Resolved! How can you tell if HAL_UART_Transmit_DMA() function has not finished?
I have been looking for something in the structure. while ((huart1.hdmatx->State != HAL_DMA_STATE_READY) && (huart1.hdmatx->Lock != HAL_UNLOCKED))But that does not seem to work. The only other way I can think of is when you call HAL_UART_Transmit_DM...