PTC Baremetal / without QTouch Library

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I'm using an ATSAML21 chip.  The datasheet section on the Peripheral Touch Controller is a joke - no registers listed, and the Functional Description doesn't describe squat.  It basically says "use QTouch Composer and our crapmel generated code".

 

How bad are the dependencies from QTouch Composer emitted code?  Does it expect any of the START or ASF framework to be in place?

 

That would be problematic for me as my project is baremetal.  I'm not even sure how applicable QTouch generated code would be, since my application doesn't shoehorn directly into your typical touch-switch, slide-switch, etc.  Rather, it monitors changes in capacitance between two plates to detect when liquid flows in a tube (vs. air).  I have an AVR prototype (on an ATtiny861a) that uses custom code to sense capacitance on plain old GPIO lines attached to foil strips (no other components needed - basically it grounds the line then times how long it takes to charge up to VCC) and it works acceptably well.  I have some custom "calibration" / drift-prevention going on - mainly, I'm using the capacitance across a nearby, identical tube that's always empty, to act as a baseline (kind of like differential signaling - it gives some immunity to environmental factors/noise).  I'm porting the project, and was hoping to use the PTC to wake my MCU when something interesting happens on the sense lines (and maybe some PTC features to make my sense algorithm slightly more sophisticated).  But I need documentation on how the peripheral works.  I'm hoping the answer isn't "reverse engineer some generated code".

 

Thanks!