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/*
stm32f4_usart.c
David Rowe May 2019
Basic USART tty support for the stm32.
From:
http://stm32projectconsulting.blogspot.com/2013/04/stm32f4-discovery-usart-example.html
*/
#include <stm32f4xx.h>
#include <stm32f4xx_usart.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include "stm32f4_usart.h"
#define MAX_FMT_SIZE 256
void usart_init(void){
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
/* enable peripheral clock for USART3 */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
/* GPIOB clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
/* GPIOA Configuration: USART3 TX on PB10 */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Connect USART3 pins to AF2 */
// TX = PB10
GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_USART3);
USART_InitStructure.USART_BaudRate = 115200;
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_Tx;
USART_Init(USART3, &USART_InitStructure);
USART_Cmd(USART3, ENABLE); // enable USART3
}
void usart_puts(const char s[]) {
for (int i=0; i<strlen(s); i++) {
USART_SendData(USART3, s[i]);
while (USART_GetFlagStatus(USART3, USART_FLAG_TC) == RESET);
}
}
int usart_printf(const char *fmt, ...)
{
char s[MAX_FMT_SIZE];
va_list ap;
va_start(ap, fmt);
vsnprintf(s, MAX_FMT_SIZE, fmt, ap);
va_end(ap);
usart_puts(s);
return 1;
}
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