**** 2.2 Hott protocol ************************************************************************************
* Measurements being automatically transmitted are :
* - Relative altitude(cm), main vertical Speed(cm/sec) (when at least first baro sensor is present)
* - Cell voltages, lowest cell voltage (when NUMBER_OF_CELLS > 0)
* - up to 3 battery voltages (set up has to specify which voltage measurements are transmitted - E.g. VOLT_1,VOLT_2, ...)
* - Current (when Current sensor is present)
* - GPS (long, lat, speed, altitude , course, distance from home, direction from home, number of sat, type of fix) (when GPS sensor is present)
* - RPM (when RPM sensor is present)
* When you measure cell Voltages, you can get an alarm on Tx when lowest cell voltage is lower than a specified level.
* To activate this alarm, uncomment next line and specify the voltage (in milliVolt ) that trigger the alarm
* //#define CELL_UNDERVOLTAGE_WARNING 3300 // Warning threshold in mV;
*
* On top of this, you can also specify how to fill telemetry fields temperature1 and temperature2
* note : those 2 fields can only report a value from -20 up to 235; for PPM, a value of -100 will be displayed as 0 and +100 will be displayed as 200)
* Put those line(s) as comment when no measurement has to be transmitted in those telemetry field(s)
* ex:
* #define BATTERY_1_SOURCE VOLT_4 // select between VOLT_1, VOLT_2, VOLT_3 , VOLT_4, VOLT_5 , VOLT_6
* #define BATTERY_2_SOURCE VOLT_2 // select between VOLT_1, VOLT_2, VOLT_3 , VOLT_4, VOLT_5 , VOLT_6
* #define MAIN_BATTERY_SOURCE VOLT_5 // select between VOLT_1, VOLT_2, VOLT_3 , VOLT_4, VOLT_5 , VOLT_6
* #define TEMPERATURE_1_SOURCE TEST_1 // select between VOLT_1, VOLT_2, VOLT_3 , VOLT_4, VOLT_5 , VOLT_6 , TEST_1, TEST_2, TEST_3 , GLIDER_RATIO , SENSITIVITY , PPM
* #define TEMPERATURE_2_SOURCE SENSITIVITY // select between VOLT_1, VOLT_2, VOLT_3 , VOLT_4, VOLT_5 , VOLT_6 , TEST_1, TEST_2, TEST_3 , GLIDER_RATIO , SENSITIVITY , PPM