After failing my first attempt, everything works perfectly now.

Specifications:
- 3.5 inch TFT display
- Raspberry pi zero W
- (2x) 4800 mah battery (4/5 Hour playing time)
- battery status led's
- L & R shoulder bottons
- Y & X buttons
- shift button for additional key functions
- WIFI and bluetooth build in
- USB port on the side
- Buttons for screen resolution and contrast in battery compartment
- safe shutdown build in
- HDMI port
- mirco sd cartridge
the case:
Cleaning the case:
I bought a lot of old gameboy shells. Most of them are yellowed.
I used "Oxycream", this is a hydrogen peroxide based shampoo used by hairdressers:
http://www.hairmix.nl/product/oxycreme- ... l-1000-ml/
















I bought a second battery so I can change batterys when one is empty.
To charge both batteries, I have made an external battery charger.
I modified an original Samsung i9100 charger: https://nl.aliexpress.com/item/i9100-Ba ... 97128adebf.
To make the battery fit imoved the pogo pins to the other side of the charger.
Now I can charge both batteries, one in the external charger and the other in the gameboyzero through the usb port of the charger.









Thanks to all the forum users!