Issue with Teensy 4.1 CAN communication with MCP2551

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1

I am conducting a project to (CAN BUS) communicate with a MS Servo motor from teensy 4.1 microcontroller. I am using MCP2551 for transmitting and receiving data. The wiring diagram is as below.

Teensy with MCP2551
Teensy with MCP25511280×720 47 KB

The code I used for the communication is as below.

#include <mcp_can.h>
#include <FlexCAN_T4.h>
#include <SPI.h>

#define RX 0
#define TX 1

FlexCAN_T4<CAN1, RX_SIZE_256, TX_SIZE_16> can;

void setup()
{
  Serial.begin(115200);
  delay(100);

  pinMode(RX,INPUT);
  pinMode(TX, OUTPUT);
  
  can.begin();
  can.setBaudRate(250000);
  can.enableFIFO();
  Serial.print("CAN Started");
}

void loop()
{
  static CAN_message_t msg1; //for recieving
  static CAN_message_t msg2; //for transmitting

  while(can.read(msg1))
  {
    Serial.print("ID: ");
    Serial.print(msg1.id, HEX);
    Serial.println("Data: ");
    for(int i =0; i< msg1.len; i++)
    {
      Serial.print(msg1.buf[i], HEX);
      Serial.print(" ");
    }
    Serial.println();
  }
  
  msg2.id = 0x141;  //CAN Message ID
  msg2.len = 8;     //CAN Message Length in bytes
  msg2.buf[0] = 0x88;
  msg2.buf[1] = 0x00;
  msg2.buf[2] = 0x00;
  msg2.buf[3] = 0x00;
  msg2.buf[4] = 0x00;
  msg2.buf[5] = 0x00;
  msg2.buf[6] = 0x00;
  msg2.buf[7] = 0x00;

  msg2.buf[0] = 0xA2;
  msg2.buf[1] = 0x00;
  msg2.buf[2] = 0x00;
  msg2.buf[3] = 0x00;
  msg2.buf[4] = 0xA0;
  msg2.buf[5] = 0x8C;
  msg2.buf[6] = 0x00;
  msg2.buf[7] = 0x00;

  can.write(msg2);
  delay(1000);
 
  Serial.println("Hello");
}
/*********************************************************************************************************
  END FILE
*********************************************************************************************************/
/*
// ID: 141      DATA: 80 00 00 00 00 00 00 00 // motor off

// ID: 141      DATA: 81 00 00 00 00 00 00 00 // motor stop

// ID: 141      DATA: 88 00 00 00 00 00 00 00 // motor on

// ID: 141      DATA: A0 00 00 00 C8 00 00 00 // torque open loop(only for MS series)

// ID: 141      DATA: A1 00 00 00 64 00 00 00 // torque closed-loop(only for MG/MF series)

// ID: 141      DATA: A2 00 00 00 A0 8C 00 00 // speed closed-loop

// ID: 141      DATA: A3 00 00 00 A0 8C 00 00 // Multi position closed-loop control command 1

// ID: 141      DATA: A4 00 D0 02 A0 8C 00 00 // Multi position closed-loop control command 2

// ID: 141      DATA: A4 00 78 00 50 46 00 00 // Multi position closed-loop control command 2   speed 120dps  angle +180°

// ID: 154      DATA: A4 00 78 00 B0 B9 FF FF // Multi position closed-loop control command 2   speed 120dps  angle -180°  ID#20

// ID: 141      DATA: A5 00 00 00 50 46 00 00 // Single position closed-loop control command 1

// ID: 141      DATA: A6 00 D0 02 50 46 00 00 // Single position closed-loop control command 2

// ID: 141      DATA: A7 00 D0 02 94 11 00 00 // Incremental closed-loop control command 1

// ID: 141      DATA: 30 00 00 00 00 00 00 00 // Read PID parameter command

// ID: 141      DATA: 31 00 64 64 32 28 32 32 // Write PID parameter to RAM command

// ID: 141      DATA: 32 00 64 64 32 28 32 32 // Write PID parameter to ROM command

// ID: 141      DATA: 33 00 00 00 00 00 00 00 // Read acceleration command

// ID: 141      DATA: 34 00 00 00 B8 0B 00 00 // Write acceleration to RAM command

// ID: 141      DATA: 37 00 00 00 00 00 00 00 // Read max torque

// ID: 141      DATA: 38 00 00 00 64 00 00 00 // Write max torque to RAM

// ID: 141      DATA: 90 00 00 00 00 00 00 00 // Read encoder command

// ID: 141      DATA: 91 00 00 00 00 00 00 00 // Write encoder value as motor zero point command

// ID: 141      DATA: 19 00 00 00 00 00 00 00 // Write the current position to ROM as the zero point command of the motor

// ID: 141      DATA: 92 00 00 00 00 00 00 00 // read multi angle

// ID: 141      DATA: 94 00 00 00 00 00 00 00 // read single angle

// ID: 141      DATA: 9A 00 00 00 00 00 00 00 // read error/state 1

// ID: 141      DATA: 9B 00 00 00 00 00 00 00 // clear error

// ID: 141      DATA: 9C 00 00 00 00 00 00 00 // read state 2

// ID: 141      DATA: 9D 00 00 00 00 00 00 00 // read state 3
*/

The detailed document of the motor is uploaded below.
K-Tech -MS9025v3 Motor.pdf (6.3 MB)

However, the I could not able to transmit or receive any data until now. Could anyone please find out what mistake/s I did here?

2

CAN uses an inframe acknowledgement, you need at least one receiver and 1 transmitter.

3

Teensy 4.1 (sending commands to the motor) working as the transmitter and receiving feedback (motor speed, angle, torque, etc.). So do you recommend to use two MCP2551 chips?

Sorry, could you please be kind to explain more?

4

I can understand your frustration, the information given does not help, there is no technical information, just sales info.

Here is a link to the specification. http://esd.cs.ucr.edu/webres/can20.pdf

5

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