Resolved! How do you start DMA with interrupts? huart4.Instance->CR3 |= USART_CR3_DMAT; HAL_DMA_Start_IT(&hdma_uart4_tx,(uint32_t)msg, (uint32_t)&huart4.Instance->TDR,len); Works the first time, but if you change msg and len it repeats first case.
I need the callback, to clear the cb4.DMA_Active flag and update a pointer when it finishes. I cannot step through it because it starts sending data over and over as I step through it and does not call the callback. First time msg points to "12345678...
