Setting minimum voltage to write filesystem

As per discussion on RCGroups, I've implemented a voltage check to disable flash write once the voltage drops below a critical value. This is necessary because at some voltage, it is possible to erase, but not write the flash, resulting in a corrupted file-system.

My question is, does it make sense to have this be configurable in the GUI?
For now it is implemented on the configuration page (same place as battery alarm), but I'm not sure this should be easily exposed. It may make more sense for this to be a hidden switch in the tx.ini file that can only be changed via the PC.

Another thing I was considering is to save tx settings immediately after change, rather than waiting till shutdown. This way there would be less likelyhood of losing them. For various reasons, this is harder to do for the model info, though you can force it to save in various ways.

I'm open to opinions about this

I think that no need to expose a minimum voltage setting to users. Maybe place setting in tx.ini, but why to do it if this is the fixed value for Tx? Possible it will be better to warn user with periodical signal and flashing Tx voltage value. Also, at that case battery alarm cann't be lower then minimum voltage.

For my opinion, save Tx settings will be better at exit from menus, Tx Setting and Model Setting, if any changed.

I think about trimm setting, they changing outside menus.

Yes, but you can fly a model without going back to the main screen, and nothing prevents you to even switch the tx off while being in the menu system...

Periodical check in changes and save once in 1-5 seconds.

It is actually trickier than that.
if the voltage is too low, then the flash won't erase, or write, so the filesystem won't be corrupted.
If the voltage is high enough everything works fine.

Interesting that the voltage stops reading at 3.7V. I'd have expected a value nearer to 3.0, but likely the adc is attahced in a way that prevents very low voltage readings. I'll need to experiment with it.

To eliminate this problem you can write and read dummy file, if it's OK in that case write config files.

By the way, Battery Alarm starting from 3.30V is too low. NiMH battery starting from 1.1V/cell will discharge very quickly. Will be better start Battery Alarm from 4.00V with default value 4.30V.

I set the default alarm at 4V (it was actually disabled previously...3.3 is just the minimum value allowed by the spinbox)

I created a critical level at 3.8V. It will save all settings and then lock the flash so that no further writes can happen. It will also pop up a dialog informing you of this.

Of course it has all only been tested in the simulator, but hopefully it will work as desired.