How to make printf work on STM32F103?

Question

I am new to the world of STM32F103. I have a demo code for STM32F103 and I am using arm-none-eabi to compile it.

I tried what I could find on Google, but nothing wor

Answer 1

Look there. This is printf from glib. But you have microcontroller. So you sould write own printf, where vfprintf will return result into buffer and next you will send data from buffer to UART. Kind of

void printf( const char * format, ... )
{
  char buffer[256];
  va_list args;
  va_start (args, format);
  vsprintf (buffer,format, args);
  send_via_USART1 (buffer);
  va_end (args);
}

Also you can write own vsprintf. Standart vsprintf is very heavy. Usually little part of vsprintf features is used.