最近跟老師一起準備省電子設計競賽了，老師要求先準備好基礎的調試環境，當然選擇usart的調試接收方法啦，由于沒確定這個項目后期會加進來什么功能，不好確定每個包的大小，于是先寫好串口的不定長接收包，想到的方式自然是IDLE+RXNE的查詢
1->
在IDLE里頭通過systick檢測接收空閑的時間，如果空閑時間>10ms就給標記，停止IDLE中斷而去處理這個數據包
//USART1 IRQ handler
- void USART1_IRQHandler(void)
- {
- #if defined (USART_RECIEVE_BY_DMA)
- //handle by DMA + IDLE inquiry
- uint16_t dmaCounter = DMA_GetCurrDataCounter(DMA1_Channel5);
- if ( USART_GetITStatus( USART1 , USART_IT_IDLE ) != RESET ) {
- printf("DMA counter:%d\r\n",dmaCounter);
- //has dealt rx buffer
- // if (dmaCounter != USART_BUFF_SIZE) {
- usartRx.isDeal = false;
- DMA_Cmd(DMA1_Channel5,DISABLE);
- DMA_ClearFlag(DMA1_FLAG_GL3);
- usartRx.buffHead = USART_BUFF_SIZE - dmaCounter;
- DMA_SetCurrDataCounter( DMA1_Channel5 , USART_BUFF_SIZE );
- //reset the counter register
- // }
- USART_ClearITPendingBit(USART1,USART_IT_IDLE);
-
- USART_ITConfig(USART1,USART_IT_IDLE,DISABLE);
- //close usart IDLE interrupt
- }
- #else
- //IRQ handle by SYSTICK + IDLE inquiry
- static uint32_t thisRcvTime = 0;
-
- if ( USART_GetITStatus( USART1 , USART_IT_RXNE ) != RESET ) {
- usartRx.endTime = thisRcvTime;
- thisRcvTime = millis();
- //update lastTime recieved a byte
- usartRx.buff[usartRx.buffHead] = USART1->DR;
-
- //interval > 10ms
- if(thisRcvTime - usartRx.endTime > 10){
- usartRx.frameHead = usartRx.buffHead;
- }else{
- // usartRx.isDeal = true;
- usartRx.frameEnd = usartRx.buffHead;
- //if interval < 10ms ,stream belong to same frame
- USART_ITConfig(USART1,USART_IT_IDLE,ENABLE);
- //start idle time detect
- }
- usartRx.buffHead = (usartRx.buffHead + 1)%USART_BUFF_SIZE;
-
- USART_ClearITPendingBit(USART1,USART_IT_RXNE);
- }
- //detect IDLE time
- if ( USART_GetITStatus( USART1 , USART_IT_IDLE ) != RESET ) {
- if(millis() - thisRcvTime > 10 ){
- USART_ITConfig(USART1,USART_IT_IDLE,DISABLE);
- //close idle interrupt for save CPU
- usartRx.isDeal = false;
- }
- USART_ClearITPendingBit(USART1,USART_IT_IDLE);
- }
- #endif
- }
然后再處理函數里頭實現一個簡單的回顯
- #if defined(USART_RECIEVE_BY_SYSTICK)
- //USART1 recieve frame by systick + RXNE
- void usart_recieve_systick_handler(void)
- {
- uint16_t i;
- if(usartRx.isDeal == false){
- USART_ITConfig(USART1,USART_IT_IDLE|USART_IT_RXNE,DISABLE);
- if(usartRx.frameHead < usartRx.frameEnd){
- // printf("%d < %d\r\n",usartRx.frameHead,usartRx.frameEnd);
- for(i=usartRx.frameHead; i<=usartRx.frameEnd; i++){
- while((USART1->SR & 0X40)==0);
- USART1->DR = usartRx.buff[i];
- }
- }else{
- // printf("%d > %d\r\n",usartRx.frameHead,usartRx.frameEnd);
- for(i=usartRx.frameHead; i<USART_BUFF_SIZE; i++){
- while((USART1->SR & 0X40)==0);
- USART1->DR = usartRx.buff[i];
- }
- for(i=0; i<usartRx.frameEnd; i++){
- while((USART1->SR & 0X40)==0);
- USART1->DR = usartRx.buff[i];
- }
- }
- USART_ITConfig(USART1,USART_IT_IDLE|USART_IT_RXNE,ENABLE);
- usartRx.isDeal = true;
- }
- }
- #endif
全部資料51hei下載地址：
ST.rar
(264.57 KB, 下載次數: 11)
2018-5-2 23:29 上傳
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