Stm32 uart dma error HAL_UART_Receive_DMA(); Clear the enable bit in the DMA, clear all the flags in the DMA and the UART and then restart it the same as you did the first time. I've tested where I have the STM32 set for a baud rate of 115200kbs and Docklight set for 57600kbs. For me, I was getting an transmit error when using DMA. Calling any of the UART or DMA abort functions (HAL_UART_Abort (), HAL_UART_AbortReceive (), HAL_UART_DMAStop ()) does not reset the DMA State. Solution can be to set the tx_buffer as device type and force CPU to order the memory operations, or add __DSB () instruction before starting the DMA. DMA manages transfers of user buffer data through UART TDR register, and when completed, UART_DMATransmitCplt () is executed. Most probably or one of them report error, or you will notice something strange, like all regs zero, wrong pointers value or other issue. There are several ways how to keep manage DMA buffers with D-Cache: Disable D-Cache globally. e. Unfortunately, I misused the function. The steps mentioned in the datasheet are as shown: Write the USART_TDR register address in the DMA control register to configure it as the destination of the transfer. My use : HAL_UART_MspDeInit(); . So, for this test I just set an error flag. Solution can be to set the tx_buffer as device type and force CPU to order the memory operations, or add __DSB () instruction before starting the DMA. Therefore, DMA should be setup with peripheral flow control (UART controls DMA; set it up in stream control register), then it will probably automate this - UART will signal DMA to move received data if and only if the arrived data is OK. The call chain for HAL_UART_Receive_DMA () eventually checks the DMA State and just returns an error. When first bytes reach to UART peripheral, due to clock mismatch, it triggers frame error then stops the DMA. The issue was solved by enabling the TXE interrupt: void sas_write(char* buf, uint16_t size) { HAL_UART_Transmit_DMA(&uart_handle, buf, size) ; __HAL_UART_ENABLE_IT(&uart_handle, UART_IT_TXE) ; } How do I get the DMA to continously send out the data to the TDR for transmission? Note: this problem seems to be simliar to an unanswered question here. What I get is an HAL_UART_ERRROR_FE when I call HAL_UART_GetError (). copying the Check that clocks for both UART and DMA are running and both are initialized. But I had added the ErrorCallback function to handle the interrupt. . It is the most simple solution, but not effective one, since you can loose great part of performance. Using debugger check UART and DMA register. At this moment, the Transfer on UART lines, is not completed : only the job of DMA is completed, i. This happens more than usual when UART datarate is very high. Then in a polling routine I check for the error flag and try to enable the DMA interrupt again. qvcb xtd wjmaxf ikg vvqg evmcef xce pjycnrxa lguwanamh hnhllg