Scaling not yet clearly defined in the NMEA protocol

[Simsys]

Max Betz wrote:

• The scaling is not yet clearly defined in the NMEA protocol. Do my assumptions fit here?
  Ballast (1.00 - 1.60) <= would it make sense to simply transfer a value in KG here? What is the appropriate value range here (i.e. maximum ballast)?
• Bugs in % (0 - 30) <= In XCSOAR / Opensoar I find a setting between 0 ... 50 %. (0 == clean, 50% wet surface "double sink rate") Which value range/scaling do you recommend here?
• Crew weight is still missing I think. Would 0 ... 300kg fit?
• Switching between climb and pre-flight mode? Our front end can currently be switched manually or use the information from the sensor. Should this be coupled with XCSOAR?

[Simsys]

Some information first:

• The aircraft polar models in the front end and in XCSoar are similar but not the same. XCSoar, for example, does not recognize a pilot weight.
• The definition of the NMEA data sets was based on other existing connections. We cannot start from scratch here.
• There is currently no polar alignment between the front end and XCSoar. This is complex and currently out of scope.

In Detail:

• Ballast: The definition of ballast as a multiple of the usual take-off weight is sufficient.
• Bugs in %: We can expand it to 50%, but i think this is not necessary
• Crew weight: is not known by xcsoar, so we can't exchange it
• Switching between climb and pre-flight: I don't see any point in defining a data set here, as XCSaoar switches this automatically and intervention here may be problematic.

To summarize. I see no need for action here at present. Our goal should be to get the defined functionality up and running. This already covers the most important points.