STM32-USART HAL库接收任意长度数据详细解析
前言：
最近在调试STM32L152 HAL库串口接收任意长度数据程序，详细解析下接收任意长度数据的方法。
硬件平台：STM32L152
软件平台：keil v5+cubeMX
函数库：HAL库
STM32L152 —USART
STM32L152 USART 的HAL库中接收函数：
HAL_StatusTypeDef HAL_UART_Receive_IT(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size)；
该函数的参数Size固定，使用时很不方便，只能接收固定长度的数据。
本文详细解析HAL库UASRT接收函数并修改成接收任意长度。PS:仅适用于接收数据结尾为换行符0x0a,若接收数据为其他格式，可根据数据的特点进行修改。
1.HAL_UART_Receive_IT(&huart1, (uint8_t *)aRxBuffer, 200);
开始接收终端，设定一个初始长度200，接收的任意字节数不大于200就行。
2.中断处理函数
void USART1_IRQHandler(void)
{
HAL_UART_IRQHandler(&huart1);
}3.在HAL_UART_IRQHandler(&huart1)的定义找到接收终端函数 ：UART_Receive_IT(huart);
void HAL_UART_IRQHandler(UART_HandleTypeDef *huart)
{
uint32_t tmp_flag = 0, tmp_it_source = 0;
tmp_flag = __HAL_UART_GET_FLAG(huart, UART_FLAG_PE);
tmp_it_source = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_PE);
/* UART parity error interrupt occurred ------------------------------------*/
if((tmp_flag != RESET) && (tmp_it_source != RESET))
{
huart->ErrorCode |= HAL_UART_ERROR_PE;
}
tmp_flag = __HAL_UART_GET_FLAG(huart, UART_FLAG_FE);
tmp_it_source = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_ERR);
/* UART frame error interrupt occurred -------------------------------------*/
if((tmp_flag != RESET) && (tmp_it_source != RESET))
{
huart->ErrorCode |= HAL_UART_ERROR_FE;
}
tmp_flag = __HAL_UART_GET_FLAG(huart, UART_FLAG_NE);
/* UART noise error interrupt occurred -------------------------------------*/
if((tmp_flag != RESET) && (tmp_it_source != RESET))
{
huart->ErrorCode |= HAL_UART_ERROR_NE;
}
tmp_flag = __HAL_UART_GET_FLAG(huart, UART_FLAG_ORE);
/* UART Over-Run interrupt occurred ----------------------------------------*/
if((tmp_flag != RESET) && (tmp_it_source != RESET))
{
huart->ErrorCode |= HAL_UART_ERROR_ORE;
}
tmp_flag = __HAL_UART_GET_FLAG(huart, UART_FLAG_RXNE);
tmp_it_source = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_RXNE);
/* UART in mode Receiver ---------------------------------------------------*/
if((tmp_flag != RESET) && (tmp_it_source != RESET))
{
UART_Receive_IT(huart);
}
tmp_flag = __HAL_UART_GET_FLAG(huart, UART_FLAG_TXE);
tmp_it_source = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_TXE);
/* UART in mode Transmitter ------------------------------------------------*/
if((tmp_flag != RESET) && (tmp_it_source != RESET))
{
UART_Transmit_IT(huart);
}
tmp_flag = __HAL_UART_GET_FLAG(huart, UART_FLAG_TC);
tmp_it_source = __HAL_UART_GET_IT_SOURCE(huart, UART_IT_TC);
/* UART in mode Transmitter end --------------------------------------------*/
if((tmp_flag != RESET) && (tmp_it_source != RESET))
{
UART_EndTransmit_IT(huart);
}
if(huart->ErrorCode != HAL_UART_ERROR_NONE)
{
/* Clear all the error flag at once */
__HAL_UART_CLEAR_PEFLAG(huart);
/* Set the UART state ready to be able to start again the process */
huart->State = HAL_UART_STATE_READY;
HAL_UART_ErrorCallback(huart);
}
}.4.接下来是修改UART_Receive_IT(huart) 函数；
u8 flag,Rx_Size;
static HAL_StatusTypeDef UART_Receive_IT(UART_HandleTypeDef *huart)
{
uint16_t* tmp;
uint32_t tmp_state = 0;
tmp_state = huart->State;
if((tmp_state == HAL_UART_STATE_BUSY_RX) || (tmp_state == HAL_UART_STATE_BUSY_TX_RX))
{
if(huart->Init.WordLength == UART_WORDLENGTH_9B)
{
tmp = (uint16_t*) huart->pRxBuffPtr;
if(huart->Init.Parity == UART_PARITY_NONE)
{
*tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x01FF);
huart->pRxBuffPtr += 2;
}
else
{
*tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x00FF);
huart->pRxBuffPtr += 1;
}
}
else
{
if(huart->Init.Parity == UART_PARITY_NONE)//本例串口为非奇偶校验
{
*huart->pRxBuffPtr++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x00FF);
if(((uint8_t)(huart->Instance->DR & (uint8_t)0x00FF))==0x0a) flag++; //当收到0x0A换行符时认为接收结束。
Rx_Size++;
}
else
{
*huart->pRxBuffPtr++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x007F);
}
}
// if(--huart->RxXferCount == 0) // 原程序根据设定的接收缓存RxXferCount减为0时认为接收结束，注释掉，修改为if(flag== 1)；
if(flag== 1)
{
flag=0;
__HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);
/* Check if a transmit process is ongoing or not */
if(huart->State == HAL_UART_STATE_BUSY_TX_RX)
{
huart->State = HAL_UART_STATE_BUSY_TX;
}
else
{
/* Disable the UART Parity Error Interrupt */
__HAL_UART_DISABLE_IT(huart, UART_IT_PE);
/* Disable the UART Error Interrupt: (Frame error, noise error, overrun error) */
__HAL_UART_DISABLE_IT(huart, UART_IT_ERR);
huart->State = HAL_UART_STATE_READY;
}
HAL_UART_RxCpltCallback(huart);
return HAL_OK;
}
return HAL_OK;
}
else
{
return HAL_BUSY;
}
}5.编写UART串口回调函数，重新开启接收中断并清标志；
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if(huart->Instance==USART1)
{
HAL_UART_Transmit(&huart3 ,(uint8_t *)aRxBuffer,Rx_Size ,200);//用串口3打印出 来接收的数据，可忽略
HAL_UART_Receive_IT(&huart1,(uint8_t *)aRxBuffer, 200);//重新开中断
for(u8 i=0;i以上修改，便可接收结尾为0x0a的任意长度的数据。但修改HAL库并不是一个好的解决方法；若别人要移植你的程序，会给别人移植程序带来困难。使用DMA方式进行串口的接收是一个较优的方法，见：传送门