Can someone explain me what Auto and Manual mode do (what's a difference between them) and what that Prog mode do (settings)?
The code: GitHub - CasaJasmina/Telegram-Thermostat-: A smart thermostat you can control from Telegram
And the designer of the thing hasn't responded in the 2 hours since you raised the issue in Github? Why not give them 24 hours to respond?
No answer, as I expected
Looking at the code, it appears that "manual" just holds one constant temperature while "auto" sets a different temperature depending on the day of the week.
Maybe it's useful in an office that's unoccupied on the weekends and you can save a few bucks by not running the heating at full power 2 days per week?
Prog looks like it might program the auto mode, but I haven't looked at it too closely. The three relevant functions to enter each mode are in Control.ino. The display displays different things in each mode, so that's in Screen.ino.
"Off" is also a mode.
Maybe the auto times are set by hour. I didn't go too deeply into it.