1st commit with tutorial, some servo and thumbstick stuff
some fine-tuning and an attempt at reading the Adafruit 1332 1x4 keypad
initial, untested attempt at talking with the Adafruit MPL115A2 (#992) breakout board measuring temperature and pressure
now runs, but still untested against the actual breakout board
added info about & from data sheet
added simple system test
fixed formulas and added 2's complement decoding (except for c12 which seems to be positive anyway)
some more code beautification