I bought a G27 cheap off ebay with no idea if it would work or not. When it arrived, the motors wouldn't move, but it did detect via USB. Figuring that the drive system was bad I decided to go through the board to figure out what was wrong. That led me down a rabbit-hole, and I ended up building a full schematic for the drive system and encoder before I figured out that the Power NFET had gone bad and taken the 2 AND gates with it. Fixing that got the motors to move a little, but calibration still failed. Further debug led to figuring out that the schmitt triggers in the encoder had blown too. I have no idea what they did to this wheel...The motors test out fine. Anyhow, I bypassed the schmitts (since I didn't have any on hand) and the wheel works great now, so my $70 was well spent I guess.
Anyhow, I thought I'd share the schematic work I did so others can maybe make use of it. I did not detail every resistor and cap value, and only the wheel, encoder and power-supply circuits are mapped out.
The Kicad schematics can be found at:
https://github.com/PhracturedBlue/G27
And I've included a PDF of the schematics as well
I hope someone finds it useful some day.
Anyhow, I thought I'd share the schematic work I did so others can maybe make use of it. I did not detail every resistor and cap value, and only the wheel, encoder and power-supply circuits are mapped out.
The Kicad schematics can be found at:
https://github.com/PhracturedBlue/G27
And I've included a PDF of the schematics as well
I hope someone finds it useful some day.
