Logitech wheels use a factory programmed version of the ST 72632 embedded processor. The chip has builtin USB controller and several A/D converters and I/O pins. You can find a datasheet of this chip from ST webpage.
Buttons are numbered from top to bottom on the table below.. So Left3 is the unused white button in the modified Momo wheel.
| Pin number | Momo function | Force GP function |
|---|---|---|
| 1 | Vdd | Vdd |
| 2 | OscOut | OscOut |
| 3 | OscIn | OscIn |
| 4 | Vss | Vss |
| 5 | Gear+ | Left1 |
| 6 | Left1 | Gear+ |
| 7 | Left2 | Gear- |
| 8 | /Reset | /Reset |
| 9 | NC | NC |
| 10 | Power enable | NC |
| 11 | Pedals1 | Pedals1 |
| 12 | Test | Test |
| 13 | Pedals2 | Pedals2 |
| 14 | LED1 | Pedals3 |
| 15 | Force control | Force control |
| 16 | LED2 | Pedals4 |
| 17 | Steering input | Steering input |
| 18 | Steering control | Steering control |
| 19 | Power enable2 | Power enable2 |
| 20 | Force control | Force control |
| 21 | Right1 | Right2 |
| 22 | Right2 | Left2 |
| 23 | Right3 | Right1 |
| 24 | Left3 | Power enable |
| 25 | NC | NC |
| 26 | NC | NC |
| 27 | NC | NC |
| 28 | Gear- | NC |
| 29 | Force control? | Force control? |
| 30 | Vssa | Vssa |
| 31 | USBDP | USBDP |
| 32 | USPDM | USBDM |
| 33 | USBVcc | USBVcc |
| 34 | Vdda | Vdda |
| Pin number | Original function | Modified function |
|---|---|---|
| 1 | Gear- | NC |
| 2 | Left3 | NC |
| 3 | Left2 | Gear- |
| 4 | Left1 | Gear+ |
| 5 | Gear+ | Left1 |
| 6 | Right3 | Right1 |
| 7 | Right2 | Left2 |
| 8 | Right1 | Right2 |
| 9 | LED1 | NC |
| 10 | LED2 | NC |
| 11 | GND | GND |
| Colour | Function |
|---|---|
| Gray | GND |
| Light blue | LED2 |
| Pink | LED1 |
| Brown | Right2 |
| White | Left2 |
| Purple | Right1 |
| Green | Left1 |
| Yellow | Gear+ |
| Red | Gear- |
| Dark blue | Right3 |
| Black | Left3 |
If you have any comments or suggestions, feel free to mail me at zuikkis@zuikk.is
– Zuikkis