Capacitive touch with a external perphial controller
Posted: Fri Jan 17, 2014 6:50 pm
A while back ago I was looking into creating a capacitive touch control panel for a project..
I thought I would share this because it seems most tend to want to figure out how to make a micro controller perform capacitive touch sensing with the micro controller itself..
From my reading it would seem that the highest quality capacitive touch system would be a external controller since the method of determining acquisition seems to be different than how it can be done in the main micro controller..
Or at least the method (technology ) it uses if attempted with the micro controller would take a lot of the micro controllers process time
I came across some nice chips made by Atmel which make it possible for a high quality/ reliable detection system that runs itself outside of the micro controller.
It sends a signal to the micro controller indicating a change/ detection.
It communicates with the micro controller through I2C
The chip I used is the AT42QT2120
If you are interested in learning about it, here is a link to its data sheet
http://www.atmel.com/images/doc9634.pdf
I have also attached some pictures of the first board I made for testing this chip..
this panel has 8 push buttons, 1 wheel, and a guard channel..
I created a code for this panel to allow me to see if it functioned properly and everything worked as it should..
I thought I would share this because it seems most tend to want to figure out how to make a micro controller perform capacitive touch sensing with the micro controller itself..
From my reading it would seem that the highest quality capacitive touch system would be a external controller since the method of determining acquisition seems to be different than how it can be done in the main micro controller..
Or at least the method (technology ) it uses if attempted with the micro controller would take a lot of the micro controllers process time
I came across some nice chips made by Atmel which make it possible for a high quality/ reliable detection system that runs itself outside of the micro controller.
It sends a signal to the micro controller indicating a change/ detection.
It communicates with the micro controller through I2C
The chip I used is the AT42QT2120
If you are interested in learning about it, here is a link to its data sheet
http://www.atmel.com/images/doc9634.pdf
I have also attached some pictures of the first board I made for testing this chip..
this panel has 8 push buttons, 1 wheel, and a guard channel..
I created a code for this panel to allow me to see if it functioned properly and everything worked as it should..
