Missing messages on can bus on Gen1 FRS

[adityabln]

Hey!

I am trying to setup a can reader using arduino uno and a can shield from seed studio using MCP2515. I have tried using both the obd port and the port behind the head unit. But in both cases, I am only seeing 4 or 5 messages repeat. I am not seeing the full can traffic. I am not seeing any of the messages that are listed in this repo.

Any idea what I might be doing wrong? I am seeing can traffic, so I think my wiring should be good. But, I am only seeing 4 messages which is confusing me.

Here is a snippet of the can data I’m seeing.

ID: 0x80 DLC: 0 Data:
ID: 0xCCEC1F41 DLC: 13 Data: 0xEB 0x99 0x3D 0x32 0x47 0x21 0x47 0xB2 0x80 0x00 0x10 0x10 0xE0
ID: 0xD3B113CC DLC: 0 Data:
ID: 0x4000041E DLC: 6 Data: 0x2E 0xFD 0x6A 0x75 0x1C 0x50
ID: 0xCAE91F23 DLC: 15 Data: 0xAE 0xF6 0xCF 0x1E 0xED 0xF8 0x72 0xBF 0xF6 0x70 0x10 0xF0 0xE7 0x47 0x5F
ID: 0x80 DLC: 0 Data:

Thanks in advance,
Aditya Basina

[timurrrr]

Hi Aditya!
I haven't seen this before.
Some things to try:

• Were you trying that with ignition/engine on or off? You need it on.
• Are you using the terminating resistor? If yes, try without it; if no try with it.
• Check the baud rate.
• Have you tried an OBD-II reader to verify that the ports you're connecting to are working ok? Gen1s are known to have bad pins in the OBD-II port sometimes.

[adityabln]

Hey! Thanks for getting back to me.

I tried a few things. I am using a can shield from SeeedStudio. I was using a different can library before and I have switched to using the SeeedStudio’s can library.

Having said that, I can’t see any can traffic at all now. I don’t see the Rx LED on the can shield light up either. I am yet to try this again on the obd II port. Maybe I have an issue with the radio harness.

If that doesn’t work, I will try to setup the harness to read with an obd II reader like you suggested.

I did verify the can baud rate and it’s 500kbps.
The shield has the resistor. I would have to make some hardware changes for it. I am going to try the obd II port first.

I appreciate you getting back to me. I’ll update the issue as I find out more. If you think this ticket is not relevant to the repo, feel free to close it out.