stm32f4-discoveryの作法 その4

概要

stm32f4-discoveryの作法、調べてみた。
serialに、垂れ流す。

サンプルコード

# include "stm32f4_discovery.h"
# include <stm32f4xx.h>
# include <stm32f4xx_usart.h>
# include <stdio.h>
# include <stdarg.h>

void init_usart(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
	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(GPIOA, &GPIO_InitStructure);
	GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2);
	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_Tx;
	USART_Init(USART2, &USART_InitStructure);
	USART_Cmd(USART2, ENABLE);
}
void uart_send(const char * str)
{
	while (* str)
	{
		while (USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);
		USART_SendData(USART2, * str++);
	}
}
void printk(const char * fmt, ...)
{
	char a[256] = {
		'\0'
	};
	va_list ap;
	va_start(ap, fmt);
	vsprintf(a, fmt, ap);
	uart_send(a);
	va_end(ap);
}
void delay(__IO uint32_t nCount)
{
	while(nCount--)
	{
	}
}
int main(void)
{
	init_usart();
	while (1)
	{
		printk("ok\n");
		delay(0xFFFFFF);
	}
}

配線

PA2が、出力。

以上。