How to “reset” altitude to "0" on the GTR?

[curmudgeon]

I generally power up my electric helicopters on a 3ft high table. Then I take the helicopter to the take off spot on the ground. I would like to reset the altitude to 0 feet at the take off spot on the ground. How do I reset the altitude value to 0 feet at this take off spot?

[Pking]

My understanding is the heli will reset by itself to zero when it detects vibration when the motor starts.

So zero at every spoolup.

[HeliMLM]

Hi John,

yes, should be exactly like pking wrote: i do have the same situation (even more as starting location is a bit lower alt on the field), see spoolup log attached >> close to -2m on startup of the heli (logging starts), height jumps to 0m during spoolup of the heli (before takeoff). seems to be based on vibration level >= 3 or similar.

[franz88]

why do you need to bring to 0?
what function wants 0 meters precise?
what is your purpose after you have 0 degrees precise?
if not is accurate what could happen?

[curmudgeon]

why do you need to bring to 0?

No "need". I just want to know how to do it, if it is even possible to do it.

what function wants 0 meters precise?

I am no aware of any particular function that "wants 0 meters precise".
.

what is your purpose after you have 0 degrees precise?

No "purpose". I just want to know how to do it, if it is even possible to do it.

if not is accurate what could happen?

I would expect the altitude readings to be off by the initial altitude error reading at baseline.