DIY CAN bus reader for RaceChrono

[Ronac]

Do you have any plans to make and sell these? I’d be more than happy to buy one off of you instead of making one myself and failing haha.

[timurrrr]

Originally Posted by Ronac

Do you have any plans to make and sell these? I’d be more than happy to buy one off of you instead of making one myself and failing haha.

Realistically, not anytime soon.
I already don't have enough time (or energy!) to do everything I want to do on weekends.
On weekdays I have a paid job.

The only way I could possibly justify working on something like this for money
is if it could offset taking a day or two of unpaid leave.
Given the low volume, the resultant price tag for a product I'd consider
high enough quality to charge money for would be way too high.
(That being said, if anyone has a business proposal, DM me)

The goal these GitHub projects is to provide a foundations for others to use for their own tinkering.
If you can't make a DIY data reader yourself, you might know a friend who already has
some Arduino / electronics experience to help you.

[bfitzy]

Hey timurrrr,

After some time tinkering around I finally built this device and got it working via the OBD2 pins 6 and 14. It's freaking awesome! Since I've got it paired with RaceChrono, the device has been working well. I'm now in the process of creating a harness to connect to the CAN Bus access point behind the infotainment.

I have a couple questions though now that I've gotten this far.

1) I saw that you posted a TODO to get fuel remaining working on your GitHub readme. Doing some digging, I saw that you also posted in a RaceChrono forum showing the fuel remaining PID and equation. I can't seem to get this to work. I know the PID is 0x2129 or 8489 base ten as shown in RaceChrono. The equation I'm using is the same as you mentioned "A * 0.5". Any ideas? I can see that 0x2129 shows up in the received PIDs when looking at the serial monitor with a laptop connected, but no dice with RaceChrono. No data seems to be received for it. Every other data field seems to be working.

2) Is it required to use a 16MHz chip or will the 8MHz chip work fine? I understand that the clock will run half as slow and there's no reason not to run a 16MHz chip. I'm just frankly horrible at soldering and kept mucking up MCP2515 boards lol.

Thanks again!
Brad

[timurrrr]

Originally Posted by bfitzy

After some time tinkering around I finally built this device and got it working via the OBD2 pins 6 and 14. It's freaking awesome!

Posts like this make my heart feel warm! Thank you for sharing.

Originally Posted by bfitzy

I have a couple questions though now that I've gotten this far.

1) I saw that you posted a TODO to get fuel remaining working on your GitHub readme. Doing some digging, I saw that you also posted in a RaceChrono forum showing the fuel remaining PID and equation. I can't seem to get this to work. I know the PID is 0x2129 or 8489 base ten as shown in RaceChrono. The equation I'm using is the same as you mentioned "A * 0.5". Any ideas? I can see that 0x2129 shows up in the received PIDs when looking at the serial monitor with a laptop connected, but no dice with RaceChrono. No data seems to be received for it. Every other data field seems to be working

0x2129 is an OBD-II PID, not a CAN ID.
RaceChrono adds to this confusion by (incorrectly?) referring to CAN IDs as "PID" in the equation editor UI.

I have a local branch with changes that allow sending OBD-II requests from the board. I need to clean it up a bit before I can push it to GitHub. IIRC you're one of the first one (if not the first) to ask for OBD requests

That is a benefit of this DIY project over off-the-shelf solutions such as OBDLink MX+ which only supports operating in one mode (OBD-II or CAN) at a time.

Originally Posted by bfitzy

2) Is it required to use a 16MHz chip or will the 8MHz chip work fine? I understand that the clock will run half as slow and there's no reason not to run a 16MHz chip. I'm just frankly horrible at soldering and kept mucking up MCP2515 boards lol.

Try it with 8 MHz and let me know how it goes!
You'll need to update the QUARTZ_CLOCK_FREQUENCY constant in the code.

I switched to 16 MHz quartz early on because I had some connection reliability issues. It later turned out that those were caused by using unregulated USB power on Vin of the MCP, so it is very much possible that 8 MHz quartz is sufficient.
This will save some cost, and definitely simplify the project for future DIYers!

[bfitzy]

I just completed building the final product nicely hidden away behind the passenger side glove box area. I have the breadboard double sided taped down and seems like it will hold well. I do not have access to a 3D printer, but making a nice enclosure would be the final step. I can not wait for my next local track event to test this out for real!

I'll be following the GitHub for future updates because fuel remaining would be an awesome data point to have! The use case is endurance racing. I personally would not get much use out of it but a friend of mine races his fleet of 86 race cars in lucky dog events. Having this information available would be much easier to gauge when a splash is needed.

Lastly, turns out 8MHz quartz is sufficient and works just as well as the 16MHz example.


Cheers,
Brad

[timurrrr]

Originally Posted by Ronac

Do you have any plans to make and sell these? I’d be more than happy to buy one off of you instead of making one myself and failing haha.

This product + OBDLink MX+ might solve most of your needs.
I haven't personally tested it, but an approach like this should work.

[Th0masL]

Hey !

Thanks for this nice DIY project.

I have some experience in basic electronics, and I work in IT so I have some programming experience too, so that could be useful.

I will very likely give a shot to your tutorial for the DIY reader on the connector behind the head unit.

One of my main interest, in addition to the fun of having a nice DIY project like that, is to try to implement a Door Autolock functionality, which we know is already doable due to projects like the Trac-box, or some ODB devices that require to connect on the OBD port.

I don't want to pay $200+ for the Door Autolock functionality, and I my OBD port is already taken by my OBDLink MX+, so I will try to find a way to achieve a similar result using the connector behind the head unit.

[oddrelic]

What a great find this thread is. anyway

Ive been kicking around the idea of having physical gauges on my sim racing rig and there are some examples online and videos on youtube. Ive placed an order for some Arduino's and MCP2515 boards. Figuring i would have to sniff the bus on my 86 for a bit to find out how to control the gauge cluster outside of the car.

I don't have a lot to contribute at this point, but would like to.



here are some of the video's Ive been using to get started with CanBus comms, He goes way out of scope but its nice to see that data that can be pulled.

Part 1

Part 2

Part 3


I hope to have some data for you in the future.

[Joon525]

Originally Posted by timurrrr

...solutions such as OBDLink MX+ which only supports operating in one mode (OBD-II or CAN) at a time.

@timurrrr
How does the OBDLink MX+ get configured to run in OBD2 mode vs running in CAN mode?

I just got one and plan on having the following

1. OBD2 splitter
2. OBD2 gauge on one end (oil temp, coolant temp, rpm, speed)
3. ODBLink MX+ on the other
4. RaceChrono linked up to the OBDLink MX+ but only through CAN (oil temp, coolant temp, speed, rpm, throttle position, brake position)

If I configure RaceChrono only with the CAN ID's you mentioned on GitHub is that considered putting the OBDLink MX+ in CAN mode? I looked through the OBDLink MX+'s documentation but couldn't find any mention of "modes" anywhere.

BTW thanks for the work on this project. I'm going to take a crack at building one for a friend's Gen 2 after I get my own situation sorted.

[timurrrr]

Originally Posted by Joon525

How does the OBDLink MX+ get configured to run in OBD2 mode vs running in CAN mode?

In RaceChrono "Settings", you add your OBDLink MX+ either in the "OBD-II readers" section, or in the "Other devices" section with the "OBDLink LX/MX/MX+ Bluetooth (CAN-bus)" type.

[Joon525]

Originally Posted by timurrrr

In RaceChrono "Settings", you add your OBDLink MX+ either in the "OBD-II readers" section, or in the "Other devices" section with the "OBDLink LX/MX/MX+ Bluetooth (CAN-bus)" type.

Thank you, I saw that in the settings but since it didn't explicitly say "mode" I wanted to double check that there wasn't something I had to do with the OBDLink MX+ itself.

[wizzo]

I have a 22 BRZ and picked up an ANSIX Auto Can Adaptor as a solution to the Gen 2 OBD port. Which OBD tool would be required to run Race Chrono?

https://ansixauto.com/2022-brz-gt86-can-adapter/