Reads a HMC5883L sensor to detect a magnet spinning inside a water meter. Reverses to field strength on the y axis are counted to detect water is flowing. Liters in a period are uploaded to grovestreams for graphing.
|HMC5883L Pin||Raspberry Pi Pin|
Requires the Think Bowl i2c libraries for python http://think-bowl.com/raspberry-pi/installing-the-think-bowl-i2c-libraries-for-python/ or https://github.com/quick2wire/quick2wire-python-api.git
Derived from http://seductiveequations.com/2015/11/09/water-meter.html and ported to python (thanks!).