May 23, 2011 AT 12:59 pm

Capacitive Touch PCB Keypad

Futz writes:

I designed a keypad board for the Freescale MPR121 Capacitive Touch Sensor Controller chip and received it in my latest batch of boards from dorkbotpdx.org. I’m really happy with this one. The MPR121 is really easy to use and, though it has tons of internal adjustments and controls to suit almost any sensing job, works perfectly with all default settings for my little board.

This board was pretty tough to design in Eagle. The touchpads and the traces to them have to be laid out just so or they won’t work well. The autorouter completely refused to do anything with this board no matter what I tried, so I ended up hand routing everything. And even that was very difficult. But in the end it was worth it. It looks great, and works just as well.

Cool! Looks good in purple too!


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