The baro sensor was added before and reverted in #9858 due to #9761 so it needs testing to make sure it does not cause VSpd to break on edgetx.

I have considered compability with older tx versions.
Patch #9858 sends both vertical speed and altitude in the same frame 9.
This one sends keeps vertical speed in frame 7 and sends only the altitude in frame 9.

Support for vertical speed frame 7 was added in edgetx 2.3, support for vertical speed in frame 9 was implemented in 2.8.0.
The regression was therefore present in edgetx versions 2.3 - 2.8.0.
I have tested with edgetx 2.5.0 and the vertical speed was working as expected.

Hence i believe this improvement causes no regression in vertical speed telemetry.

@mmosca I tested this with OpenTx 2.3.14 and TBS CRSF.. Both the Vertical Speed and Altitude were present. Of which VSpd was not in the previous attempt to implement this last year.

In the proposed implementation, the same getEstimatedActualPosition function is used to get the altitude by GPS altitude by barometer. These will be the same values relative to the starting point. It seems to me that at least the GPS altitude should be given relative to sea level (i.e. from GPS data).

It would also be great to switch the bar altitude value - relative to the starting point or exclusively from the barometer at normal air pressure.

I suggested expanding the 0x09 frame of the CRSF protocol to transmit both altitudes relative to the launch point, calculated by the flight controller, and baro altitude at normal pressure. But it is not certain that my proposal will be approved, although this data is very necessary for transmission to regulatory authorities for deconfliction.

I suggested expanding the 0x09 frame of the CRSF protocol to transmit both altitudes relative to the launch point, calculated by the flight controller, and baro altitude at normal pressure. But it is not certain that my proposal will be approved, although this data is very necessary for transmission to regulatory authorities for deconfliction.

Standard temperature and pressure is used when above 18,000 in the US and Canada, as low as 3,000 in a few places in the world. If you're flying at flight level 200 and need to deconflict with jets CRSF telemetry is not the right tool for that job.

@sensei-hacker , i agree that telemetry is not the most reliable way to transfer data. But it makes no sense to transmit two identical altitudes. Moreover, the height in the 0x09 frame could be transmitted without a barometer, if there is only GPS, relative to the take-off point. And the GPS height is in the value in which it came (relative to sea level)