Failsafe mechanism to restore screen brightness / backlight to usable level #6993
Description
What part of EdgeTX is the focus of this bug?
Transmitter firmware
Current Behavior
Colour LCD screen radios (in particular) have a requirement of a minimum brightness in order for the display content to be visible. As there was the possibility of the screen backlight being locked OFF, at around v2.6 (this may be the related PR #1386), the decision was made to enforce a policy whereby the minimum screen brightness could never be OFF.
This then led to quite a few issues raised asking for that capability to be restored, and to date has not been resolved. Since the underlying issue is one of "I can't see the display"... I would suggest the solution is merely one of providing a mechanism to recover the backlight to a minimum usable level.
i.e. for touch screen-only radios, a long press of more than a given time period, possibly even locked to a specific portion of the screen. And for radios with sufficient hard keys, a two key-press/hold combination. Either combination would force the backlight to be enabled, reset to minimum brightness, and any SF/GF or other automatic attempts to turn it off would be ignored for the remainder of the session.
A similar two-press/hold combination concept could be used for a hard-keys lockout option also, which was requested in another issue, to parallel the "No Touch" function.
Expected Behavior
This would allow for the screen brightness value of "OFF" to be allowable once more (as a dedicated backlight off function and/or as well as allowing the minimum set-point to be lowered), as the end user would have a recovery mechanism if they locked themselves out due to a misconfiguration, and give them the opportunity to resolve that.