TODO

* Survive the Inverter turning off at night
* Calculate the checksum to work on more than just one inverter
* Log the data to the openlog as CSV
* Add support for a RTC such as: http://www.littlebirdelectronics.com/products/Real-Time-Clock-Module.html
* Fix all the timekeeping code to survive millis() rollover
* Seperate CMS2000 code to its own library
* Log messages to one file, and data to another
* Use the 1Kb of flash to store data while SDcard is missing
* Migrate to NewSoftSerial
* Make it easier to port to another platform
* Store commands and responses in a single 'data' array
* Verify the data returned from a poll
* Design a board to fit all components on, and a container
* Have a status LED for OpenLog and for Inverter
* Don't log during handshake, log after
* Switch to allow removal of SDCard while running live
* Wiring diagrams
* Benchmark battery usage
* Add ambient light meter