Get computed average cell value from VFAS

[3djc]

Hi all,

This post follows a discussion on CF git (https://github.com/cleanflight/cleanflight/pull/1927) where basicaly a need was expressed to be able to get your average cell value based on VFAS. The rationnal for that is that on devices with only VFAS, users have to get a feel for what a low lipo is for each cell count( ie 10.x for 3s, 14.x for a 4s,..) while it is easier to have that feeling of a single cell value.

I've not been able to find a smart way of doing that with opentx 2.1, as ratio does not seem to work very well with vfas (and does not allow 0.33 or 0.25 for exemple), going through LUA match as some issues too.

Before I raise a request with opentx, does somebody have a trick to achieve that with current opentx ?

Cheers

3djc

[Kilrah]

Create a "custom" sensor and leave the IDs at 0. Set offset to 0.25. Multiply your VFAS with that. Didn't test but it should work... however it still needs adjustment for different cell count packs.

Cleanflight actually used to have "fake cell" reporting, I was for removing it due to being misleading for most and it seems they did so then.
If you want cell reporting put an FLVSS on board, it's neither that big or expensive and you gain safety for your packs.

[3djc]

Great idea, but I have a difficulty with the custom sensor. I can put whaterver offset I want, it does not seem to get 'computed', the value stays at 0, tested with companion and also the radio.

And I agree with you, I'm fighting for this not to be back in CF

3djc

[3djc]

Tried everything I could think of arround creating that 'constant' sensors, but with no luck (2.1.7). I wonder if it is not related to the update time which never happens.

3djc

[Kilrah]

Quite possibly.

[3djc]

Shall I open an issue then ?

Cheers, 3djc

[Kilrah]

No need as that should be handled by the upcoming change in how the Ratio field works.

[3djc]

fyi, as a temporary solution, we will likely send a single computed cell value using A4

Cheers 3djc