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pjalocha / esp32-ogn-tracker

OGN Tracker implementation on ESP32 devices
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Vario Sensitivity #19

Open lupus78 opened 4 years ago

lupus78 commented 4 years ago

Pawel, I have figured out from the code that the pressure is only taken about twice a second to be in sync with the GPS signals, and also the slope function is on 4 values (2 sec worth of data). This results in a functioning but not very good Vario, it's slow and lags significantly.

For a good vario we would need about 5-10 measurements per second, and a configurable length of time to apply the slope function. Also the sound limits are baked in, that would also be something we could make a configuration parameter.

I'm happy to spend some time coding a better vario, but first I wanted to get feedback from you why the measurements were sync with the GPS signal.

pjalocha commented 4 years ago

The reason to sync to GPS was that the transmitted pressure altitude corresponds in time to the GPS position.

The baro code started from STM32 and BMP180 which is less precise than BMP280 and so I would read as many samples as the CPU could do over half a second and make an average. We could move to four or eight readouts per second.