Standalone USB adapter for Fanatec Clubsport Shifter SQ v1.5
Built using a Teensy LC and PlatformIO
Works using software hysteresis to prevent bouncing.
If all you need is connecting your Fanatec shifter to a USB port, your best bet is to purchase the official adapter.
The main advantage of this project is to modify it to include other peripherals, extra buttons, etc
Big thanks to summivox for inspiring me to make my own adapter, and for providing much helpful details about the shifter.
You can find his work about this at
- hackaday : wiring and reverse engineering
- github : arduino code
I used an RJ12 jack (6P6C) so I could plug the cable bundled with the shifter.
Wire as following :
| RJ12 | Teensy LC |
|---|---|
| pin 1 | GND |
| pin 2 | unused |
| pin 3 | pin 14 |
| pin 4 | pin 15 |
| pin 5 | pin 16 |
| pin 6 | 3.3V |
Warning : do not use 5V if your microcontroller's pins aren't 5V tolerant !
You can of course use other pins, adjust the code as necessary.
I decided to implement software hysteresis instead of traditional debouncing. Mostly for fun, I guess...
I also tried smoothing/filtering, but it seemed unnecessary. Especialy with the ADC set to 11 bits precision (instead of the maximum 12 bits). There are unused leftovers of my attempt at smoothing, dig it up and activate it if you need/want.
I tried to auto-calibrate the X axis, with mixed results. It almost works, but as the gates of the shifter aren't evenly spaced, I had gear 4 sometimes "bleed" into gear 2.
I ended up hard-coding the values. If you need to adjust these for your shifter :
- Activate debug (uncomment this line)
- Upload the code onto your microcontroller
- Open the serial monitor
- Engage each odd gears (including 7th and reverse) and look at the X value on the serial monitor
- Take note of the average value for each gear
- Replace the values here with yours, in descending raw value, ascending gear order (reverse, 1st, 3rd, 5th, 7th). The 32 at the end is the deadband for hysteresis, leave it as is.
- Recompile and reupload
The Y axis seems very stable and consistent, it shouldn't need any adjustment.
I've included a file to customize the USB name under which the Teensy will appear. The Vendor ID and Product ID, however, are still the same.
If you are using or have been using a Teensy LC (or the same model as the one you're making your shifter adapter with), you may encounter issues because Windows is caching device names.
In this case, you can either :
- remove usb_name.c and use the default name
- create a custom Vendor/Product ID (no easy way to do this ; search PJRC forum)
- open the Windows registry and do some clean-up (at your own risk !)
Other microcontrollers will probably work too. Other Teensys (Teensies?) in particular shouldn't need any modification.
For Arduinos (Arduini?), you will need to use the Joystick library instead of the "native" support from the Teensy.
Converting to the Arduino IDE should be straightforward (rename src/main.cpp to <your_sketch>.ino and add the .h files from the include directory).
For Teensy, don't forget to set the USB type to "Serial + Keyboard + Mouse + Joystick". You can also downclock the CPU (I set my LC to 24MHz with "Fastest with LTO" optimization).
It should be possible to use the same approach for the Logitech G25/G27/G29 shifters. As far as I know, they also use 2 analog axes for the gear stick. Code will need extensive modifications though (different wiring, different number of gears, different sequential mode)...