Hello everybody:
i'm trying to implement modbus function on mcu(stm32F4)
my structure as following
i receive data from usart6 by HAL_UART_Receive_DMA function(circular mode)
it's work when just only one MCU edge. but if two mcu edge (two modbus slave), it will make some problem.
when i polling the mcu1 only, the rxbuffer from DMA is correctly(modbus-rtu query package)
when i pooling mcu1(slaveID 2) and mcu2(slaveID 4), the package will be shift or incorrect.
my DMA parameter
my question is
i reveice uart data by "HAL_UART_Receive_DMA"
how to fix the rxbuffer shifting issue
i 'm sure that the modbusPoll(master) send the correct package
/* USER CODE BEGIN 4 */
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
/* Prevent unused argument(s) compilation warning */
UNUSED(huart);
/* NOTE: This function should not be modified, when the callback is needed,
the HAL_UART_RxCpltCallback could be implemented in the user file
*/
__NOP();
if(huart==&huart6)
{
if (rxbuffer[0]==slaveID)
{
/* if slaveID match
* put rxbuffer to ModBusInHandle
*/
__NOP();
for(int i=0;i<8;i++)
osMessagePut(ModBusInHandle,rxbuffer[i], 8);
}
else
{
// if uart RX_ID no match slaveID(switch on board), reset rxbuffer
memset(rxbuffer,0, 8);
}
HAL_Delay(1);
}
// active DMA again, because DMA set normal mode
//HAL_UART_Receive_DMA(&huart6, rxbuffer, 8);
}
