note this has been written a while after the project was completed. This most likely contains a few mistakes.
Converting an old racing wheel and paddles with an old joystick plug to a standard USB interface. No drivers needed! Thanks to the easy USB-libraries of Matthew Schinkel, and the joystick pioneering of HelmPCB, this was very easy!
- The analog channels are read with a simple voltage divider using the 10 bit ADC, then they are internally linearized to 8 bit values
- The resistor values were chosen based on the stationary resistance of my particular joystick. Consider changing them with a different joystick
- It was needed to connect more than one ground of the joystick
- With QuickPIC v0.1 the usb connector is placed a bit off the board, therefor some hot glue was needed to support the connector. This is solved in v0.2
- There was no readily availabele bootloader for the 45k50, so a PICkit was directly connected to the board (QPv0.1 has swapped Vdd & GND!) Remember to disconnect the USB-serial bridge, to prevent the high programming voltage reaching the module, through the reset pin (DTR).
- The interal 16MHz oscilator is used
- Get the usb-keyboard demo of Albert Faber (blog_part3.jal), from the jallib package
- Create an appropriate HID-report-descriptor using the instructions on HelmPCB. The result is Joystk.txt . (A mirror of the software)
- Add the descriptor into the keyboard examples,
- adjust the length of the data sent
- Clear the keyboard interface class
- Change the name of the device. If somehow the devices already was installed one time under the same name, but as a keyboard, you have to uninstall for it to be recognized as a joystick
- In the main loop, construct the HID-data-package, according to your specification (from joystk.txt).
- Calibrate the joystick by running joy.cpl from your runbox (it is still there in Windows 7)
- Enjoy!
You can find all code changes made to the example in Changes.html
See the Images folder for more images of the converter.
