I dropped the idea of using pwm signals.
Instead I have found Hitec HFS-05MS which I hacked according to online tutorials and all seems to work fine.
Now I need to put all in my test flying platform and make it flaying.
Regarding autopilot swithing:
"AP channel: low values (bar going to the left) means Autopilot mode. Around 1500 (center) means stabilization mode. Hight values (1700+) means Manual control."
For auto pilot switching I plan to use "gear" switch on on my RC transmitter - easily accessible.
The thing is that switching this I have either high or low values.
Any ideas how to get the center value to have stabilization mode?
I have 7 channel RC transmitter.