chipKIT® Development Platform

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CapTouch library for Max32 ?

Created Wed, 28 Dec 2011 11:17:04 +0000 by MGLSOFT


Wed, 28 Dec 2011 11:17:04 +0000

Is there any library capacitive touch detection? I need to make it work in my Pickit MAX32. Or is there a library for arduino capacitive touch that can be used?


Wed, 28 Dec 2011 21:36:30 +0000

The Max32 doesn't really have to hardware to support this directly. Some of the 8 and 16 bit PIC devices have the CTMU (charge time measurement unit) that is used for capacitive touch sense, but the PIC32 doesn't.

There are some external capacitive touch sense ICs available. The AD7156 is an example of one of these. We are currently working on a Pmod using this chip. Once it's done, we'll be doing a chipKIT library for the Pmod. I have not idea whether or not this would meet your need, though.

Gene Apperson Digilent


Thu, 29 Dec 2011 13:16:21 +0000

You are right, the PIC32MX use AD Converter for capacitive touch, he says in Enhanced mTouch™ Capacitive Touch Evaluation Kit User’s Guide

PIC32MX795F512H Microcontroller (U1): This provides the processing power for the touch sense applications in the PIC32MX CVD Evaluation Board. The microcontroller features 512 Kbytes of Flash program memory and 128 Kbytes RAM. The demonstration application uses an 8 MHz signal to create the 48 MHz USB clock, as well as the application’s 40 MHz clock. Crystal, Y1, and associated components are used by the microcontroller’s internal oscillator to maintain the frequency tolerances required by the USB specifications. A major difference between the PIC24F CTMU and the PIC32MX CVD Evaluation Boards is the PIC32MX CVD uses the ADC module for capacitive touch sensing, while the PIC24F CTMU uses the dedicated CTMU module.

Then I do a library to use it that way, but because they are my first Max32 Chipckit weapons, I would like if they can tell me the steps to create a library that can then be shared and used by other forum users.


Fri, 13 Jan 2012 15:54:19 +0000

That would be interesting to see on a chipKit