Arduino for STM32

Posted: **Sat Jul 23, 2022 1:38 pm**

Hi All

I bought this board a couple of years ago and have just got around to playing with it. The MCU is a STM32L475 and the chip has VGT6 stamped on it.

I went through a ST tutorial of using the STMCubeIDE and STMCubeMX to flash the LED and that works fine, so I think the toolchain is OK

I decided to try some programming through the Arduino IDE , to play with the built in sensors and maybe attach the board to Blynk. I found the board library on github (https://github.com/stm32duino/BoardMana ... index.json) and installed that. The library exposed the boards as excepted and I chose Generic STM32L4 series and part number L475VGTx . When the libraries where installed, you get some sample code and I chose BarometricPressureSensor. The code compiles OK and uploads to the board, but there is no output to the serial monitor. I am sure the code loads OK as the LED stopped blinking (from ST tutorial)
The compiler output is

-------------------------------------------------------------------
STM32CubeProgrammer v2.11.0
-------------------------------------------------------------------

ST-LINK SN : 066FFF3736324D5043224537
ST-LINK FW : V2J40M27
Board : STM32L4IO
Voltage : 3.22V
SWD freq : 4000 KHz
Connect mode: Under Reset
Reset mode : Hardware reset
Device ID : 0x415
Revision ID : Rev 4

Device name : STM32L4x1/STM32L475xx/STM32L476xx/STM32L486xx
Flash size : 1 MBytes
Device type : MCU
Device CPU : Cortex-M4
BL Version : --
Debug in Low Power mode enabled

Memory Programming ...
Opening and parsing file: BarometricPressureSensor.ino.bin
File : BarometricPressureSensor.ino.bin
Size : 25.29 KB
Address : 0x08000000

Erasing memory corresponding to segment 0:
Erasing internal memory sectors [0 12]
Download in Progress:

File download complete
Time elapsed during download operation: 00:00:00.916

RUNNING Program ...
Address: : 0x8000000
Application is running, Please Hold on...
Start operation achieved successfully

I have left the rest of the tool settings at the default for this board. The code has a conditional output to the serial monitor, thus

Code: Select all

// don't do anything until the data ready pin is high:
  if (digitalRead(dataReadyPin) == HIGH)

To ensure the problem was not the pin being held LOW, I added an unconditional write to the console in Setup(), thus

Code: Select all

 Serial.println("Starting...");

Can anyone tell me what I am doing wrong?

Thanks

Posted: **Sat Jul 23, 2022 2:17 pm**

You have to select the board in discovery menu not generic.
Part number: B-L475E-IOT01A

Posted: **Sat Jul 23, 2022 4:39 pm**

Thanks @fpiSTM

I changed the board/part number as suggested. The download to the MCU was successful, but I had the same result, i.e. no output to the serial monitor.

I thought I'd try something simpler, so downloaded the blink sketch using the discovery settings and that worked, the LED blinked. To be certain I re-downloaded the BarometricPressureSensor sketch to reset the LED and then re-downloaded the blink sketch using the generic board. That downloaded successfully but the LED did not blink. So I now know, as you suggested, I have to use the discovery board. Thanks for putting me straight there. I will look closer at the example BarometricPressureSensor sketch to see if there is anything odd going on, maybe add some delays.

tony

Posted: **Sat Jul 23, 2022 5:41 pm**

OK, I can get data to the serial monitor, I just reversed the test that determines whether or not to read the sensors and output to the monitor.

So is used to say

Code: Select all

  // don't do anything until the data ready pin is high:
  if (digitalRead(dataReadyPin) == HIGH) {
    //Read the temperature data
    int tempData = readRegister(0x21, 2);

and I changed it to

Code: Select all

  // don't do anything until the data ready pin is high:
  if (digitalRead(dataReadyPin) == LOW  ) {
    //Read the temperature data
    int tempData = readRegister(0x21, 2);

Whilst I can get the sketch to output data, the data is rubbish, temp = 3276.7511111, which is suspiciously like 32767 divided by something. I will have to try and find out what is supposed to pull the pin HIGH

Posted: **Sun Jan 28, 2024 11:37 pm**

Is the B-L475E-IOT01A WiFi library still available for Arduino? I could not find it in http://dan.drown.org/stm32duino/package ... index.json.

Also, I was unable to get the Serial.println() to work for Arduino, with the USB cable plugged into the J-Link USB port.

However, I was able to get Serial4.println() working by using an external USB/TTY device:

D1 on PCB silkscreen; A1: Transmit, push/pull
D0 on PCB silkscreen; A0: Receive, open drain

I'm curious how you were able to get the standard Serial.println() to work.

Arduino for STM32

STM32 Discovery kit Iot Node and Arduino

STM32 Discovery kit Iot Node and Arduino

Re: STM32 Discovery kit Iot Node and Arduino

Re: STM32 Discovery kit Iot Node and Arduino

Re: STM32 Discovery kit Iot Node and Arduino

Re: STM32 Discovery kit Iot Node and Arduino