[STM32F103C8T6] SPI1 does not send any data #2762

Toy-Jie · 2025-06-30T20:41:10Z

Toy-Jie
Jun 30, 2025

STM32F103C8T6

RCC->APB2ENR |= RCC_APB2ENR_AFIOEN;
AFIO->MAPR |= AFIO_MAPR_SPI1_REMAP;

SPI.begin();
SPI.transfer(0xAA);

SCK -> PB3
MISO -> PB4
MOSI -> PB5

Using an oscilloscope to check, no data is transmitted.

fpistm · 2025-06-30T21:09:07Z

Which target you used? Generic? BluePill?

1 reply

As far as I can tell (as I don't know your configuration), you use the default SPI instance but it does not use the pin you expect.
So change them following this wiki and no need to access registers it is done by the SPIClass.
https://github.com/stm32duino/Arduino_Core_STM32/wiki/API#change-default-spi-instance-pins