关于 HAL 库中 串口的参数 疑问
请问大家 HAL库中， 串口的Timeout 参数 具体代表什么意思如何使用1. HAL_StatusTypeDef HAL_USART_Receive (USART_HandleTypeDef * husart, uint8_t * pRxData, uint16_t Size, uint32_t Timeout)
Timeout是超时限制 这个可以理解，但是 问题是 它的单位是多少？？？？
比如填个1 代表1 什么？1ms还是1 us ？
另外填0 呢？不限时，填 ffff 呢？？
看了 HAL 的手册 都没有说清楚：
本帖最后由 Paderboy 于 2016-7-8 18:06 编辑
HAL_StatusTypeDef HAL_UART_Receive(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size, uint32_t Timeout)
{
uint16_t* tmp;
uint16_t uhMask;
if((huart->State == HAL_UART_STATE_READY) || (huart->State == HAL_UART_STATE_BUSY_TX))
{
if((pData == NULL ) || (Size == 0))
{
returnHAL_ERROR;
}
/* Process Locked */
__HAL_LOCK(huart);
huart->ErrorCode = HAL_UART_ERROR_NONE;
/* Check if a non-blocking transmit process is ongoing or not */
if(huart->State == HAL_UART_STATE_BUSY_TX)
{
huart->State = HAL_UART_STATE_BUSY_TX_RX;
}
else
{
huart->State = HAL_UART_STATE_BUSY_RX;
}
huart->RxXferSize = Size;
huart->RxXferCount = Size;
/* Computation of UART mask to apply to RDR register */
UART_MASK_COMPUTATION(huart);
uhMask = huart->Mask;
/* as long as data have to be received */
while(huart->RxXferCount > 0)
{
huart->RxXferCount--;
if(UART_WaitOnFlagUntilTimeout(huart, UART_FLAG_RXNE, RESET, Timeout)!= HAL_OK)
{
return HAL_TIMEOUT;
}
if ((huart->Init.WordLength == UART_WORDLENGTH_9B) && (huart->Init.Parity == UART_PARITY_NONE))
{
tmp = (uint16_t*) pData ;
*tmp = (uint16_t)(huart->Instance->RDR & uhMask);
pData +=2;
}
else
{
*pData++ = (uint8_t)(huart->Instance->RDR & (uint8_t)uhMask);
}
}
/* Check if a non-blocking transmit Process is ongoing or not */
if(huart->State == HAL_UART_STATE_BUSY_TX_RX)
{
huart->State = HAL_UART_STATE_BUSY_TX;
}
else
{
huart->State = HAL_UART_STATE_READY;
}
/* Process Unlocked */
__HAL_UNLOCK(huart);
return HAL_OK;
}
else
{
return HAL_BUSY;
}
}HAL_StatusTypeDef UART_WaitOnFlagUntilTimeout(UART_HandleTypeDef *huart, uint32_t Flag, FlagStatus Status, uint32_t Timeout)
{
uint32_t tickstart =HAL_GetTick();
/* Wait until flag is set */
if(Status == RESET)
{
while(__HAL_UART_GET_FLAG(huart, Flag) == RESET)
{
/* Check for the Timeout */
if(Timeout != HAL_MAX_DELAY)
{
if((Timeout == 0) || ((HAL_GetTick()-tickstart) > Timeout))
{
/* Disable TXE, RXNE, PE and ERR (Frame error, noise error, overrun error) interrupts for the interrupt process */
__HAL_UART_DISABLE_IT(huart, UART_IT_TXE);
__HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);
__HAL_UART_DISABLE_IT(huart, UART_IT_PE);
__HAL_UART_DISABLE_IT(huart, UART_IT_ERR);
huart->State = HAL_UART_STATE_READY;
/* Process Unlocked */
__HAL_UNLOCK(huart);
return HAL_TIMEOUT;
}
}
}
}
else
{
while(__HAL_UART_GET_FLAG(huart, Flag) != RESET)
{
/* Check for the Timeout */
if(Timeout != HAL_MAX_DELAY)
{
if((Timeout == 0) || ((HAL_GetTick()-tickstart) > Timeout))
{
/* Disable TXE, RXNE, PE and ERR (Frame error, noise error, overrun error) interrupts for the interrupt process */
__HAL_UART_DISABLE_IT(huart, UART_IT_TXE);
__HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);
__HAL_UART_DISABLE_IT(huart, UART_IT_PE);
__HAL_UART_DISABLE_IT(huart, UART_IT_ERR);
huart->State = HAL_UART_STATE_READY;
/* Process Unlocked */
__HAL_UNLOCK(huart);
return HAL_TIMEOUT;
}
}
}
}
return HAL_OK;
}你自己再好好分析下。。 确实HAL库的说明太过于简单了。。。 还得靠你自己。。摸索。。
UART_WaitOnFlagUntilTimeout(huart, UART_FLAG_RXNE, RESET, Timeout)
HAL_GetTick();
Paderboy 发表于 2016-7-8 18:01
你自己再好好分析下。。 确实HAL库的说明太过于简单了。。。 还得靠你自己。。摸索。。
UART_ ...
谢谢你， 这个我已经找到 了 ，而且我知道
/**
* @brief uwTick_variable uwTick variable
*/
__IO uint32_t uwTick;
/**
* @brief Provides a tick value in millisecond.
* @note This function is declared as __weak to be overwritten in case of other
* implementations in user file.
* @retval tick value
*/
__weak uint32_t HAL_GetTick(void)
{
return uwTick;
}
但具体 uwTick 单位是什么呢？？？
Tick 就是ms为单位的。。 签到签到 HAL_GetTick();基于这个函数计时来比较是否超时，而HAL_GetTick()计数单位为ms，所以就是ms了。至于填多少，就得看你的波特率，接收发送数据大小大致估算下时间。 楼主问题解决了吗 eefishing 发表于 2016-7-16 23:04
楼主问题解决了吗
可以参考 楼上的！！
1ms！！！
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