WIP - Puck.js reading CSC (cycling speed cadence) BLE sensor to replace bike computer head unit with Puck.js or (later) Pixl.js

Hi! Just sitting there monitoring a GPIO with setWatch is pretty low-power - your idea of using a vibration sensor is nice and easy. There are some Power consumption figures for Puck.js here - http://www.espruino.com/Puck.js#power-consumption

Only thing to watch out for is you want a vibration sensor that is normally not shorted. If it's shorted then just the current across the pullup resistor will probably make up the majority of your power draw!