ESP32 CAN Decoder

ISO 15765-2 CAN frame decoder.

Discuss all things CAN, decoding, and ISO/SAE protocols for OBD.

Get the app: https://apps.apple.com/us/app/can-decod ... orm=vision
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LucanUK
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ESP32 CAN Decoder

Post by LucanUK »

This could be quite interesting for me, I had setup a ESP32 as a CAN bus reader & controller hooked into the Convenience Bus, and was able to read and send via it (could open and close windows, lock and unlock my car and a few basic things) but never moved forward with the project much... be nice to get back into it :)

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Re: ESP32 CAN Decoder

Post by jeff »

Oh that would be pretty neat! I suppose this would be the starting point for building an internet-connected vehicle via OBD?

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Re: ESP32 CAN Decoder

Post by LucanUK »

That was the general plan.. the ability to provide some of the newer automation on older cars. The problem I had was identifying the right codes.. I was basically doing trial and error.. capture, do action, stop capture.. filter known background noise from the bus and then replay back chucks at a time to replicate the action.. but it was soooo time consuming sometimes to move forward..

If I feed the app captured data will it analyze and then ID the specific ID's and chucks of data? which then I can replay back to the CAN Bus?

Attached a Youtube Video from back in 2021 of my doing a test (The ESP is only attached via USB for power as all commands are been sent over Wifi) https://www.youtube.com/watch?v=shjXxwZmx8k

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Re: ESP32 CAN Decoder

Post by jeff »

Super cool video! That must have felt like an "a-ha" moment when you got it working!

Sidecar's OBD scanner works via BTLE/WiFi OBD scanning dongles, which don't always have the best ability to monitor the CAN bus. Right now, the app's focus is primarily on monitoring read-only parameters, but I do have plans to build out some tooling for discovering, proposing, and testing new parameters on vehicles so that they can be contributed more easily to the repos at http://github.com/electricsidecar/. The GitHub account integration in Sidecar is for exactly this purpose :)

When you were monitoring the CAN bus, I'm assuming you weren't using any form of an ELM327 interface right? Just straight CAN bus monitoring?

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Re: ESP32 CAN Decoder

Post by LucanUK »

It defo was a A-ha moment when it worked! Yeah this was 2 wires straight onto the High & Low Convenience pins on the CAN Gateway after the OBD port.

IMG_4545.jpg
IMG_4545.jpg (780.73 KiB) Viewed 1894 times

yeah, when I said the App, I meant your CANDecoder App :) Wonder if that will make the tracing easier for me..

As for SideCar, I have a few questions, and maybe bugs to log from the last few days, just need to find the right place for them (think these are possible Wireless car play/Apple Maps issues, more than car specific issues)

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Re: ESP32 CAN Decoder

Post by jeff »

LucanUK wrote: Wed Oct 16, 2024 6:27 pm

yeah, when I said the App, I meant your CANDecoder App :) Wonder if that will make the tracing easier for me..

Ah! Perhaps :D CANDecoder currently supports CAN TP-Frame decoding of 11-bit and 29-bit CAN frames. If the cars you're testing on use a different protocol then I can look into adding it to the app's supported protocols :)

LucanUK wrote: Wed Oct 16, 2024 6:27 pm

As for SideCar, I have a few questions, and maybe bugs to log from the last few days, just need to find the right place for them (think these are possible Wireless car play/Apple Maps issues, more than car specific issues)

Please do share! The Sidecar forum is where we're tracking all feature/bug discussions: viewforum.php?f=12

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