Polling CAN data

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Polling CAN data

Postby MolsonB » Sun Oct 01, 2017 10:20 pm

Hi guys, I have my own CAN setup on a Teensy board, and I can receive all the broadcasting fine (1520 base). But I can't seem to get any polling request from MS3, or if I send a Msg_Req, I don't get a Msg_Rsp back.

For example, trying to set the RTC.
I set Enable Real Time Clock to CAN, and for compatibility reasons I picked the same as JBPerf. Table is 7 and offset is 110.
The only CAN messages I receive, are just the broadcasting ones and not any MSG_REQ to send the new time.
Is there a setting I'm missing? I even enabled ADC polling and turned on a few, but no requests show up.

Reading the Can Protocol PDF, I tried to fetch the RPM, and didn't receive anything back. Not sure what I'm doing wrong.

MS3 pre-1.5.1 beta 7

*Looking into things more, do I have to get complicated and create my own Can Device under Project Properties with an .ini file?
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Re: Polling CAN data

Postby grom_e30 » Mon Oct 02, 2017 1:28 pm

no need to add a can device with an ini. is your teensy masking 29bit headers? maybe post the teensy code and a msq file for the ecu.
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Re: Polling CAN data

Postby Manu » Tue Oct 03, 2017 4:26 am

With the recent flexcan librairie, you have to set mailboxes to use extended CAN. There are posts about this at pjrc forum.
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Re: Polling CAN data

Postby MolsonB » Tue Oct 03, 2017 7:56 am

Thank you both, it looks like it was the 29bit / extended problem. I'm not using classes and sticking to the polling.

I had to add the filters in my 'Setup'.

Code: Select all
static CAN_message_t txmsg, rxmsg;

void setup(void) {


CAN_filter_t allPassFilter;

  //leave the first 4 mailboxes to use the default filter. Just change the higher ones
  for (uint8_t filterNum = 4; filterNum < 16;filterNum++){

void loop(void) {
  if (Can0.read(rxmsg))  ..........

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