Use firmata library where possible

[jeroendoggen]

Use the Firmata library as proposed by
HenkVanBoeijen on the Arduino forum (to avoid NIH...)
http://forum.arduino.cc/index.php?topic=195224.msg1469385#msg1469385

Firmata source:
https://github.com/arduino/Arduino/tree/master/libraries/Firmata

How?

• subclassing Firmata class? (how? https://github.com/jeroendoggen/Arduino-serial-messaging/blob/4d24823782e6c6f090e5350d261794abc49e67ad/Documentation/class_messaging__inherit__graph.png)
• or something like this? (I would prefer 'clean' & empty .ino files) https://github.com/arduino/Arduino/tree/master/libraries/Firmata/examples/I2CFirmata