=====OpenVario Protocol=====

This document describes the OpenVario communication protocol.
Communication between **sensord**  and **variod** and [[http://www.xcsoar.org| XCSoar ]] is based on NMEA sentences. NMEA is the abbreviation for "National Marine Electronics Association".

**Version 1.3**

The original definition of these sentences can be found [[https://github.com/Turbo87/openvario-protocol|here]].

Version 1.3 14.03.2016 battery voltage sentence added\\

====Specification====

**Generic definition:**

  $POV,<type>,<value>,<type>,<value>, .....*<Checksum>

The NMEA sentence always starts with $POV and ends up with a checksum and "*".
Each ''$POV'' sentence can contain multiple datapoints defined by ''type'' and ''value''. The ''type'' part is a uppercase letter describing the type and meaning of the following ''value'' according to the overview of supported types below. The ''value'' is a floating point number.
The length of the sentence is not fixed, but terminated with the usual asterisk and a two character checksum.

**Example:**

  $POV,P,+949.30,Q,-24.57*7D

===Value pair===

The following value pair are defined at the moment:

===Airspeed===

    S: true airspeed in km/h
    Example: $POV,S,123.45*05

===Pressure===    
    P: static pressure in hPa
    Example: $POV,P,1018.35*39
    
    Q: dynamic pressure in Pa
    Example: $POV,Q,23.3*04
    
    R: total pressure in hPa
    Example: $POV,R,1025.17*35

===Temperature===
    T: temperature in deg C
    Example: $POV,T,23.52*35

===Voltage===
    V: battery voltage in V
    Example: $POV,V,11.99*31        
===Vario===
    E: TE vario in m/s
    Example: $POV,E,2.15*14

===Command===
    C: Command followed by type of command and parameter if necessary
    C,<type>,<parameter>
    
    Commands are grouped in "Types":
    Vario:
      VU: Volume of external vario up by 10%
      VD: Volume of external vario down by 10%
      VM: Mute external Vario
      Example: $POV,C,VU*09 => Set up volume by 10%
      
     McCready:
       MC,<value>
       Example: $POV,C,MC,+0.5*28 => Set McCready to +0.5
       
     Wing Load:
       WL,<value>
       <value> is a factor of the additional weight added by water ballast in relation to the reference weight of the glider
       Example: $POV,C,WL,1.0*12 => No water ballast
                $POV,C,WL,1.1*13 => 10% more weight than reference weight       
     
     Bugs:
       BU,<value>
       <value> reflects the value of bugs
       Example: $POV,C,BU,1.0*1E => No Bugs
                $POV,C,WL,0.5*16 => 50% Bugs      
     
     Real Polar:
       RPO,<coff a>, <coff b>. <coff c>
       <coff x> are reflecting the coefficients of the polar including bugs and ballast
       Example: 
       
     Ideal Polar:
       IPO,<coff a>, <coff b>. <coff c>
       <coff x> are reflecting the coefficients of the ideal polar (just glider, without bugs and ballast)
       Example: 


===Checksum===

The NMEA Checksum is calculated over the NMEA string between $ and *.
The checksum is a hexadecimal number representing the XOR of all bytes

Navigate to [[projects:series_00:build:audio_vario_speed_to_fly|Audio Vario / Speed to Fly]]

=====OpenVario as Device in XCSoar =====

The Openvario Flight Computer has to be selected as Device in XCSoar. The communication between OpenVario and XCSoar is based on **TCP** at Port 4352. This must be selected in the XCSoar Device-Manager accordingly. In contrast the communication between OpenVario and Flarm (or nearly all kind of IGC-equipment like loggers) is based on a serial port. 


{{:playground:electrical_tests:xcsoar_device_manager_8583.jpg?500|}}

Edit the Device Settings in XCSoar Device Manager

{{:projects:series_00:software:edit-device-xcsoar.jpg?500|}}

XCSoar-Settings for the OpenVario

{{:projects:series_00:software:ov-nmea-xcsoar.jpg?500|}}


NMEA-Output, monitored in XCSoar Device-Manager


Navigate to [[sensord|Sensord]] 

Navigate to [[variod|Variod]] 

Back to [[overview|Software-Overview]]

Back to [[projects:series_00:build:setupguide|Setup Guide]]