A bit more I have done now, Part1 is so far finished and can be ordered, minor improvements are still missing.

I have decided for two Capatzitive buttons which are controlled with an AT42AT1010, as a first display is a 0.96 "OLED which can be replaced by a 1.3" OLED.

I have noticed something to buildability and the components so that they can be soldered by hand.