Posted on October 26, 2016 at 14:08Hello ColdWeather and clive1
many thanks for your explanations. Now I have been able to get the communication running with very short interrupt times :)
My implementation still lacks elegance, so to say. Here's what I do:
When sending data, I use this function because it offers a bit of convenience:
halStatus = HAL_UART_Transmit_DMA(&huart3, (uint8_t*) buffer, size);
One (now unwanted part) of the convenience is, that the
usart->XferCpltCallback is set to a default value. After your
explanation, I don't want the default. So what I do when the DMA_IT_TC
asserts, is this:
void DMA1_Channel2_IRQHandler( void )
{
hdma_usart3_tx.XferCpltCallback = 0;
//hdma_usart3_tx.XferErrorCallback= 0;
//hdma_usart3_tx.XferHalfCpltCallback = 0;
HAL_DMA_IRQHandler(&hdma_usart3_tx);
}
The callback won't be called if it is 0. But this is kind of ugly. The
alternative would be to use HAL_DMA_Start_IT() directly, but there's
so much glue that HAL_UART_Transmit_DMA has already implemented...
UART_IT_TC is then handled in USART3_IRQHandler.
This works perfectly now. But do you have a suggestion how to remove
the callbacks more nicely?
cu
Markus
