TMS320F28379D: CAN COMMUNICATION PROBLEM F28379D

Marco,

            Did you go through the debug tips in www.ti.com/lit/SPRACE5? Most problems can be resolved by evaluating the tips I have provided. 

Please share the oscilloscope capture from the transmit side. i.e. the CANTX pin. The waveform should be  clear enough that I am able to deduce the bit duration from it. Refer to SPRACE5 for sample waveforms. That is the level of clarity I am expecting. 

Look at the value of the CANES register. It can provide you some clue on what might be going on. 

Can you share the schematics of your boards with me privately? You can do this by initiating a friendship request with me first. You can do so by choosing the "Request Friendship" option when you hover the cursor over my name. Also please share the wiring diagram of your bus. Figure 1-1. Typical CAN bus in www.ti.com/lit/SPRACU9 shows you the correct method.

The code is the next.

#include "driverlib.h"
#include "device.h"

#define TXCOUNT 100000
#define MSG_DATA_LENGTH 8
#define TX_MSG_OBJ_ID 1

volatile unsigned long i;
volatile uint32_t txMsgCount = 0;
uint16_t txMsgData[8];

void main(void)
{

Device_init();

Device_initGPIO();
GPIO_setPinConfig(DEVICE_GPIO_CFG_CANRXB);
GPIO_setPinConfig(DEVICE_GPIO_CFG_CANTXB);

CAN_initModule(CANB_BASE);

CAN_setBitRate(CANB_BASE, DEVICE_SYSCLK_FREQ, 500000, 16);

CAN_setupMessageObject(CANB_BASE, TX_MSG_OBJ_ID, 0x1,
CAN_MSG_FRAME_STD, CAN_MSG_OBJ_TYPE_TX, 0,
CAN_MSG_OBJ_NO_FLAGS, MSG_DATA_LENGTH);

txMsgData[0] = 0x01;
txMsgData[1] = 0x23;
txMsgData[2] = 0x45;
txMsgData[3] = 0x67;
txMsgData[4] = 0x89;
txMsgData[5] = 0xAB;
txMsgData[6] = 0xCD;
txMsgData[7] = 0xEF;

CAN_startModule(CANB_BASE);

while(1)

{
CAN_sendMessage(CANB_BASE, TX_MSG_OBJ_ID, MSG_DATA_LENGTH, txMsgData);

while(((HWREGH(CANB_BASE + CAN_O_ES) & CAN_ES_TXOK)) != CAN_ES_TXOK)
{
}
}

asm(" ESTOP0");
}

It does look like a valid CAN frame. However, please provide a zoomed-in waveform. I need to confirm the bit-width is 2us (since you are using 500 kbps). Also, please measure the signal at the CANRX pin of the receiver. If There is no arbitration on the bus (i.e. you only have two nodes on the bus, one being the transmitter and the other being a receiver), the waveform at the CANTX pin of the transmitter and the CANRX pin of the receiver will be exactly identical with the exception of the ACK bit in the CANRX pin of the receiver. Note that the ACK is generated by the receiver, not the transmitter. I have explained all this in SPRACE5.

I have accepted your friendship request, so go ahead and send me the schematics and the wiring diagram for your circuit. 

Hareesh, 

I connect CAN-H y CAN_L between the F28379D and LAUNCHPAD F28377S. But the signals are similar, the receiver don't generated ACK. 

The yellow line is measured on the CANTX pin of the transmitter and the blue line on the CANRX pin of the receiver. 

The bit-width is 2us.

Did you connect the grounds (GND) of the boards together?

Yes, the both GND are connected. 

Hareesh, I have CAN communication, but now I need to send float number.

change the code  in both codes but 

uint16_t txMsgData_1[8]={0x21,0x32,0x23,0x14,0x45,0x26,0x27,0x18};

to 
float txMsgData_1[8]={3.3, 4.2, 4.5, 5.4, 3.6, 7.8, 9.8,19.42 };

and 

float rxMsgData[8];

but the data is different in the  reception.