一、简介
本章目的：在上一章的基础上，添加串口的功能。可以实现串口的发送，中断接收，以及printf的重定向。
二、从例程移植
找到串口的例程:ModuleDemo\USART\USART_Asyn\USER\USART.uvprojx
关于串口中断的配置，在485的例程工程中有相关内容：
ModuleDemo\USART\USART_Rs485\USER\USART.uvprojx
三、移植
具体的移植过程，不再介绍了，将初始化和中断配置的部分复制过来就可以了。
3.1usart.c
在usart.c中包括初始化，发送单字节函数，printf重定向函数。以及接收中断服务子函数，将收到的数据直接发回。
| #include "usart.h" #include <stdio.h> #include <stdlib.h> #include <string.h> int fputc(int c, FILE *f) { ?????? /* Place your implementation of fputc here */ ?????? /* e.g. write a character to the USART */ ?????? usart1_1_byte(c); ?????? return c; } void uart1_init(uint32_t bound) { ?????? GPIO_InitTypeDef GPIO_InitStructure; ?????? USART_InitTypeDef USART_InitStructure; ?????? NVIC_InitTypeDef NVIC_InitStructe; ?????? ?????? RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE); ?????? RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); ?????? GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; ?????? GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; ?????? GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; ?????? GPIO_Init(GPIOA, &GPIO_InitStructure); ?????? GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; ?????? GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; ?????? GPIO_Init(GPIOA, &GPIO_InitStructure); ?????? USART_InitStructure.USART_BaudRate = bound; ?????? 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; ?????? NVIC_InitStructe.NVIC_IRQChannel = USART1_IRQn; ?????? NVIC_InitStructe.NVIC_IRQChannelCmd = ENABLE; ?????? NVIC_InitStructe.NVIC_IRQChannelPreemptionPriority = 1; ?????? NVIC_InitStructe.NVIC_IRQChannelSubPriority = 0; ?????? NVIC_Init(&NVIC_InitStructe); ?????? ?????? USART_Init(USART1, &USART_InitStructure); ?????? USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//开启串口接受中断 ?????? USART_Cmd(USART1, ENABLE); } void usart1_1_byte(int ch) { ?????? while (!USART_GetFlagStatus(USART1, USART_FLAG_TC)); ?????? USART_SendData(USART1, (uint8_t)ch); ?????? while (!USART_GetFlagStatus(USART1, USART_FLAG_TC)); } void USART1_IRQHandler(void)??????????????? ???? //串口1中断服务程序 { ?????? u8 st,sbuf; ?????? st=USART_GetITStatus(USART1, USART_IT_RXNE); ?????? if(st==SET)? // ?????? { ????????????? sbuf=USART1->DR; ????????????? usart1_1_byte(sbuf); ?????? } } |
3.2usart.h
| #ifndef __USART_H__ #define __USART_H__????????? ?? #include ???? "air32f10x.h" void uart1_init(uint32_t bound); void usart1_1_byte(int ch); #endif |
3.3main.c
main.c中包括初始化等操作。将官方例程中的CLK打印封装到CLK_Printf中。
| #include <stdlib.h> #include <string.h> #include <stdio.h> #include "delay.h" #include "led.h" #include "usart.h" void CLK_Printf(void); int main(void) { ?????? delay_init();?????????????????????? //延时初始化 ?????? uart1_init(115200); ?????? CLK_Printf(); ?????? ?????? LED_GPIO_Init(); ?????? ?????? printf("wuzjjj\r\n"); ?????? while (1) ?????? { ????????????? LEDR_TOGGLE; ????????????? delay_ms(200);//延时200ms ????????????? ????????????? LEDG_TOGGLE; ????????????? delay_ms(200);//延时200ms ????????????? ????????????? LEDB_TOGGLE; ????????????? delay_ms(200);//延时200ms ?????? } } void CLK_Printf(void) { ?????? RCC_ClocksTypeDef clocks; ?????? RCC_GetClocksFreq(&clocks); //获取系统时钟频率 ?????? printf("SYSCLK:%.1fMhz,HCLK:%.1fMhz,PCLK1:%.1fMhz,PCLK2:%.1fMhz,ADCCLK:%.1fMhz\r\n", ????????????? (float)clocks.SYSCLK_Frequency/1000000,(float)clocks.HCLK_Frequency/1000000, ?????? ?????? (float)clocks.PCLK1_Frequency/1000000,(float)clocks.PCLK2_Frequency/1000000,(float)clocks.ADCCLK_Frequency/1000000); } |
四、调试
4.1下载程序
按照上一章的接线图，将A9 A10接到DAP-Link虚拟串口的A2 A3上。
4.2调试结果
复位后，打印当前的时钟频率。
串口发送后将自动回复数据。
