I just got round to create a library to use an onboard timer as a quadrature encoder interface.
It is quite undocumented, but I've added an example where the Maple simulates encoder signals and all that is needed is to jumper the board's pins. I haven't been able to test it with an encoder as I haven't found one that works on 3,3V or 5V that wouldn't break my budget. Although the cheap chinese pcb encoders are terrible with bouncing and the internal filters of the chip can only do so much. :(
If anyone wants to give it a try and point out some improvements/bugs, I'd be happy to correct and upgrade.
Ideally this would be used with the HardwareTimer class, but I found that I would have to do some changes there and that would probably be an issue for compatibility.
The library is at:
Any feedback is welcome. :)