Temperature offset doesn't work correctly (keeps lowering the temperature)

[danijelt]

After some more work on the issue #7 I finally assembled the board and got it to work with my unit (more work will be needed which I'll discuss back there).

I noticed a bug with temperature offset when using external temperature sensor. In cooling mode, the target temperature keeps dropping by 1 degree. For example, if I set the target temperature to 22, after some time the target temperature set by the offset function gets reflected in the HA dashboard and that new target is being used for later calculation. Resulting in temperature dropping to the minimum of 18 after a while, as the unit's ambient temperature sensor drops faster than my sensor in HA.

From what I understood in the code, the offset, if applied, shouldn't reflect in HA and it should be only tracked internally in the ESP (via auto stored = this->load_setpoint(this->s21->get_climate_mode());).

Since my modification to the code is only in the command which is fetching the temperature, I'm opening this as a separate issue.

[danijelt]

This appears to be linked with my unit sometimes returning "wrong" CRC in G9 response - lowered by 2 for some unknown reason. Pull request in #11 fixes this.