FlexCAN_T4 - FlexCAN for Teensy 4

@skpang @msadie

Oh my god... Thank you so much you two. I feel really dumb for making such a mistake!
I cant believe it was something so simple.
I was searching for this for ages and couldnt find the sollution. I was almost sure, that I had a problem with the hardware at the end and didnt even think that it was an issue with the clock settings.

I made a mistake with the termination. I am using 120Ohms on both sides so that should be fine. But I really didnt think about the clock settings beeing to HIGH so that I can not achieve slower CANFD rates.

I was sure that the clock settings I was using would work as the PEAK Bit Rate Tool was giving me timing options for 80MHz 500K nominal rate and 2M data rate and I imagined I could just use the same setting on the PEAK device as well as on the Teensy but looks like I was mistaken.
That shows that maybe I should test around with different clock settings before diving to deep into the documentation of the hardware.

Now I just need to test and see if I can achieve higher bit rates as well.
 
Trying to get comms working with a Megasquirt ECU and teensy 4.0. I get this readout when I use FlexCan sketchs. I've read on a post about a setting a transceiver enable pin, but I have found nothing that explains connections. Not a coder in any sense, and just getting into using these devices.
Teensy Output.PNG


What settings/code/connection should I be using to make this work? I'm using the RX1/TX1 pins on the teensy, connected to the SN65hVD230 transceiver.

The following test code works, I see T4.0Cantest Repeat: Read bus2, Write bus1 on the serial monitor, so I assume the board is ok.



Code: 
// -------------------------------------------------------------
// CANtest for Teensy 4.0 using CAN2 and CAN2 bus
#include <FlexCAN_T4.h>

#define debug(msg) Serial.print("["); Serial.print(__FILE__); Serial.print("::"); Serial.print(__LINE__);  Serial.print("::"); Serial.print(msg); Serial.println("]");
void debug_pause(void)
{
  Serial.print("Paused...");
  while (!Serial.available());
  while (Serial.available()) Serial.read();
  Serial.println("Restarted.");
}

FlexCAN_T4<CAN1, RX_SIZE_256, TX_SIZE_16> Can1;
FlexCAN_T4<CAN2, RX_SIZE_256, TX_SIZE_16> Can2;

static CAN_message_t msg;
static uint8_t hex[17] = "0123456789abcdef";

// -------------------------------------------------------------
static void hexDump(uint8_t dumpLen, uint8_t *bytePtr)
{
  uint8_t working;
  while( dumpLen-- ) {
    working = *bytePtr++;
    Serial.write( hex[ working>>4 ] );
    Serial.write( hex[ working&15 ] );
  }
  Serial.write('\r');
  Serial.write('\n');
}


// -------------------------------------------------------------
void setup(void)
{
  Serial.begin(115200);
  int iSerialTimeout = 1000000;
  delay(100);
  while (!Serial && (iSerialTimeout-- != 0));
  debug (F("start setup"));

  Can1.begin();
  Can2.begin();
  Can1.setBaudRate(1000000);  
  Can2.setBaudRate(1000000);

  // t4 missing msg.ext = 0;
  msg.id = 0x100;
  msg.len = 8;
  msg.flags.extended = 0;
  msg.flags.remote   = 0;
  msg.flags.overrun  = 0;
  msg.flags.reserved = 0;
  msg.buf[0] = 10;
  msg.buf[1] = 20;
  msg.buf[2] = 0;
  msg.buf[3] = 100;
  msg.buf[4] = 128;
  msg.buf[5] = 64;
  msg.buf[6] = 32;
  msg.buf[7] = 16;
  debug (F("setup complete"));
  //debug_pause();
}


// -------------------------------------------------------------
void loop(void)
{
  msg.buf[0]++;       //since you are in a loop i just incremented each time in stead of doing it 5 times[/COLOR]
  Can1.write(msg);    //you could do it your way as well[/COLOR]
  Serial.println("T4.0cantest - Repeat: Read bus2, Write bus1");
  CAN_message_t inMsg;
  if (Can2.read(inMsg)!=0)     // Changed this to if as as opposed to while - the way you had it just gets stuck since you haven't even sent a message yet[/COLOR]
  {
    Serial.print("W RD bus 2: "); hexDump(8, inMsg.buf);
  }
  delay(20);
}
 
You might try the sketch given in <this> post. Note that it works best when an RA8875 800x480 display is attached to the T4, but if you just want to read the CAN bus data, the received data displayed in the Serial Monitor can be used for this.

Hope that helps . . .

Mark J Culross
KD5RXT
 
Hello to all and @tonton81

how can i implement with Teensy4.1 UDS server like this ,
Receive request 0x18DA00F1 and
send answer with id 0x18DAF100

Also tester send with 0x18DA00F1 and teensy need answer with 0x18DAF100.
in this sample teensy accept only request from ID 0x18DAF100.

Code: 
#include <FlexCAN_T4.h>
#include <isotp_server.h>
const uint32_t canid = 0x18DAF100;
const uint32_t request = 0x020902;
uint8_t myData[] = { 0x49, 0x2, 0x1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 1, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 3, 3, 2, 4, 4, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0x5 };
isotp_server<canid, EXTENDED_ID, request, myData, sizeof(myData)> myResource;

FlexCAN_T4<CAN1, RX_SIZE_256, TX_SIZE_16> Can1;

void canSniff(const CAN_message_t &msg) {
  Serial.print("MB "); Serial.print(msg.mb);
  Serial.print(" OVERRUN: "); Serial.print(msg.flags.overrun);
  Serial.print(" LEN: "); Serial.print(msg.len);
  Serial.print(" EXT: "); Serial.print(msg.flags.extended);
  Serial.print(" TS: "); Serial.print(msg.timestamp);
  Serial.print(" ID: "); Serial.print(msg.id, HEX);
  Serial.print(" BUS: "); Serial.print(msg.bus);
  Serial.print(" Buffer: ");
  for ( uint8_t i = 0; i < msg.len; i++ ) {
    Serial.print(msg.buf[i], HEX); Serial.print(" ");
  } Serial.println();
}

void setup() {
  Serial.begin(115200); delay(400);
  Can1.begin();
  Can1.setClock(CLK_60MHz);
  Can1.setBaudRate(500000);
  Can1.setMaxMB(16);
  Can1.enableFIFO();
  Can1.enableFIFOInterrupt();
  Can1.onReceive(canSniff);
  myResource.begin();
 
  myResource.setWriteBus(&Can1); /* we write to this bus */
}

void loop() {
}

Best Regards
 
Last edited:
I'm looking for a non-iso CAN FD example. I have a Teensy 4.1 working as CAN FD on CAN3 and am to receive a 64 byte message sent by a TCAN4550. When sending a 64 byte message with the Teensy it only outputs 8 bytes even though the msg.len to 64. I'm monitoring the data with candump on a Raspberry Pi with a Waveshare 2-Channel CAN FD HAT.
 
rlr_ndh said:
I'm looking for a non-iso CAN FD example. I have a Teensy 4.1 working as CAN FD on CAN3 and am to receive a 64 byte message sent by a TCAN4550. When sending a 64 byte message with the Teensy it only outputs 8 bytes even though the msg.len to 64. I'm monitoring the data with candump on a Raspberry Pi with a Waveshare 2-Channel CAN FD HAT.
Click to expand...
Actually I found one that works for CAN FD that I haven't tested with the regular CAN: https://github.com/cburgess5294/Arduino-Teensy41/blob/main/TEENSY_4.1_CAN_TEST_2.ino
 
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