Implement identical queue drain for CAN2 to that of CAN1

- Check queue instantly
- Use DMA to move tx_buffer to UART peripheral
- Use a semaphore to DMA is being done, to avoid moving to next loop
  iteration and overwriting tx_buffer
- HAL_UART_TxCpltCallback will release semaphore when DMA done

Core/Inc/canlog.h

@@ -45,11 +45,6 @@ typedef struct {
 } CanMessage_t;
 /* USER CODE END PTD */
 
-/**
-  * @brief  Initializes the CAN logger modules, OS threads, queues, and hardware.
-  * @param  hcan1 Pointer to the CAN1 handle
-  * @param  hcan2 Pointer to the CAN2 handle
-  */
 void CAN_Logger_Init(CAN_HandleTypeDef *hcan1, CAN_HandleTypeDef *hcan2);
 void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan);
 void vCANLoggerListen(void *argument);

Core/Src/canlog.c

@@ -31,10 +31,10 @@ extern osEventFlagsId_t xCanEventFlags;
 
 /* Private function prototypes -----------------------------------------------*/
 /* USER CODE BEGIN FunctionPrototypes */
-/* BEGIN CAN_Logger_Init */
 /**
-  * @brief  Initialize CAN bus logger.
-  * @param  argument: hcan1, hcan2
+  * @brief  Initializes the CAN logger modules, OS threads, queues, and hardware.
+  * @param  hcan1 Pointer to the CAN1 handle
+  * @param  hcan2 Pointer to the CAN2 handle
   * @retval None
   */
 void CAN_Logger_Init(CAN_HandleTypeDef *hcan1, CAN_HandleTypeDef *hcan2)
@@ -63,12 +63,11 @@ void CAN_Logger_Init(CAN_HandleTypeDef *hcan1, CAN_HandleTypeDef *hcan2)
 /* BEGIN HAL_CAN_RxFifo0MsgPendingCallback */
 /**
   * @brief  ISR for CAN message pending in FIFO0
-  * @param  argument: Can handle hcan (hcan1 or hcan2)
+  * @param  hcan: CAN handle hcan (hcan1 or hcan2)
   * @retval None
   */
 void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
 {
-    /* CODE BEGIN */
     CanMessage_t message;
     CAN_RxHeaderTypeDef rxHeader;
     uint8_t data[8];
@@ -100,7 +99,6 @@ void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
 
     if (osMessageQueuePut(queue, &message, 0U, 0U) == osOK)
     {
-        osEventFlagsSet(xCanEventFlags, flag);
         osThreadFlagsSet(led_task, 0x01);
     }
     else
@@ -121,7 +119,6 @@ void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
   */
 void vCANLoggerListen(void *argument)
 {
-  /* CODE BEGIN */
   CAN_HandleTypeDef *hcan = (CAN_HandleTypeDef*)argument;
   osMessageQueueId_t queue = (hcan->Instance == CAN1) ? xCAN1RxQueue : xCAN2RxQueue;
   CanMessage_t message;
@@ -132,7 +129,7 @@ void vCANLoggerListen(void *argument)
   {
     if (osMessageQueueGet(queue, &message, NULL, osWaitForever) == osOK)
 	{
-
+      osEventFlagsSet(xCanEventFlags, flag);
 	}
   }
 	/* CODE END */
@@ -147,7 +144,6 @@ void vCANLoggerListen(void *argument)
   */
 void vLEDHeartbeat(void *argument)
 {
-  /* CODE BEGIN */
   LED_Config *led = (LED_Config*)argument;
 
   for (;;)

Core/Src/cansend.c

@@ -20,5 +20,113 @@
 #include "cmsis_os.h"
 /* USER CODE END Includes */
 
-void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart);
-void vUARTLogger(void *argument);
+/* BEGIN format_can_message */
+/**
+  * @brief  Format CAN message for friendly reading on terminal emulators and other MCUs.
+  * @param  arguments: buffer, sourse, message
+  * @retval None
+  */
+static void format_can_message(char *buf, uint8_t source, const CanMessage_t *msg)
+{
+  const char hex[] = "0123456789ABCDEF";
+
+  buf[0] = 'C';
+  buf[1] = (source == 1) ? '1' : '2';
+  buf[2] = ':';
+
+  buf[3]  = hex[(msg->id >> 28) & 0x0F];
+  buf[4]  = hex[(msg->id >> 24) & 0x0F];
+  buf[5]  = hex[(msg->id >> 20) & 0x0F];
+  buf[6]  = hex[(msg->id >> 16) & 0x0F];
+  buf[7]  = hex[(msg->id >> 12) & 0x0F];
+  buf[8]  = hex[(msg->id >> 8) & 0x0F];
+  buf[9]  = hex[(msg->id >> 4) & 0x0F];
+  buf[10] = hex[msg->id & 0x0F];
+
+  buf[11] = ' ';
+  buf[12] = hex[(msg->dlc >> 4) & 0x0F];
+  buf[13] = hex[msg->dlc & 0x0F];
+  buf[14] = ' ';
+
+  int idx = 15;
+  for (int i = 0; i < 8; i++)
+  {
+    if (i < msg->dlc)
+    {
+      buf[idx++] = hex[(msg->payload[i] >> 4) & 0x0F];
+      buf[idx++] = hex[msg->payload[i] & 0x0F];
+    }
+    else
+    {
+      buf[idx++] = ' ';
+      buf[idx++] = ' ';
+    }
+    if (i < 7) buf[idx++] = ' ';
+  }
+
+  buf[idx++] = '\r';
+  buf[idx++] = '\n';
+}
+/* END format_can_message */
+
+/* BEGIN HAL_UART_TxCpltCallback */
+/**
+  * @brief  Safely release UART semaphore inside ISR and yield task if possible.
+  * @param  argument: UART handle
+  * @retval None
+  */
+void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
+{
+  if (huart->Instance == USART1)
+  {
+    BaseType_t xHigherPriorityTaskWoken = pdFALSE;
+    osSemaphoreReleaseFromISR(xUartDmaSem, &xHigherPriorityTaskWoken);
+    portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
+  }
+}
+/* END HAL_UART_TxCpltCallback */
+
+/* BEGIN vUARTLoggerListen */
+/**
+  * @brief  Send CAN bus traffic saved in FIFO buffer to USART1
+  * @param  argument: Not used
+  * @retval None
+  */
+void vUARTLogger(void *argument)
+{
+  CanMessage_t message;
+  char tx_buffer[45]; // converted extended frame
+  bool queues_empty;
+
+  for (;;)
+  {
+    osEventFlagsWait(xCanEventFlags, 0x03, osFlagsWaitAny, osWaitForever);
+
+    do
+    {
+      queues_empty = true;
+
+      if (osMessageQueueGet(xCAN1RxQueue, &message, NULL, 0U) == osOK)
+      {
+        format_can_message(tx_buffer, 1, &message);
+
+        HAL_UART_Transmit_DMA(&huart1, (uint8_t*)tx_buffer, 44);
+        osSemaphoreAcquire(xUartDmaSem, osWaitForever);
+
+        quesues_empty = false;
+      }
+      if (osMessageQueueGet(xCAN2RxQueue, &message, NULL, 0U) == osOK)
+      {
+        format_can_message(tx_buffer, 2, &message);
+
+        HAL_UART_Transmit_DMA(&huart1, (uint8_t*)tx_buffer, 44);
+        osSemaphoreAcquire(xUartDmaSem, osWaitForever);
+
+        queues_empty = false;
+      }
+
+    }
+    while (!queues_empty);
+  }
+}
+/* END vUARTLoggerListen */