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