Steps needed to setup STM32F103C8 (Blue Pill)

Files in this repo

• hid-flash.exe, not sure anymore
• st-flash.exe, st-info.exe and st-util.exe from https://github.com/texane/stlink if you want to manually upload the bootloader
• win_drivers.7z: Windows drivers for the STM32 when using the stm32duino bootloader
• stm32-pio-blink: Basic blink sketch using PlatformIO

Rough steps to getting the STM32F103C8 working:

• Note: The generic blue boards do not come with the micro-USB enabled.
• You must flash the bootloader with generic_boot20_pc13.bin (assuming LED is PC13)
• Obtain STM32duino bootloader from https://github.com/rogerclarkmelbourne/STM32duino-bootloader/tree/master/binaries
• Easiest way to flash is via STLINK V2 and STM32CubeProg https://www.st.com/en/development-tools/stm32cubeprog.html
• To flash set Boot1 jumper to 1 then unplug/replug. LED should flash quickly.
• Note: Other pages say set Boot0 to 1...for me setting Boot1 to 1 worked.
• Connect via STM32CubeProg and select the .bin file, use address 0x08000000, size 0x400 and Data width 32-bit. Press Download.
• Important: After download complete, you must select Boot1 back to pin 0 before resetting the board!
• Now connect micro-USB to computer. A new USB Serial Device should appear under Ports (COM & LPT) in Windows Device Manager.
• Ensure Maple DFU appears in Windows Device Manager after flashing.
• Note: If you get Couldn't find the DFU device: [1EAF:0003] when uploading a sketch, then manually reset the device using the onboard push button.
• If uploading a sketch still fails, reflash using the above bootloader again.
• If USB port doesn't appear after sketch upload or Windows complains and disabled the device, then see USB resistor problem below.

Arduino IDE

• Using Arduino IDE, Google how to setup the IDE first.
• Upload settings
  • Board: Generic STM32F1
  • Board part number: Blue Pill F103C8
  • USART support: Enabled (generic Serial)
  • USB support: CDC (generic Serial). <- Important, if you don't enable this, you won't get COM port after upload.
  • Upload method: Maple DFU Bootloader 2.0
  • Port: [Check Windows Device Manager]

PlatformIO: USB Upload and Serial

• Install PlatformIO extension in VS Code
• See https://docs.platformio.org/en/latest/boards/ststm32/bluepill_f103c8.html
• Use the following platformio.ini settings after creating a project

[env:genericSTM32F103CB]
platform = ststm32
board = genericSTM32F103C8
framework = arduino
upload_port = COM9
upload_protocol = dfu

PlatformIO: ST-Link V2 Upload, debug and Serial interface (Recommended)

• Upload is done via ST-Link V2
• Can debug sketches directly in VS Code (Press F5)
• Use the following platformio.ini settings

[env:BLUEPILL_F103C8]
platform = ststm32
board = bluepill_f103c8_128k
framework = arduino
upload_port = COM9
upload_protocol = stlink
build_flags =
  -D PIO_FRAMEWORK_ARDUINO_NANOLIB_FLOAT_PRINTF  
  -D PIO_FRAMEWORK_ARDUINO_ENABLE_CDC
  -D USBCON
  -D USBD_VID=0x0483
  -D USB_MANUFACTURER="Unknown"
  -D USB_PRODUCT="\"BLUEPILL_F103C8\""
  -D HAL_PCD_MODULE_ENABLED

• Note: If upload fails with Warn : UNEXPECTED idcode: 0x2ba01477 Error: expected 1 of 1: 0x1ba01477 then edit .platformio/packages/tool-openocd/scripts/target/stm32f1x.cfg and change set _CPUTAPID 0x1ba01477 to set _CPUTAPID 0x2ba01477
• Note: .platformIO is in %HOMEPATH%\.platformio on Windows

USB resistor problem

• The D+ of micro USB has a wrong resistor R10 value. It should be 1.5k ohm.
• Check the resistance between pin A12 and 3.3v. If not 1.6k ohm, replace R10. I removed it and soldered a regular 1.5k resistor on above the board between A12 and 3.3v.

References

• https://youtu.be/wGbiT6IxGP0
• https://www.onetransistor.eu/2017/11/stm32-bluepill-arduino-ide.html
• https://github.com/Serasidis/STM32_HID_Bootloader
• https://donneyfan.com/blog/usb-serial-for-blue-pill-stm32-with-platformio
• https://github.com/stm32duino/wiki/wiki/Upload-methods
• https://github.com/stm32duino/Arduino_Core_STM32
• https://circuitdigest.com/microcontroller-projects/getting-started-with-stm32-development-board-stm32f103c8-using-arduino-ide
• https://docs.platformio.org/en/latest/boards/ststm32/bluepill_f103c8.html
• http://reblag.dk/stm32/

Further Reading

• https://medium.com/swlh/super-blue-pill-like-stm32-blue-pill-but-better-6d341d9347da