====== Protocol documentation ======
This is for coordinating our development.

===== Basics =====
First two bytes contain the command. The next two bytes is the length of the data, then the rest is data.

===== Commands =====
We have a 16 bit unsigned integer for commands:

==== Human messages (0 - 9) ====

  * [0 - 9] CMD_MESSAGE_[0-9] char - Human messages. 0 is lowest priority, 9 is highest.

==== All processes ====
  * 10 CMD_ERROR int - Error occured
==== GPS reader ====
  * 5000 CMD_GPS_DATA struct gps_data - GPS data

==== Thermopile reader ==== 
  * 5500 CMD_THERMOPILE_DATA struct thermopile_data - Thermopile data

==== Flight management (6000 - 6999) ====
  * 6000 CMD_STATUS int - Status of flight has changed, one of:
    * 0 - Flight not started
    * 1 - Ascent
    * 2 - Descent
    * 3 - Descent with parachute released
    * 4 - Landed
  * 6001 CMD_PARACHUTE bool - Parachute released if size > 0, else a request to release
  * 6003 CMD_CUTDOWN bool - Glider has been cutdown if size > 0, else a request to release
  * 6005 CMD_DESIRED_HEADING double - The desired heading calculated by the flight management.
  * 6006 CMD_ALT_DROP_POSITION int - 0 - not in altitude drop, 1-4, position from north clockwise
  * 6007 CMD_FINAL_WAYPOINT waypoint_t - The final waypoint, generally the launch point

==== Roll control ====

==== Pitch control ====

==== Configuration ====
See configuration files for descriptions and categorisation.

  * 10000 CMD_CONFIG_...
to be finished