Posted on September 09, 2015 at 18:06
I think you're going to have to find yourself some USART pins, and wire up a SiLabs or FTDI USB-to-CMOS Serial type dongle.
/* USART2 PA.2 Tx, PA.3 Rx STM32F0-Discovery sourcer32@gmail.com */
#include ''stm32f0xx.h''
#include ''stm32f0_discovery.h''
int main(void)
{
USART_InitTypeDef USART_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_1);
/* Configure USART2 pins: Rx and Tx ----------------------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
USART_InitStructure.USART_BaudRate = 9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART2, &USART_InitStructure);
USART_Cmd(USART2,ENABLE);
while(1)
{
while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);
USART_SendData(USART2, 'X');
}
}
Through Keil you can retarget the printf functionality
//******************************************************************************
// Hosting of stdio functionality through USART2
//******************************************************************************
#include <
rt_misc.h
>
#pragma import(__use_no_semihosting_swi)
struct __FILE { int handle; /* Add whatever you need here */ };
FILE __stdout;
FILE __stdin;
int fputc(int ch, FILE *f)
{
while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);
USART_SendData(USART2, ch);
return(ch);
}
int fgetc(FILE *f)
{
char ch;
while(USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET);
ch = USART_ReceiveData(USART2);
return((int)ch);
}
int ferror(FILE *f)
{
/* Your implementation of ferror */
return EOF;
}
void _ttywrch(int ch)
{
while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);
USART_SendData(USART2, ch);
}
void _sys_exit(int return_code)
{
label: goto label; /* endless loop */
}
/**************************************************************************************/
The alternative with a Virtual COM port implementation would be the NUCLEO boards, most of which have PA2/PA3 associated with USART2
