I needed to make a touch keypad for a project I am doing at home. Looking around, SparkFun have one, here, that I liked the look of – except for my use, I wanted it to be simpler – it had to have up, down, left, right, and OK buttons only.
Errol GMod, the artist formerly known as Errol, over on TinyCLR forums has used the MPR121 to build a touch keypad for the CANxtra, one of the devices that GHI had on run-out sale last year. It seemed pretty easy to understand this design (ha !) so what else was I to do, but design one of my own.
So armed with my knowledge (double ha !) I took some design input from these two sources and threw something together.
My only real requirements were that it needed to have a simple button structure, to fit alongside an LCD display (a standard text-based display with 20×4 characters using an HD44780 controller chip). I decided to use a Gadgeteer standard connector so that I could use it also on a Gadgeteer compatible mainboard if I wanted to.
No fancy 3d renders, no fancy pictures, nothing. Just a set of screen capture images from a preview of the gerber files that I created.
Now the proof will be in the pudding – the gerber files for the boards were submitted to the Dorkbot PDX PCB service, and some time in the future they should arrive back here. Now for the suspenseful part, waiting for the package to arrive, who knows when, and then the joy of trying to solder that miniscule processor onto that board, and test it out ! Here’s hoping it all works !
I’ll update the post when the boards arrive and when I break out the soldering iron !
If anyone thinks they would like the original Eagle files, leave a comment. I’ll get them cleaned up and posted here when I get a chance.