编写一个可以在keil5上执行的stm32串口接收ascii码的程序

好的，针对您的问题，我可以给您提供以下伪代码：

#include <stdio.h>
#include "stm32f10x.h"

int main(void)
{
USART_InitTypeDef USART_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

/* Enable GPIO clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

/* Enable USART clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

/* Configure USART Tx and Rx pins */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure);

/* Configure USART */
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(USART1, &USART_InitStructure);

/* Enable USART */
USART_Cmd(USART1, ENABLE);

while (1)
{
if (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == SET)
{
uint8_t data = USART_ReceiveData(USART1);

/* Handle received data here */
}
}
}

需要注意的是，此伪代码是基于 STM32F10x 系列芯片，使用的是 USART1，波特率为 9600。您需要根据实际需要进行修改，包括引脚配置、波特率等。