Add error callback to recover from UART deadlock, use async UART

transmit

Core/Inc/cansend.h

@@ -22,7 +22,6 @@
 
 #include "main.h"
 
-void uart_printf(const char *fmt, ...);
 void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart);
 void vUARTLogger(void *argument);
 

Core/Src/canlog.c

@@ -18,7 +18,6 @@
 #include "main.h"
 /* Private includes ----------------------------------------------------------*/
 /* USER CODE BEGIN Includes */
-#include "cansend.h"
 #include "cmsis_os.h"
 #include <string.h>
 /* USER CODE END Includes */
@@ -94,7 +93,10 @@ void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
         led_task = xCAN2LedTask;
     }
 
-    if (osMessageQueuePut(queue, &message, 0U, 0U) == osOK) osThreadFlagsSet(led_task, 0x01);
+    if (osMessageQueuePut(queue, &message, 0U, 0U) == osOK)
+    {
+        osThreadFlagsSet(led_task, 0x01);
+    }
 }
 /* END HAL_CAN_RxFifo0MsgPendingCallback */
 
@@ -114,7 +116,7 @@ void vCANListener(void *argument)
   HAL_CAN_ActivateNotification(hcan, CAN_IT_RX_FIFO0_MSG_PENDING);
 
   uint32_t irqn = (hcan->Instance == CAN1) ? CAN1_RX0_IRQn : CAN2_RX0_IRQn;
-  HAL_NVIC_SetPriority(irqn, 5, 0);
+  HAL_NVIC_SetPriority(irqn, 6, 0);
   HAL_NVIC_EnableIRQ(irqn);
 
   for (;;)
@@ -131,7 +133,7 @@ void vCANListener(void *argument)
 
 /* BEGIN vLEDHeartbeat */
 /**
-  * @brief  Turn on LED when CAN traffic is detected
+  * @brief  Blink a LED in heartbeat mode when CAN traffic is detected
   * @param  argument: LED GPIO (port and pin)
   * @retval None
   */

Core/Src/cansend.c

@@ -50,16 +50,13 @@ void uart_printf(const char *fmt, ...)
   {
     if (osKernelGetState() == osKernelRunning && __get_IPSR() == 0)
     {
-      if (osSemaphoreAcquire(xUARTDMASemaphore, 100U) == osOK)
+      if (osSemaphoreAcquire(xUARTDMASemaphore, osWaitForever) == osOK)
       {
         HAL_UART_Transmit(&huart1, (uint8_t*)buf, len, HAL_MAX_DELAY);
         osSemaphoreRelease(xUARTDMASemaphore);
       }
     }
-    else
-    {
-      HAL_UART_Transmit(&huart1, (uint8_t*)buf, len, HAL_MAX_DELAY);
-    }
+    else HAL_UART_Transmit(&huart1, (uint8_t*)buf, len, HAL_MAX_DELAY);
   }
 }
 /* END uart_printf */
@@ -124,31 +121,22 @@ static int format_can_message(char *buf, uint8_t source, const CanMessage_t *mes
   */
 void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
 {
-  if (huart->Instance == USART1) osSemaphoreRelease(xUARTDMASemaphore);
+  if (huart->Instance == USART1)
+  {
+    osSemaphoreRelease(xUARTDMASemaphore);
+  }
 }
 /* END HAL_UART_TxCpltCallback */
 
 /* BEGIN HAL_UART_ErrorCallback */
-/**``MEN
-  * @brief  Handle UART errors
+/**
+  * @brief  Safely release UART semaphore inside ISR and yield task if possible.
   * @param  argument: UART handle
   * @retval None
   */
 void HAL_UART_ErrorCallback(UART_HandleTypeDef *huart)
 {
-  if (huart->Instance == USART1)
-  {
-    __HAL_UART_CLEAR_OREFLAG(huart);
-    __HAL_UART_CLEAR_FEFLAG(huart);
-    __HAL_UART_CLEAR_NEFLAG(huart);
-    __HAL_UART_CLEAR_PEFLAG(huart);
-
-    HAL_UART_DMAStop(huart);
-
-    huart->gState = HAL_UART_STATE_READY;
-
-    osSemaphoreRelease(xUARTDMASemaphore);
-  }
+  if (huart->Instance == USART1) osSemaphoreRelease(xUARTDMASemaphore);
 }
 /* END HAL_UART_ErrorCallback */
 
@@ -161,23 +149,15 @@ void HAL_UART_ErrorCallback(UART_HandleTypeDef *huart)
 void vUARTLogger(void *argument)
 {
   CanMessage_t message;
-  static char tx_buffer[45];
-
-  #ifdef DEBUG_DUMMY_FRAME
-  CanMessage_t dummy_frame = {
-    .id = 0x0CF00400,       // J1939 EEC1 ID
-    .dlc = 8,               // 8 bytes of data
-    .isExtended = 1,        // 29-bit Extended ID
-    .source = 1,            // CAN1
-    .payload = {0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF, 0x11, 0x22}
-  };
-  #endif
+  char tx_buffer[45];
 
   for (;;)
   {
-    if (osMessageQueueGet(xUARTQueue, &message, NULL, 1000U) == osOK)
+    DEBUG_PRINT("[D] Waiting for CAN traffic...\r\n");
+
+    if (osMessageQueueGet(xUARTQueue, &message, NULL, osWaitForever) == osOK)
     {
-      if (osSemaphoreAcquire(xUARTDMASemaphore, 100U) == osOK)
+      if (osSemaphoreAcquire(xUARTDMASemaphore, osWaitForever) == osOK)
       {
         int len = format_can_message(tx_buffer, message.source, &message);
 
@@ -187,9 +167,7 @@ void vUARTLogger(void *argument)
           DEBUG_PRINT("[E] HAL error, CAN frame NOT sent!\r\n");
         }
       }
-      else DEBUG_PRINT("[E] Semaphore timeout! UART might be stuck in BUSY state.\r\n");
-	}
-   	else DEBUG_PRINT("[D] Waiting for CAN traffic...\r\n");
+    }
   }
 }
 /* END vUARTLogger */

Core/Src/main.c

@@ -127,12 +127,12 @@ int main(void)
   /* USER CODE END SysInit */
 
   /* Initialize all configured peripherals */
-  MX_DMA_Init();
   MX_GPIO_Init();
-  MX_USART1_UART_Init();
+  MX_DMA_Init();
   MX_CAN1_Init();
   MX_CAN2_Init();
   MX_SDIO_SD_Init();
+  MX_USART1_UART_Init();
   /* USER CODE BEGIN 2 */
   DEBUG_PRINT("[L] Initializing CAN bus logger\r\n");
   CAN_Logger_Init(&hcan1, &hcan2);
@@ -498,22 +498,6 @@ static void MX_GPIO_Init(void)
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
   HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
 
-  //*Configure CAN1 pins : PB8, PB9 */
-  GPIO_InitStruct.Pin = GPIO_PIN_8 | GPIO_PIN_9;
-  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
-  GPIO_InitStruct.Pull = GPIO_NOPULL;
-  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
-  GPIO_InitStruct.Alternate = GPIO_AF9_CAN1;
-  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
-
-  //*Configure CAN2 pins : PB12, PB13 */
-  GPIO_InitStruct.Pin = GPIO_PIN_12 | GPIO_PIN_13;
-  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
-  GPIO_InitStruct.Pull = GPIO_NOPULL;
-  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
-  GPIO_InitStruct.Alternate = GPIO_AF9_CAN2;
-  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
-
   /* USER CODE BEGIN MX_GPIO_Init_2 */
   DEBUG_PRINT("[L] GPIO initialized\r\n");
   /* USER CODE END MX_GPIO_Init_2 */
@@ -571,8 +555,8 @@ void Error_Handler(void)
 
   while (1)
   {
-      HAL_GPIO_TogglePin(led_error.port, led_error.pin);
-      for(volatile uint32_t i = 0; i < 4000000; i++);
+    HAL_GPIO_TogglePin(led_error.port, led_error.pin);
+    HAL_Delay(250);
   }
   /* USER CODE END Error_Handler_Debug */
 }

Core/Src/stm32f4xx_it.c

@@ -41,8 +41,7 @@
 
 /* Private variables ---------------------------------------------------------*/
 /* USER CODE BEGIN PV */
-extern CAN_HandleTypeDef hcan1;
-extern CAN_HandleTypeDef hcan2;
+
 /* USER CODE END PV */
 
 /* Private function prototypes -----------------------------------------------*/
@@ -251,20 +250,4 @@ void DMA2_Stream7_IRQHandler(void)
 
 /* USER CODE BEGIN 1 */
 
-/**
-  * @brief This function handles CAN1 RX0 interrupt.
-  */
-void CAN1_RX0_IRQHandler(void)
-{
-  HAL_CAN_IRQHandler(&hcan1);
-}
-
-/**
-  * @brief This function handles CAN2 RX0 interrupt.
-  */
-void CAN2_RX0_IRQHandler(void)
-{
-  HAL_CAN_IRQHandler(&hcan2);
-}
-
 /* USER CODE END 1 */