usart1.c
#include "usart1.h"
#define G_DMA_RX_LEN 100
#define G_DMA_TX_LEN 100
uint8_t g_dma_rx_buff[G_DMA_RX_LEN];
uint8_t g_dma_tx_buff[G_DMA_TX_LEN];
uint16_t g_tx_buff_len = 0;
static void Usart1GpioInit(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(USART1_GPIO_CLK,ENABLE); //使能GPIOA时钟
GPIO_InitStructure.GPIO_Pin = USART1_GPIO_PIN; //GPIOA9与GPIOA10
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //速度50MHz
GPIO_Init(USART1_GPIO_PORT,&GPIO_InitStructure); //初始化PA9,PA10
//串口1对应引脚复用映射
GPIO_PinAFConfig(USART1_GPIO_PORT,USART1_TX_SOURCE,USART1_TX_AF); //GPIOA9复用为USART1
GPIO_PinAFConfig(USART1_GPIO_PORT,USART1_RX_SOURCE,USART1_RX_AF); //GPIOA10复用为USART1
}
static void Usart1Config(void)
{
USART_InitTypeDef USART_InitStructure;
RCC_APB2PeriphClockCmd(USART1_CLK,ENABLE); //使能USART1时钟
//USART1 初始化设置
USART_InitStructure.USART_BaudRate = USART1_BAUDRATE; //波特率设置
USART_InitStructure.USART_WordLength = USART_WordLength_8b; //字长为8位数据格式
USART_InitStructure.USART_StopBits = USART_StopBits_1; //一个停止位
USART_InitStructure.USART_Parity = USART_Parity_No; //无奇偶校验位
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //收发模式
USART_Init(USART1, &USART_InitStructure); //初始化串口1
}
static void Usart1NvicInit(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
//Usart1 NVIC 配置
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn; //串口1中断通道
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1; //抢占优先级1
NVIC_InitStructure.NVIC_IRQChannelSubPriority =3; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure);
}
static void Usart1DmaRxInit(void)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHB1PeriphClockCmd(USART1_DMA_CLK,ENABLE); //DMA2时钟使能
DMA_DeInit(USART1_RX_DMA_STREAM);
while (DMA_GetCmdStatus(USART1_RX_DMA_STREAM) != DISABLE){} //等待DMA可配置
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable ;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full ;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single ; //存储器突发单次传输
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
// DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; // DMA_Mode_Circular DMA_Mode_Normal
DMA_InitStructure.DMA_PeripheralBaseAddr =(uint32_t) (&(USART1->DR)) ;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
/* Configure RX DMA */
DMA_InitStructure.DMA_Channel = USART1_RX_DMA_CHANNEL ;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; // DMA_Mode_Circular DMA_Mode_Normal
DMA_InitStructure.DMA_BufferSize = G_DMA_RX_LEN;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory ;
DMA_InitStructure.DMA_Memory0BaseAddr =(uint32_t)g_dma_rx_buff;
DMA_Init(USART1_RX_DMA_STREAM,&DMA_InitStructure);
DMA_Cmd(USART1_RX_DMA_STREAM,ENABLE); //开启接收
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);
}
static void Usart1DmaTxInit(void)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2,ENABLE); //DMA2时钟使能
DMA_DeInit(USART1_TX_DMA_STREAM);
while (DMA_GetCmdStatus(USART1_TX_DMA_STREAM) != DISABLE){} //等待DMA可配置
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable ;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full ;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single ; //存储器突发单次传输
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
// DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; // DMA_Mode_Circular DMA_Mode_Normal
DMA_InitStructure.DMA_PeripheralBaseAddr =(uint32_t) (&(USART1->DR)) ;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
/* Configure TX DMA */
DMA_InitStructure.DMA_Channel = USART1_RX_DMA_CHANNEL ;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; // DMA_Mode_Circular DMA_Mode_Normal
DMA_InitStructure.DMA_BufferSize = G_DMA_TX_LEN;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral ;
DMA_InitStructure.DMA_Memory0BaseAddr =(uint32_t)g_dma_tx_buff ;
DMA_Init(USART1_TX_DMA_STREAM,&DMA_InitStructure);
USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE);
}
void Usart1Init(void)
{
Usart1GpioInit();
Usart1Config();
Usart1NvicInit();
Usart1DmaRxInit();
Usart1DmaTxInit();
USART_ClearITPendingBit(USART1, USART_IT_IDLE); //开启串口接受中断
USART_ITConfig(USART1, USART_IT_IDLE, ENABLE); //开启空闲中断
USART_Cmd(USART1, ENABLE); //使能串口1
}
void Usart1DmaSend(uint8_t *data_buf, uint16_t lengh)
{
DMA_Cmd(USART1_TX_DMA_STREAM,DISABLE);
Waiting_Disable_DMA(USART1_TX_DMA_STREAM);
//DMA_ITConfig(USART1_TX_DMA_STREAM,DMA_IT_FE,ENABLE);
//解析接收到的数据
memset(g_dma_tx_buff, 0,G_DMA_TX_LEN );
memcpy(g_dma_tx_buff,data_buf,lengh);
/* Clear DMA Transfer Complete Flags */
DMA_ClearFlag(USART1_TX_DMA_STREAM,DMA_FLAG_TCIF7);
/* Clear USART Transfer Complete Flags */
USART_ClearFlag(USART1,USART_FLAG_TC);
DMA_SetCurrDataCounter(USART1_TX_DMA_STREAM,lengh);
DMA_Cmd(USART1_TX_DMA_STREAM,ENABLE);
}
void DMA2_Stream2_IRQHandler(void)
{
uint16_t lengh=0;
//清除标志
if(DMA_GetFlagStatus(USART1_RX_DMA_STREAM,DMA_FLAG_TCIF2)!=RESET)//等待DMA2_Steam7传输完成
{
DMA_Cmd(USART1_RX_DMA_STREAM, DISABLE); //关闭DMA,防止处理其间有数据
lengh = G_DMA_RX_LEN - DMA_GetCurrDataCounter(USART1_RX_DMA_STREAM);
DMA_ClearFlag(USART1_RX_DMA_STREAM,DMA_FLAG_TCIF2 | DMA_FLAG_FEIF2 | DMA_FLAG_DMEIF2 | DMA_FLAG_TEIF2 | DMA_FLAG_HTIF2);//清除DMA2_Steam7传输完成标志
DMA_SetCurrDataCounter(USART1_RX_DMA_STREAM, G_DMA_RX_LEN);
memcpy(g_dma_tx_buff,g_dma_rx_buff,lengh);
g_tx_buff_len = lengh;
//发送数据
Usart1DmaSend(g_dma_tx_buff,g_tx_buff_len);
DMA_Cmd(USART1_RX_DMA_STREAM, ENABLE); //打开DMA,
}
}
#ifndef __USART1_H
#define __USART1_H
#include "stm32f4xx.h"
#include <stdio.h>
#include <string.h>
//GPIO
#define USART1_GPIO_PIN (GPIO_Pin_9 | GPIO_Pin_10)
#define USART1_GPIO_CLK RCC_AHB1Periph_GPIOA
#define USART1_GPIO_PORT GPIOA
#define USART1_RX_AF GPIO_AF_USART1
#define USART1_RX_SOURCE GPIO_PinSource10
#define USART1_TX_AF GPIO_AF_USART1
#define USART1_TX_SOURCE GPIO_PinSource9
// USART1
#define USART1_CLK RCC_APB2Periph_USART1
#define USART1_BAUDRATE 115200
// DMA
#define USART1_DMA_CLK RCC_AHB1Periph_DMA2
#define USART1_RX_DMA_CHANNEL DMA_Channel_4
#define USART1_RX_DMA_STREAM DMA2_Stream2
#define USART1_TX_DMA_CHANNEL DMA_Channel_4
#define USART1_TX_DMA_STREAM DMA2_Stream7
void Usart1Init(void);
uint8_t Usart1IsReady(void);
void Usart1DmaSend(uint8_t *data_buf, uint16_t lengh);
#endif /* __USART1_H */
main.c
#include "stm32f4xx.h"
#include "systick.h"
#include "usart1.h"
int main()
{
uint8_t data_Buffer[8]= {01,02,03,04,05,06,07};
Usart1Init();
//printf("That OK!\n");
while(1)
{
Usart1DmaSend(data_Buffer,8);
Delay_ms(500);
Usart1IsReady();
Delay_ms(500);
}
}