (it comes with IDE 1.8.x; in IDE 2.x install "Arduino AVR Boards" from the Boards Manager
   once). Tools > Board > TEP Boards for Proteus > STM32 Nucleo-F401RE (TEP Proteus). The demo also needs Ethernet, SD,
   Adafruit BMP280, Adafruit Unified Sensor, Adafruit BusIO and RTClib (Library Manager).
6. Start Proteus. In Pick Devices (P) search "NUCLEO".

RUN THE DEMO
Keep the .hex file and the DLLs beside the project in "Proteus Simulation".
Nucleo-Weather-Logger.pdsprj - U1 the Nucleo-F401RE (Nucleo_Weather_Logger.hex) is a barometer that keeps a diary:
U3 = the BMP280 (I2C address 0x76: SDO on GND, CSB on VCC for I2C) and U4 = the DS3231 clock (0x68) on one I2C bus (SDA
D14 / PB9, SCL D15 / PB8); U2 = the Arduino Ethernet Shield 2 on SPI (MOSI D11, MISO D12, SCK D13): its W5500 (CS D10,
the fixed address 192.168.1.90) and its micro SD card (CS D4, an empty card at Run). PC1 the Laptop WiFi Monitor and
MOB1 the Mobile WiFi Monitor open http://192.168.1.90/. The BMP280 and the DS3231 are the Advance versions: each opens
its pop-up window at Run, as the shield does.
Every 2 s the sketch reads the temperature and the pressure, stamps them with the DS3231's date and time (the demo
starts the clock at 2026-03-21 08:00:00: the DS3231's TIME property) and appends a line to LOG.CSV on the card:
date,time,temperature_c,pressure_hpa. The pressure trend compares the newest reading with the one 10 s before: more than
0.5 hPa up is RISING (fair weather ahead), down is FALLING (rain or a storm on the way), else STEADY - a real station
compares 3 hours, the demo is quicker. The blue USER button B1 (PC13) writes a MARK line into the log (an event); so do
the page's MARK link and the monitor's MARK command.
Press Run. The monitor prints the address and a line every 2 s. On the BMP280's pop-up click STORM: the pressure drops
and the monitor says ">> Pressure FALLING". LOG on the laptop shows the end of LOG.CSV; MARK on the phone; SEA LEVEL on
the BMP280: RISING.
The modules' supplies: in the demo the VCC of the BMP280, the DS3231 and the shield go to Proteus' power rail (power
terminals) - their models read the supply as a digital level, which the board's +3V3 and +5V (analog sources) do not
give them; on a real board the shield sits on the headers and the modules on +3V3. Closed the monitor? Click the
board's mini-USB port. The monitor (115200) takes STATUS, LOG, NEW, MARK, TIME YYYY-MM-DD HH:MM:SS and HELP.
LD2 is D13, SPI's clock: with the shield on the bus it flickers (on the real board too) - not a user LED any more.

THE PINS (the label on the board, the STM32 pin, what it can do in the simulation)
  D0 / D1            PA3 / PA2: GPIO, PWM, interrupt (on the real board Serial's lines to the ST-LINK)
  D2 / D8            PA10 / PA9: Serial1 RX / TX (USART1), GPIO
  D3 .. D7, D9       PB3, PB5, PB4, PB10, PA8, PC7: GPIO, PWM, interrupt
  D10 .. D13         PB6, PA7, PA6, PA5: SPI SS / MOSI / MISO / SCK, GPIO; D13 is also LD2
  D14 / D15          PB9 / PB8: Wire SDA / SCL (I2C), GPIO
  A0 .. A5           PA0, PA1, PA4, PB0, PC1, PC0: analogRead 0 .. 1023 for 0 .. 3.3 V, GPIO, PWM, interrupt
  RESET              B2 / NRST (LOW holds the board in reset)
  +3V3, +5V, IOREF   3.3 V (the logic), 5 V, 3.3 V;  GND  ground
  AVDD, VIN, NC      drawn, not modelled
B1 USER is PC13 (USER_BTN, LOW while pressed). Serial is the ST-LINK USB (the board's monitor), not D0 / D1. The pins
are 3.3 V logic.

PROPERTIES (double-click the board > Edit Properties)
  PROGRAM   the sketch's HEX (Arduino IDE: Sketch > Export Compiled Binary with STM32 Nucleo-F401RE (TEP Proteus))
  MONITOR   YES = the built-in serial monitor on the ST-LINK USB (Serial);  BAUD  its speed (115200, or AUTO)
  AUTOOPEN  YES = the monitor window opens at Run (the demo: YES)
One Nucleo per design (its USB serial lines and B1 are hidden pins, and Proteus joins hidden pins of the same name
across parts).

TROUBLESHOOTING
* Nothing happens at Run: the HEX was not built with TEP Boards for Proteus - select STM32 Nucleo-F401RE (TEP Proteus)
  and export the binary again.
* "BMP280 NOT FOUND": SDA on D14, SCL on D15, CSB on VCC (CSB LOW switches it to SPI), SDO on GND (0x76) or VCC (0x77).
* "NO SD CARD": the shield's SDCS on D4, its CS on D10 HIGH while SD.begin() runs (the demo sets both HIGH first); the
  shield's SDCARD property must not be NONE.
* "link OFF": the shield's CABLE property is OUT, or its VCC has no digital supply (the power terminal, as in the demo).
* The times show 2000-01-01: the DS3231's TIME is LOST or its BATTERY is OUT - set TIME (PC or a date) or send TIME.
* An integer goes wrong above 32767: int is 16 bits on the hidden AVR - use long.
* The page shows old values: tap REFRESH (the monitors do not reload by themselves).

BUG REPORTS AND FEATURE REQUESTS
Please post them in our forum with a screenshot and the Serial Monitor text:
  https://www.theengineeringprojects.com/forum/category/stm32-nucleo-f401re-proteus-library

LICENCES AND THIRD-PARTY NOTES
* The board model and the network (TEPNET.DLL, which also runs the Ethernet Shield 2), the symbols and artwork
  (TEPNUCLEOF401RE.LIB, TEPETHSHIELD2.LIB, TEPLAPTOP.LIB, TEPMOBILE.LIB) and the module models (TEPBMP280, TEPDS3231
  .LIB / .DLL) are made by The Engineering Projects. The board's processor is Proteus's own ATmega2560 model. The source
  code of the models is not included.
* TEP Boards for Proteus (Arduino Code): its core, the variants and the EEPROM, SPI and Wire libraries are modified
  copies of the Arduino AVR core 1.8.6 - GNU Lesser General Public License 2.1 (LGPL 2.1, the text:
  LICENSE-LGPL-2.1.txt); its other libraries and our core files are MIT (LICENSE-MIT.txt).
* The demo sketch uses Ethernet and SD (Arduino, LGPL / GPL), Adafruit BMP280, Adafruit Unified Sensor, Adafruit BusIO
  and RTClib (BSD / MIT / Apache) - install them in the Arduino IDE (Library Manager) to compile it; the .hex is
  included.
* Proteus is a product of Labcenter Electronics and is not included. STM32 and Nucleo are trademarks of
  STMicroelectronics. This library is not made or endorsed by STMicroelectronics or by Labcenter.

REBUILDING THE FIRMWARE (OPTIONAL)
The HEX file is supplied. Install TEP Boards for Proteus (INSTALLATION step 5) and the libraries, open Arduino
Code\Nucleo_Weather_Logger, select STM32 Nucleo-F401RE (TEP Proteus) and use Sketch > Export Compiled Binary. For a real
Nucleo-F401RE install "STM32 MCU based boards" (STM32duino) in the Boards Manager, select "Nucleo-64" with the board
part number "Nucleo F401RE" and upload over the ST-LINK (it shows up as a USB drive) - the same sketch.

MODEL SCOPE AND LIMITS
Modelled: the Nucleo's 22 Arduino header pins on a hidden ATmega2560 (Proteus's AVR model, 16 MHz, 3.3 V); digital I/O,
analogRead (A0 .. A5) 0 .. 1023 for 0 .. 3.3 V, PWM (analogWrite) and attachInterrupt on any pin through the board
model; B2 RESET, B1 USER on PC13, LD2 on PA5, LD3 (power); Serial (the ST-LINK USB, the board's monitor), Serial1 on D8
/ D2, Wire on D14 / D15 and SPI on D10 .. D13 (the AVR's hardware); Ethernet through a TEP Ethernet Shield 2 or W5500
module. Not modelled: the STM32F401 itself (84 MHz, 96 KB RAM, the FPU and DSP, HAL / LL, its timers, DMA, the RTC, USB
OTG), the Morpho pins that are on no Arduino header, the ST-LINK (LD1 COM, CN2, SWD: drawn), JP5 and the solder bridges.
The ST-LINK's mass-storage upload is not used (Proteus loads the HEX). The simulation runs below real time.

VERSION
TEP STM32 Nucleo-F401RE library V1.0 (Oct 2026). Device STM32 NUCLEO-F401RE (TEPNUCLEOF401RE.LIB / TEPNET.DLL), TEP
Boards for Proteus 1.27.0 (adds the Nucleo-F401RE). Demo sketch Nucleo_Weather_Logger V1.0. Demo parts: BMP280 and
DS3231 (the Advance versions), ARDUINO ETHERNET SHIELD 2 W5500, LAPTOP WIFI MONITOR and MOBILE WIFI MONITOR.