In the configuration section
[mcu display]
[display]
#contrast: 239
# The contrast to set. The value may range from 0 to 256 and the
# default is 239 for non-inverted.
, the contrast value sets the brightness as well (at least for sh1106 displays). It would be useful to have a
SET_DISPLAY_CONTRAST CONTRAST=<Contrast_value>
function to allow the brightness and contrast to be set on the fly. This would allow suitable values to be set to lengthen the life of the display when it it is not displaying useful information/ act as simple screen saver. It could also be used as an attention-getter for signalling to the user.
user @NIedze has (sort of) also previously requested set-contrast-values