Cannot upload to STM32 blue pill fake after pio update

Advanced Solutions Debugging
7

There is really weird issue that you have to set the (virtual) DTR line now for your to be able to receive data: [CDC] Serial USB without DTR · Issue #1193 · stm32duino/Arduino_Core_STM32 · GitHub

I was able to do this using HTerm - der-hammer and clicking on the “DTR” button in the “input control” section and in PlatformIO per monitor_dtr.

I was just really struggling with this, too.

Also, some of the flags above are not necessary anymore. Please try the following platformio.ini:

[env:genericSTM32F103C8]
platform = ststm32
board = genericSTM32F103C8
framework = arduino
build_flags = 
    ; enable Serial2 and 3
    -D HAVE_HWSERIAL2
    -D HAVE_HWSERIAL3
    ; enable USB serial
    -D PIO_FRAMEWORK_ARDUINO_ENABLE_CDC
    -D USBCON
; QUIRK: without setting this, no  
; data will be received on the serial USB port
; https://github.com/stm32duino/Arduino_Core_STM32/issues/1193
monitor_dtr = 1
; optional: set COM port to monitor here if there are multiple
;monitor_port= COM27

with the following src\main.cpp

#include <Arduino.h>

void setup() { 
    Serial1.begin(115200);
    Serial2.begin(115200);
    Serial3.begin(115200);
    SerialUSB.begin(115200);
    pinMode(PC13, OUTPUT); //blinky
    //while(!Serial); //wait for USB connection
}

void loop() { 
    Serial1.println("Hello from Serial1");
    Serial2.println("Hello from Serial2");
    Serial3.println("Hello from Serial3");
    SerialUSB.println("Hello from SerialUSB");
    SerialUSB.flush();
    digitalWrite(PC13, digitalRead(PC13) ^ 1); //blinky
    delay(500);
}

Then a “upload” and then a “monitor” gives me

> Executing task in folder bluepill_f103c8_128k_repro: C:\Users\Max\AppData\Local\Programs\Python\Python38\Scripts\platformio.exe device monitor --environment genericSTM32F103C8 <

--- Available filters and text transformations: colorize, debug, default, direct, hexlify, log2file, nocontrol, printable, send_on_enter, time
--- More details at http://bit.ly/pio-monitor-filters
--- forcing DTR active
--- Miniterm on COM27  9600,8,N,1 ---
--- Quit: Ctrl+C | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
Hello from SerialUSB
Hello from SerialUSB
Hello from SerialUSB
Hello from SerialUSB
Hello from SerialUSB
Hello from SerialUSB

--- exit ---