problem with Spirit GTR (wrong) altitude telemetry

[HeliMLM]

Hello Tomas,

i just maidened my Diabolo 700 with the Spirit GTR i received yesterday (it replaced a Spirit 2 + Rex3). just tested firmware update process and loaded the backup and everything was fine after check... so no problem with that. no complaints at all for the flight performance - felt perfect from the very first moment. same as the GT did before.

but - see log attached - the altitude given by the GTR in the Diabolo is strange/wrong. even i like low flying, i was never flying at 0m and of course not below 0m - i swear the altitude is wrong after each fast climb and descend back to 2-3meters. sometimes 0, sometimes negative (after a bit of stable hover it goes to 0m).

all my Spirits are on 3.3.2r2 - the GT in another bird is showing good altitude results and auto-rescue is working as expected. the Diabolo was powered ~3-5 minutes before flying as i had to wait for another pilot to land, the heli was on the starting point in the middle of our (gras) field for almost a minute before i finally spooled up. air temp ~23-24°C, ~100m above sea level. no idea what could cause that...

[ZeXx86]

Hello,

can you show me log of the vibrations from the flight please?
If vibrations are too low, altitude measurement is going to 0, because it thinks model is not flying.

I think I know what could be wrong, so we will only need to verify this.

[HeliMLM]

Hello,

the vibrations graph was only shifted a bit down in Jeti studio (0 point was wrong) - here is the same log just with vibrations 0 point corrected. i have included the vibrations in the lower graph too to make it visible better. but yes, the Diabolo has a low vibration level, even at ~1:25 in tictocs it's only 30-35, lowest in hover is 4-5.

[HeliMLM]

i dont want to push... but any news regarding this problem, Tomas?

nb: as said, my GT on a Logo does work as expected. and i've ordere another GTR - so maybe we'll see soon if the problem is more related to the Diabolo or the GTR in general or the one GTR in my Diabolo.

[ZeXx86]

Hello,

both units should work completely identically regarding altitude measurement.
They are basically same.

Mounting position can play very big role at the model.
For the precision there is only factor that play big role - temperature.
There is temperature compensation built in the pressure sensor, but it seems differences are too big for some reason.

Interestingly from the plots it still seem as if there is older 3.3.2, not 3.3.2-r2.

[HeliMLM]

thx a lot, Tomas!

i've updated firmware directly after i received the GTR last week - 3.3.2-r2 is the only 3.3.2-version available for download in Spirit Settings (macOS) when GT/GTR is connected. so it must be 3.3.2-r2.... is there any way to see if it is 3.3.2 or 3.3.2-r2?

as you mentioned temperature... and i've noticed the unit is noticeably warming up in operation: i've (laser-)measured warming of the case of my RS and GT/GTR. both units with built in receiver are warming up more & quicker than the GT... (as the standalone Jeti Rex3 does). but it's +/- the same for RS and GTR - so i guess it is normal? (see measurement attached, measured on the right side of the Spirit "S" on top of the case)

if it makes sense i'll just update the GTR once again and do some tests as soon as possible...! (raining today & tomorrow)

Ciao
Michael

nb: placement: all my units are on platform above tail boom, all w/ connectors in front (, antenna to tail boom Y-holder).

[Spaceman]

Hi,

My heli also seems to be suffering from low vibration My altitude readings are weired at times too. Today I flew with my TDSF with 1000rmp and each time I decended into the trigger altitude of the auto resuce it increased that trigger level by about the value set in the sofware. So after 5 times it triggered at around 50 or 60m above ground. My logs are showing negative altitude values down to -46m. In the last two weeks I have done many flights and auto rescue behaved very well up until today when it played up again. This is quite anyoing. Hope there will be a fix soon.

I will add this reply also to my own post about changing auto rescue trigger values and will add the log files over there:
https://www.spirit-system.com/phpBB3/vi ... =24&t=4838

Regards,
Bernd