Question
Combining CAN2 and USART2
Hello,
At the moment I'm working on a project using the STM32F4 discovery board that combines CAN2 and USART2. I managed to get them both working separately, but when I combine them in the same problem I get weird output on the serial monitor. When I then try my old program to only test the UART connection it works fine. Any ideas on why the combination of CAN and UART isn't working?
My code:
int main(void)
{
HAL_Init();
/* Configure the system clock to 168 MHz */
SystemClock_Config();
UART2_Configuration();
/* Infinite loop */
while (1)
{
if(CAN_Polling() == HAL_OK)
{
char Message[] = "CAN message sent.";
HAL_UART_Transmit(&UART_Handler, (uint8_t *)Message, strlen(Message), HAL_MAX_DELAY);
}
else
{
char Message[] = "CAN failed.";
HAL_UART_Transmit(&UART_Handler, (uint8_t *)Message, strlen(Message), HAL_MAX_DELAY);
}
HAL_Delay(500);
}
}
HAL_StatusTypeDef CAN_Polling(void)
{
CAN_FilterTypeDef sFilterConfig;
/*##-1- Configure the CAN peripheral #######################################*/
CanHandle.Instance = CAN2;
CanHandle.Init.TimeTriggeredMode = DISABLE;
CanHandle.Init.AutoBusOff = DISABLE;
CanHandle.Init.AutoWakeUp = DISABLE;
CanHandle.Init.AutoRetransmission = ENABLE;
CanHandle.Init.ReceiveFifoLocked = DISABLE;
CanHandle.Init.TransmitFifoPriority = DISABLE;
CanHandle.Init.Mode = CAN_MODE_NORMAL;
CanHandle.Init.SyncJumpWidth = CAN_SJW_1TQ;
CanHandle.Init.TimeSeg1 = CAN_BS1_4TQ;
CanHandle.Init.TimeSeg2 = CAN_BS2_2TQ;
CanHandle.Init.Prescaler = 6;
if(HAL_CAN_Init(&CanHandle) != HAL_OK)
{
/* Initialization Error */
Error_Handler();
}
/*##-2- Configure the CAN Filter ###########################################*/
sFilterConfig.FilterBank = 15;
sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
sFilterConfig.FilterIdHigh = 0x0000;
sFilterConfig.FilterIdLow = 0x0000;
sFilterConfig.FilterMaskIdHigh = 0x0000;
sFilterConfig.FilterMaskIdLow = 0x0000;
sFilterConfig.FilterFIFOAssignment = CAN_RX_FIFO0;
sFilterConfig.FilterActivation = ENABLE;
sFilterConfig.SlaveStartFilterBank = 14;
if(HAL_CAN_ConfigFilter(&CanHandle, &sFilterConfig) != HAL_OK)
{
/* Filter configuration Error */
Error_Handler();
}
/*##-3- Start the CAN peripheral ###########################################*/
if (HAL_CAN_Start(&CanHandle) != HAL_OK)
{
/* Start Error */
Error_Handler();
}
/*##-4- Start the Transmission process #####################################*/
TxHeader.StdId = 0x11;
TxHeader.RTR = CAN_RTR_DATA;
TxHeader.IDE = CAN_ID_STD;
TxHeader.DLC = 2;
TxHeader.TransmitGlobalTime = DISABLE;
TxData[0] = 0xCA;
TxData[1] = 0xFE;
/* Request transmission */
if(HAL_CAN_AddTxMessage(&CanHandle, &TxHeader, TxData, &TxMailbox) != HAL_OK)
{
/* Transmission request Error */
Error_Handler();
}
/* Wait transmission complete */
while(HAL_CAN_GetTxMailboxesFreeLevel(&CanHandle) != 3) {
HAL_Delay(50);
}
if (HAL_CAN_ActivateNotification(&CanHandle, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
{
/* Notification Error */
Error_Handler();
}
return HAL_OK; /* Test Passed */
}
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
/* Get RX message */
if (HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &RxHeader, RxData) != HAL_OK)
{
/* Reception Error */
Error_Handler();
}
char Message[] = "CAN received.";
HAL_UART_Transmit(&UART_Handler, (uint8_t *)Message, strlen(Message), HAL_MAX_DELAY);
}
void UART2_Configuration(void){
__HAL_RCC_GPIOA_CLK_ENABLE(); //Enable clock to PORTA - UART2 pins PA2 and PA3
__HAL_RCC_USART2_CLK_ENABLE(); // Enable clock to UART2 module
GPIO_InitTypeDef UART2_GPIO_Handler; // Create GPIO_InitTypeDef struct instance
UART2_GPIO_Handler.Pin = GPIO_PIN_2 | GPIO_PIN_3;
UART2_GPIO_Handler.Mode = GPIO_MODE_AF_PP;
UART2_GPIO_Handler.Pull = GPIO_PULLUP;
UART2_GPIO_Handler.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
UART2_GPIO_Handler.Alternate = GPIO_AF7_USART2;
HAL_GPIO_Init(GPIOA, &UART2_GPIO_Handler);
//UART configuration
UART_Handler.Instance = USART2;
UART_Handler.Init.BaudRate = 115200;
UART_Handler.Init.Mode = UART_MODE_TX_RX;
UART_Handler.Init.WordLength = UART_WORDLENGTH_8B;
UART_Handler.Init.StopBits = UART_STOPBITS_1;
UART_Handler.Init.OverSampling = UART_OVERSAMPLING_16;
HAL_UART_Init(&UART_Handler);
}