Question
STM32F469 CAN Rx Issues
Hello, I am attempting to transmit a simple CAN message between two STM32F469I discovery boards.
I am using the official STM32F4 github as reference found here:
I can get Tx working on both boards, but the receiving of messages is not working. Am I handling the receive FIFO incorrectly? I've tried different filter settings and the loopback examples works fine.
Below is my code on both boards. Appreciate any help.
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_CAN1_Init();
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_4, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_5, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOG, GPIO_PIN_6, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOK, GPIO_PIN_3, GPIO_PIN_SET);
CAN1_filterConfig();
CAN1_start();
// Activate Notifcation
// CAN1_activateNotificaiton();
// Set Transmit
myTxMessage.StdId = SendingId;
myTxMessage.ExtId = ReceivingId;
myTxMessage.RTR = CAN_RTR_DATA;
myTxMessage.IDE = CAN_ID_STD;
myTxMessage.DLC = 2;
myTxMessage.TransmitGlobalTime = DISABLE;
TxData[0] = 0xAD;
TxData[1] = 0xAD;
ThisId = SendingId;
// ThisId = ReceivingId;
while (1) {
if(HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0) == GPIO_PIN_SET){
if(ThisId==SendingId){
// Lines for sending:
if (HAL_CAN_GetTxMailbox0FreeLevel(&hcan1) != 0) {
// Updated LED
if(payload == 2) payload=0;
LED_Switch(++payload);
sendMessageStatus = HAL_CAN_AddTxMessage(&hcan1, &myTxMessage, TxData, mailbox);
if(sendMessageStatus!=HAL_OK) {
Error_Handler_Custom(sendMessageStatus);
}
} else {
LED_Switch(3);
}
} else {
/*##-5- Start the Reception process ########################################*/
// Following lines are for receiving
if(payload == 2) payload=0;
LED_Switch(++payload);
checkFillLevelStatus = HAL_CAN_GetRxFifoFillLevel(&hcan1, CAN_RX_FIFO0);
if(checkFillLevelStatus == 0) {
/* Reception Missing */
Error_Handler_Custom(HAL_TIMEOUT);
} else {
getMessageStatus = HAL_CAN_GetRxMessage(&hcan1, CAN_RX_FIFO0, &myRxMessage, RxData);
if(getMessageStatus != HAL_OK) {
/* Reception Error */
Error_Handler_Custom(getMessageStatus);
} else if((myRxMessage.StdId != SendingId) ||
(myRxMessage.RTR != CAN_RTR_DATA) ||
(myRxMessage.IDE != CAN_ID_STD) ||
(myRxMessage.DLC != 2) ||
((RxData[0]<<8 | RxData[1]) != 0xADAD)) {
/* Rx message Error */
Error_Handler_Custom(HAL_BUSY);
} else {
LED_Switch(3);
}
}
}
HAL_Delay(200);
}
}
}
static void MX_CAN1_Init(void)
{
hcan1.Instance = CAN1;
hcan1.Init.Prescaler = 2;
hcan1.Init.Mode = CAN_MODE_NORMAL;
hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
hcan1.Init.TimeSeg1 = CAN_BS1_13TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_2TQ;
hcan1.Init.TimeTriggeredMode = DISABLE;
hcan1.Init.AutoBusOff = DISABLE;
hcan1.Init.AutoWakeUp = DISABLE;
hcan1.Init.AutoRetransmission = DISABLE;
hcan1.Init.ReceiveFifoLocked = DISABLE;
hcan1.Init.TransmitFifoPriority = DISABLE;
if (HAL_CAN_Init(&hcan1) != HAL_OK)
{
Error_Handler();
}
}
void CAN1_filterConfig(void)
{
CAN_FilterTypeDef filterConfig;
filterConfig.FilterBank = 0;
filterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
filterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
filterConfig.FilterIdHigh = 0x1fff;
filterConfig.FilterIdLow = 0xffff;
filterConfig.FilterMaskIdHigh = 0x0000;
filterConfig.FilterMaskIdLow = 0x0000;
filterConfig.FilterFIFOAssignment = CAN_RX_FIFO0;
filterConfig.FilterActivation = ENABLE;
filterConfig.SlaveStartFilterBank = 14;
can1filterConfigStatus = HAL_CAN_ConfigFilter(&hcan1, &filterConfig);
if(can1filterConfigStatus != HAL_OK)
{
Error_Handler_Custom(can1filterConfigStatus);
}
}
uint32_t HAL_CAN_GetTxMailbox0FreeLevel(CAN_HandleTypeDef *hcan)
{
uint32_t freelevel = 0U;
HAL_CAN_StateTypeDef state = hcan->State;
if ((state == HAL_CAN_STATE_READY) ||
(state == HAL_CAN_STATE_LISTENING))
{
/* Check Tx Mailbox 0 status */
if ((hcan->Instance->TSR & CAN_TSR_TME0) != 0U)
{
freelevel++;
}
}
/* Return Tx Mailboxes free level */
return freelevel;
}