i also have a bluepill board. When i connect usb to my win10 notebook i also have “Unknown device” error. I got working serial1, serial2, serial3 but can’t use USB.
Tried both latest stable and upstream platform with same result.
I even tried maple core (with no errors during compiling) but using it my test code don’t work at all.
I modified my bluepill with famous 1,5k resistor in place of 10k wrong one.
There is something wrong or missing?
; platform = ststm32 ; latest stable development platform
; platform = ststm32@~4.5.0 ; custom stable development platform
platform = https://github.com/platformio/platform-ststm32.git ; upstream development platform
; board_build.core = maple
board = bluepill_f103c8
framework = arduino
upload_protocol = stlink
My test code
#define LED_BUILTIN PC13
Serial1.println("Serial LED OFF");
Serial.println("Serial zero LED OFF");
Serial2.println("Serial DUE LED OFF");
Serial3.println("Serial TRE LED OFF");
Serial1.println("Serial LED ON");
Serial.println("Serial zero LED ON");
Serial2.println("Serial DUE LED ON");
Serial3.println("Serial TRE LED ON");