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(SOLVED) STM32F103C8 UART Interrupt Flooding

Question asked by Majchrak.Peter on Feb 7, 2015
Latest reply on Apr 11, 2015 by gtenrreiro
I want to receive data from ESP8266 module after restarting it. But after restart, it starts the communication at a higher baud rate and after it's done booting it uses 9600 baud. When I have the UART peripheral enabled and receiving by using interrupts it reads the first part (9600baud) then it detects frame errors on the faster part but then when it switches to 9600baud it can't receive the data. It just fires the interrupt in a very strange way have a look. What you will see is a trace from logic analyzer. Channel 1 is the TX line of the micro. Channel 2 is the RX line and channel 3 is a pin value that changes(toggles) inside the interrupt handler.
After it begins to receive data at 9600baud again it starts to flood the micro with interrupts on every other byte that is received. To me it seems that it has not properly recovered from the frame errors. Maybe some flags were not cleared or something because before the frame errors it works normally. How can I receive the data after having frame error?
Code that initializes the UART peripheral (I am using the new STM32CubeF1 v1.0.0):
uart.Init.BaudRate = 9600;
uart.Init.HwFlowCtl = UART_HWCONTROL_NONE;
uart.Init.Mode = UART_MODE_TX_RX;
uart.Init.OverSampling = UART_OVERSAMPLING_16;
uart.Init.Parity = UART_PARITY_NONE;
uart.Init.StopBits = UART_STOPBITS_1;
uart.Init.WordLength = UART_WORDLENGTH_8B;
if (HAL_UART_Init(&uart) != HAL_OK) {

Thank you for any suggestions.

There was a code in the HAL drivers(stm32f1xx_hal_uart.c -> HAL_UART_IRQHandler()) that tells the USART to stop receiving by setting the state to "ready". I just commented out the line, like this
if (huart->ErrorCode != HAL_UART_ERROR_NONE) {
    /* Set the UART state ready to be able to start again the process */
    //huart->State = HAL_UART_STATE_READY;