Question
CAN protocol between 2 or more devices
Posted on September 08, 2015 at 14:59
Hi every one I want to establish a connection using CAN between two STM32F407 boards, my CAN configuration is working on same board, CAN1 to CAN2 is successful, But i am not able to send the same frame to different board, The problem is i am not able to debug 2 devices at the same time using my laptop, Please guide me on this
void CAN_Configuration(void) {
CAN_InitTypeDef CAN_InitStructure;
/* CAN register init */
CAN_DeInit(CAN1);
CAN_DeInit(CAN2);
/* CAN2 configuration */
CAN_InitStructure.CAN_TTCM = DISABLE; // Time-triggered communication mode = DISABLED
CAN_InitStructure.CAN_ABOM = DISABLE; // Automatic bus-off management mode = DISABLED
CAN_InitStructure.CAN_AWUM = DISABLE; // Automatic wake-up mode = DISABLED
CAN_InitStructure.CAN_NART = DISABLE; // Non-automatic retransmission mode = DISABLED
CAN_InitStructure.CAN_RFLM = DISABLE; // Receive FIFO locked mode = DISABLED
CAN_InitStructure.CAN_TXFP = DISABLE; // Transmit FIFO priority = DISABLED
CAN_InitStructure.CAN_Mode = CAN_Mode_Normal; // Normal CAN mode
/* quanta 1+6+7 = 14, 14 * 24 = 336, 42000000 / 336 = 125000 */
/* CAN Baudrate = 125Kbps (CAN clocked at 42 MHz) Prescale = 24 */
CAN_InitStructure.CAN_SJW = CAN_SJW_1tq; // Synchronization jump width = 1
CAN_InitStructure.CAN_BS1 = CAN_BS1_6tq; //6
CAN_InitStructure.CAN_BS2 = CAN_BS2_7tq; //7
CAN_InitStructure.CAN_Prescaler = 24; // baudrate 1Mbps
CAN_Init(CAN1, &CAN_InitStructure);
CAN_Init(CAN2, &CAN_InitStructure);
}
void CAN_FilterConfiguration(void) {
CAN_FilterInitTypeDef CAN_FilterInitStructure;
/* CAN filter configuration */
CAN_FilterInitStructure.CAN_FilterNumber = 0; // CAN 1
CAN_FilterInitStructure.CAN_FilterNumber = 14; // CAN 2
CAN_FilterInitStructure.CAN_FilterFIFOAssignment = CAN_FIFO0; // FIFO = 0
CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask; // Filter mode = identifier mask based filtering
CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_16bit;
CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000;
CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;
CAN_FilterInit(&CAN_FilterInitStructure);
}
void CAN_TxMessage(void) {
CanTxMsg TxMessage;
// transmit */
TxMessage.StdId = 0x123;
TxMessage.ExtId = 0x00;
TxMessage.RTR = CAN_RTR_DATA;
TxMessage.IDE = CAN_ID_STD;
TxMessage.DLC = 8;
TxMessage.Data[0] = * ((unsigned char *)&ADC1->DR);
TxMessage.Data[1] = ((uint32_t)&ADC1->DR >> 8);
TxMessage.Data[2] = 0xff;
TxMessage.Data[3] = 0x07;
uint8_t TransmitMailbox = 0;
volatile uint32_t i;
static int j = 0;
TxMessage.Data[4] = ADCDmaValuesc1[1];
TxMessage.Data[5] = 0x01;
TxMessage.Data[6] = 0x02;
TxMessage.Data[7] = 0x03;
j++;
TransmitMailbox = CAN_Transmit(CAN1, &TxMessage);
i = 0;
while((CAN_TransmitStatus(CAN1, TransmitMailbox) != CANTXOK) && (i != 0xFFFFFF)) // Wait on Transmit
{
i++;
}
CAN2RX(); // Pump RX
}
void CAN2RX(void)
{
CanRxMsg RxMessage;
if (CAN_MessagePending(CAN2, CAN_FIFO0))
{
/* receive */
CAN_Receive(CAN2, CAN_FIFO0, &RxMessage);
datarx[0] = RxMessage.StdId;
datarx[1] = RxMessage.DLC;
datarx[2] = RxMessage.Data[0];
datarx[3] = RxMessage.Data[1];
datarx[4] = RxMessage.Data[2];
datarx[5] = RxMessage.Data[3];
datarx[6] = RxMessage.Data[4];
datarx[7] = RxMessage.Data[5];
datarx[8] = RxMessage.Data[6];
datarx[9] = RxMessage.Data[7];
ADC_Val2 = datarx[2] | (datarx[3] << 8);
}
}