I’ve finished a first version of the enclosure.
The components are quite simple:
- An Atmega2560 board
- an Adafruit touch screen (Nintendo digitizer)
The goal is to use the touch screen as a keyboard. I’ve created a 4 X 4 grid. It is working, except that the touch screen sends some NoteOff events even when I am still pressing on it. I’ll try to play with the pressure range to fix that.
Ok, I found a solution. First, I’ve used a multimeter as advised and replaced the resistance:
// For better pressure precision, we need to know the resistance
// between X+ and X- Use any multimeter to read it
// For the one we’re using, its 300 ohms across the X plate
TouchScreen ts = TouchScreen(XP, YP, XM, YM, 741);
Second, in Touchscreen.cpp, I’ve changed the NUMSAMPLES, from the default value (2) to 3:
#define NUMSAMPLES 3
And now it works perfectly!
xoeox 