CAN BUS Acknowledgment error - c

Question

I am using STM32F429 CAN bus Program with TJA1041A as CAN
Transreciver.The Problem is the messages are not getting acknowledged and herewith I
am attaching the code for further reference.I am using PCAN View to see
the messages.I kindly request to check the code and tell me if there are any faults.
Code:-
int main(void)
{
RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN2, ENABLE);
// SystemInit();
GPIO_InitTypeDef GPIO_InitDef;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
GPIO_InitDef.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13;
GPIO_InitDef.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitDef.GPIO_OType = GPIO_OType_PP;
GPIO_InitDef.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitDef.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(GPIOB, &GPIO_InitDef);
/* Connect CAN pins to AF */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource12, GPIO_AF_CAN2); // CAN2_RX
GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_CAN2); // CAN2_TX
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
GPIO_InitDef.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7;
GPIO_InitDef.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitDef.GPIO_OType = GPIO_OType_PP;
GPIO_InitDef.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitDef.GPIO_Speed = GPIO_Speed_100MHz;
/* Connect PD5 and PD7 pins for CAN Transreceiver to enable and
stanby */
GPIO_Init(GPIOD, &GPIO_InitDef);
GPIO_SetBits(GPIOD, GPIO_Pin_5|GPIO_Pin_7);
RCC_ClocksTypeDef RCC_Clocks;
CAN_InitTypeDef CAN_InitStructure;
CAN_FilterInitTypeDef CAN_FilterInitStructure;
RCC_GetClocksFreq(&RCC_Clocks);
CAN_DeInit(CAN2);
CAN_StructInit(&CAN_InitStructure);
/* CAN cell init */
CAN_InitStructure.CAN_TTCM = DISABLE;
CAN_InitStructure.CAN_ABOM = DISABLE;
CAN_InitStructure.CAN_AWUM = DISABLE;
CAN_InitStructure.CAN_NART = DISABLE;
CAN_InitStructure.CAN_RFLM = DISABLE;
CAN_InitStructure.CAN_TXFP = DISABLE;
CAN_InitStructure.CAN_Mode = CAN_Mode_Normal ;
/* quanta 1+14+6 = 21, 21 * 4 = 84, 42000000 / 84 = 5000000 */
/* CAN Baudrate = 500Kbps (CAN clocked at 42 MHz) Prescale = 4 */
/* Requires a clock with integer division into APB clock */
CAN_InitStructure.CAN_SJW = CAN_SJW_1tq; // 1+6+7 = 14, 1+14+6 = 21,
1+15+5 = 21
CAN_InitStructure.CAN_BS1 = CAN_BS1_14tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_6tq;
CAN_InitStructure.CAN_Prescaler = 4; // quanta by baudrate - 125kbps
CAN_Init(CAN2, &CAN_InitStructure);
/* CAN filter init */
CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask; //
IdMask or IdList
CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_16bit; // 16
or 32
CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000; // Everything,
otherwise 11-bit in top bits
CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterFIFOAssignment = CAN_FIFO0; // Rx
CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;
//CAN_FilterInitStructure.CAN_FilterNumber = 0; // CAN1 [ 0..13]
// CAN_FilterInit(&CAN_FilterInitStructure);
CAN_FilterInitStructure.CAN_FilterNumber = 14; // CAN2 [14..27]
CAN_FilterInit(&CAN_FilterInitStructure);
CAN_ITConfig(CAN2, CAN_IT_FMP0, ENABLE);
CanTxMsg TxMessage;
// transmit */
TxMessage.StdId = 0x321;
TxMessage.ExtId = 0x00;
TxMessage.RTR = CAN_RTR_DATA;
TxMessage.IDE = CAN_ID_STD;
TxMessage.DLC = 8;
TxMessage.Data[0] = 0x02;
TxMessage.Data[1] = 0x11;
TxMessage.Data[2] = 0x11;
TxMessage.Data[3] = 0x11;
while(1)
{
uint32_t i;
int j = 0;
uint8_t TransmitMailbox = 0;
TxMessage.Data[4] = (j >> 0) & 0xFF; // Cycling
TxMessage.Data[5] = (j >> 8) & 0xFF;
TxMessage.Data[6] = (j >> 16) & 0xFF;
TxMessage.Data[7] = (j >> 24) & 0xFF;
j++;
TransmitMailbox = CAN_Transmit(CAN2, &TxMessage);
i = 0;
while((CAN_TransmitStatus(CAN2, TransmitMailbox) != CANTXOK) && (i
!= 0xFFFF)) // Wait on Transmit
{
i++;
CAN2RX();// Pump RX
}
}
}

Answer 1

This is the default behavior of any CAN bus. You need at least two CAN controllers on the bus to establish communication. If there is just one node, you will get nothing but error frames.
For debugging purposes, all CAN controllers have a "loop back" debug feature which allows them to acknowledge and listen to their own frames. You must enable this if you are alone on the bus.
Alternatively, if you have two CAN controllers in the same MCU, you can enable both of them and wire them together.

Answer 2

Probably you should enable the transeiver : It should have some voltage in input (Vbat = 12V) and Vi/o and also you need to enable the EN Pin.