- /*
- 主程序如下
- main.c
- 使用中断+DMA数据搬运实现驱动RS-458
- */
- #include "gd32f4xx.h"
- #include "systick.h"
- #define USART1_DATA_ADDRESS ((uint32_t)&USART_DATA(USART1))
- #define RS485BufferSize 256
- uint8_t RS485RxBuffer[RS485BufferSize]={0}; //485数据接收缓冲区
- uint8_t RS485RxP = 0; //485接收缓冲区接收位置指示
- uint8_t RS485RxPre = 0; //485帧头指示
- uint8_t RS485TxBuffer[RS485BufferSize]={0}; //485数据发送缓冲区
- uint8_t RS485TxP = 0; //485发送缓冲区发送位置指示
- uint8_t RS485RxFrameBuffer[RS485BufferSize]; //485接收帧缓冲
- uint8_t RS485RxCount = 0; //485接收计数
- uint8_t RS485RxFlag = 0; //RS485帧接收完成标志,逻辑1有效
- /*485OE使用PE15引脚,高电平发送,低电平接收*/
- void Drv_485OE_Init(void)
- {
- /* 打开GPIOE时钟 */
- rcu_periph_clock_enable(RCU_GPIOE);
- /* 配置PE15口为推挽输出,无上下拉 */
- gpio_mode_set(GPIOE, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN_15);
- gpio_output_options_set(GPIOE, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_15);
- /* 默认485处于接受模式 */
- Drv_485_RxEn();
- }
- // 485 RX_EN
- void Drv_485_RxEn(void)
- {
- gpio_bit_reset(GPIOE, GPIO_PIN_15);
- }
- // 485 TX_EN
- void Drv_485_TxEn(void)
- {
- gpio_bit_set(GPIOE, GPIO_PIN_15);
- }
- //Rs_485初始化
- void Drv_Rs_485_Init(void)
- {
- dma_single_data_parameter_struct dma_init_struct;
- /* enable GPIO clock */
- rcu_periph_clock_enable(RCU_GPIOB);
- /* enable UART clock */
- rcu_periph_clock_enable(RCU_USART2);
- /* configure the USART2 TX pin and USART2 RX pin */
- gpio_af_set(GPIOB, GPIO_AF_7, GPIO_PIN_10); //Tx
- gpio_af_set(GPIOB, GPIO_AF_7, GPIO_PIN_11); //Rx
- /* configure USART2 TX as alternate function push-pull */
- gpio_mode_set(GPIOB, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_10);
- gpio_output_options_set(GPIOB, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_5);
- /* configure USART2 RX as alternate function push-pull */
- gpio_mode_set(GPIOB, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_11);
- gpio_output_options_set(GPIOB, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_6);
- /* USART configure */
- usart_deinit(USART2); //取消初始化USART2
- usart_baudrate_set(USART2, 38400U); //波特率38400U
- usart_receive_config(USART2, USART_RECEIVE_ENABLE);
- usart_transmit_config(USART2, USART_TRANSMIT_ENABLE);
- usart_enable(USART2);
-
- usart_interrupt_flag_clear(USART2, USART_INT_FLAG_ERR_ORERR);
- usart_interrupt_enable(USART2, USART_INT_ERR);
-
- /* USART interrupt configuration */
- nvic_irq_enable(USART2_IRQn, 2, 0); //优先级为2
-
- /* deinitialize DMA0 channel2 (USART0 RX) */
- rcu_periph_clock_enable(RCU_DMA0);
- dma_deinit(DMA0, DMA_CH1);
- dma_init_struct.direction = DMA_PERIPH_TO_MEMORY;
- dma_init_struct.memory0_addr = (uint32_t)RS485RxBuffer;
- dma_init_struct.memory_inc = DMA_MEMORY_INCREASE_ENABLE;
- dma_init_struct.number = sizeof(RS485RxBuffer);
- dma_init_struct.periph_addr = (uint32_t)&USART_DATA(USART2);
- dma_init_struct.periph_inc = DMA_PERIPH_INCREASE_DISABLE;
- dma_init_struct.periph_memory_width = DMA_PERIPH_WIDTH_8BIT;
- dma_init_struct.priority = DMA_PRIORITY_ULTRA_HIGH;
- dma_single_data_mode_init(DMA0, DMA_CH1, &dma_init_struct);
- /* configure DMA mode */
- dma_circulation_enable(DMA0, DMA_CH1); //启用DMA循环模式
- dma_channel_subperipheral_select(DMA0, DMA_CH1, DMA_SUBPERI4);
- /* enable DMA0 channel5 */
- dma_channel_enable(DMA0, DMA_CH1);
- usart_dma_receive_config(USART2, USART_RECEIVE_DMA_ENABLE);
- usart_interrupt_enable(USART2,USART_INT_IDLE); //IDLE线检测中断
-
- /*485 OE引脚初始化*/
- Drv_485OE_Init();
- }
- /*
- void Drv_rs485_Tx(uint8_t *buffer,uint16_t Longth):485发送数据函数
- buffer:数据缓冲区
- Longth:发送数据长度,单位:字节
- */
- void Drv_rs485_Tx(uint8_t *buffer,uint16_t Longth)
- {
- uint16_t i = 0;
- Drv_485_TxEn();
- for(i=0;i<Longth;i++)
- {
- usart_data_transmit(USART2, buffer);
- while(RESET == usart_flag_get(USART2, USART_FLAG_TC));
- }
- Drv_485_RxEn();
-
- }
- //中断服务函数
- void USART2_IRQHandler(void)
- {
- uint16_t i = 0;
- //UART1接收空闲中断处理函数
- if(RESET != usart_interrupt_flag_get(USART2, USART_INT_FLAG_IDLE)){ //总线空闲
- /* clear IDLE flag */
- usart_data_receive(USART2);
- if(RS485RxFlag == 0) //仅在数据处理完成的情况下接收新的帧
- {
- RS485RxCount = RS485BufferSize - (dma_transfer_number_get(DMA0, DMA_CH1));
- for(i=0;i<RS485RxCount;i++)
- {
- RS485RxFrameBuffer = RS485RxBuffer; //将接收缓冲区数据导入帧缓冲区
- }
- if(RS485RxCount > 0)
- {
- RS485RxFlag = 1; //标记收到1帧数据
- }
- }
- //重启DMA
- dma_channel_disable(DMA0, DMA_CH1);
- dma_flag_clear(DMA0, DMA_CH1, DMA_FLAG_FTF);
- dma_transfer_number_config(DMA0, DMA_CH1, RS485BufferSize);
- dma_channel_enable(DMA0, DMA_CH1);
- }
- if(RESET != usart_interrupt_flag_get(USART2, USART_INT_FLAG_RBNE))
- {
- usart_interrupt_flag_clear(USART2, USART_INT_FLAG_RBNE);
- }
- if(RESET != usart_interrupt_flag_get(USART2, USART_INT_FLAG_RBNE_ORERR))
- {
- usart_interrupt_flag_clear(USART2, USART_INT_FLAG_RBNE_ORERR);
- }
- if(RESET != usart_interrupt_flag_get(USART2, USART_INT_FLAG_ERR_NERR))
- {
- usart_interrupt_flag_clear(USART2, USART_INT_FLAG_ERR_NERR);
- }
- if(RESET != usart_interrupt_flag_get(USART2, USART_INT_FLAG_ERR_FERR))
- {
- usart_interrupt_flag_clear(USART2, USART_INT_FLAG_ERR_FERR);
- }
-
- }
- int main(void)
- {
- /**************系统初始化部分**********************/
- SystemInit(); //系统初始化
- systick_config(); //系统时钟加载
- Drv_485OE_Init(); //RS-485驱动初始化
- }
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