Improved UART error recovery

- In case of an Rx error instead of stopping the complete UART, only the Rx DMA is aborted and restarted.

Inc/config.h

@@ -73,9 +73,8 @@
   #define USART_MAIN_BAUD         38400       // [bit/s] MAIN Serial Tx/Rx baud rate
 #endif
 #define SERIAL_START_FRAME        0xABCD      // [-] Start frame definition for reliable serial communication
-#define SERIAL_TIMEOUT            500         // [-] Number of wrong received data for Serial timeout detection. Depends on DELAY_IN_MAIN_LOOP
 #define SERIAL_BUFFER_SIZE        64          // [bytes] Size of Serial Rx buffer. Make sure it is always larger than the 'Feedback' structure size
-
+#define SERIAL_TIMEOUT            600         // [-] Number of wrong received data for Serial timeout detection. Depends on DELAY_IN_MAIN_LOOP
 
 /* ==================================== VALIDATE SETTINGS ==================================== */
 #if defined(SERIAL_DEBUG) && defined(SERIAL_CONTROL)

Inc/defines.h

@@ -27,8 +27,6 @@
 #include "config.h"
 #include "util.h"
 
-#define UART_DMA_CHANNEL_TX 			DMA1_Channel7
-#define UART_DMA_CHANNEL_RX 			DMA1_Channel6
 
 #if defined(PRINTF_FLOAT_SUPPORT) && defined(SERIAL_DEBUG) && defined(__GNUC__)
 	asm(".global _printf_float"); 		// this is the magic trick for printf to support float. Warning: It will increase code considerably! Better to avoid!
@@ -135,4 +133,4 @@ typedef struct {
 	int16_t 	temp;
 } MPU_Data;
 
-#endif
+#endif //  DEFINES_H 

Inc/util.h

@@ -22,23 +22,9 @@
 #define UTIL_H
 
 #include <stdint.h>
-#include "defines.h"
 
-/* general functions */
-void consoleLog(char *message);
-void get_tick_count_ms(unsigned long *count);
-void intro_demo_led(uint32_t tDelay);
-
-/* input initialization function */
-void input_init(void);
-
-/* usart read functions */
-void usart_rx_check(void);
-
-#ifdef SERIAL_DEBUG
-void usart_process_debug(uint8_t *userCommand, uint32_t len);
-#endif
 
+/* Rx Structures USART */
 #ifdef SERIAL_CONTROL
 typedef struct{
   uint16_t  start;
@@ -61,8 +47,25 @@ typedef struct{
   uint16_t  cmdLed;
   uint16_t  checksum;
 } SerialFeedback;
+#endif
+
+/* general functions */
+void consoleLog(char *message);
+void get_tick_count_ms(unsigned long *count);
+void intro_demo_led(uint32_t tDelay);
+
+/* input initialization function */
+void input_init(void);
+
+/* usart read functions */
+void usart_rx_check(void);
+#ifdef SERIAL_DEBUG
+void usart_process_debug(uint8_t *userCommand, uint32_t len);
+#endif
+#ifdef SERIAL_FEEDBACK
 void usart_process_data(SerialFeedback *Feedback_in, SerialFeedback *Feedback_out);
 #endif
+void UART_EndRxTransfer(UART_HandleTypeDef *huart);
 
 /* i2c write/read functions */
 int8_t i2c_writeBytes(uint8_t slaveAddr, uint8_t regAddr, uint8_t length, uint8_t *data);

Src/util.c

@@ -39,6 +39,7 @@ SerialSideboard Sideboard;
 #if defined(SERIAL_DEBUG) || defined(SERIAL_FEEDBACK)
 static uint8_t rx_buffer[SERIAL_BUFFER_SIZE]; 	// USART Rx DMA circular buffer
 static uint32_t rx_buffer_len = ARRAY_LEN(rx_buffer);
+static uint32_t old_pos;
 #endif
 
 #ifdef SERIAL_FEEDBACK
@@ -155,7 +156,6 @@ void input_init(void) {
 void usart_rx_check(void)
 {
 	#ifdef SERIAL_DEBUG
-	static uint32_t old_pos;
 	uint32_t pos;
 
 	pos = rx_buffer_len - __HAL_DMA_GET_COUNTER(huart2.hdmarx); 				// Calculate current position in buffer, Rx: DMA1_Channel6->CNDTR, Tx: DMA1_Channel7
@@ -170,14 +170,12 @@ void usart_rx_check(void)
         }
     }
     old_pos = pos;                              								// Updated old position
-
 	if (old_pos == rx_buffer_len) { 											// Check and manually update if we reached end of buffer
         old_pos = 0;
     }
 	#endif // SERIAL_DEBUG
 
 	#ifdef SERIAL_FEEDBACK
-	static uint32_t old_pos;
 	uint32_t pos;
 	uint8_t *ptr;	
     pos = rx_buffer_len - __HAL_DMA_GET_COUNTER(huart2.hdmarx); 				// Calculate current position in buffer, Rx: DMA1_Channel6->CNDTR, Tx: DMA1_Channel7	
@@ -247,11 +245,30 @@ void usart_process_data(SerialFeedback *Feedback_in, SerialFeedback *Feedback_ou
 void HAL_UART_ErrorCallback(UART_HandleTypeDef *uartHandle) {
 	#if defined(SERIAL_DEBUG) || defined(SERIAL_FEEDBACK)
 	if(uartHandle->Instance == USART2) {
-		HAL_UART_Receive_DMA (uartHandle, (uint8_t *)rx_buffer, sizeof(rx_buffer));
+		HAL_DMA_Abort(uartHandle->hdmarx);
+		UART_EndRxTransfer(uartHandle);
+		HAL_UART_Receive_DMA(uartHandle, (uint8_t *)rx_buffer, sizeof(rx_buffer));
+		old_pos = 0;
 	}
 	#endif
 }
 
+/**
+  * @brief  End ongoing Rx transfer on UART peripheral (following error detection or Reception completion).
+  * @param  huart: UART handle.
+  * @retval None
+  */
+void UART_EndRxTransfer(UART_HandleTypeDef *huart)
+{
+  /* Disable RXNE (Interrupt Enable) and PE (Parity Error) interrupts */
+  CLEAR_BIT(huart->Instance->CR1, (USART_CR1_RXNEIE | USART_CR1_PEIE));
+  /* Disable EIE (Frame error, noise error, overrun error) interrupts */
+  CLEAR_BIT(huart->Instance->CR3, USART_CR3_EIE);
+
+  /* At end of Rx process, restore huart->RxState to Ready */
+  huart->RxState = HAL_UART_STATE_READY;
+}
+
 /* =========================== I2C WRITE Functions =========================== */
 
 /*