Start by placing the header pins in to the pin holes designed for the Pi Zero:
And mount the Pi Zero this way:
It’s recommended to put a kapton tape or anything in between the adapter and pi zero to avoid shorts before soldering the header pins to the Pi.
The next step is to cut the pins and plastic below the header pins and solder them to the DPI Adapter.
The final step is to solder the Pi Zero’s USB data pins (D+ and D-) to the 2 holes on the DPI Adapter. These holes will connect the Pi Zero’s data pins to the D+ and D- pads on the adapter for connecting any USB device. (Note: The D+ and D- pads on the DPI board are mislabeled. The upper pad should be D- and the lower pad should be D+. Thanks to Paul for reporting.)
The 5VIN and GND pin holes below the tinkerBOY DPI Adapter are your 5v and GND inputs.
Most of these 3.5″ screens are intended for 12v power supply. The 12V input goes to a chip called XL1509 and converts that to 5V. Like any DC to DC converter there’s always going to be wasted power as a result of the conversion. This is the reason why I highly recommend that you do the 5v mod eventhough the screen works if you feed it with 5v without the need for any modification.
To make the connections more reliable let’s remove the Female JST connector..
..just be careful not to lift the contact pads which I’ve mistakenly done here. Luckily the board has two video connections which are AV1 and AV2. I will be using the AV1.
Cut the cable that came with it and solder the wires directly to the board. In order to do the 5V mod, you just solder the RED wire directly to the XL1509’s Pin 2 or to the SS24’s cathode pin which is easier to solder to. The other end of the RED wire goes to your 5v power supply of course (PowerBoost 5v output). Since the Raspberry Pi only requires just one video connection, solder the YELLOW wire to the Pi’s TV connection. Join the WHITE and BLACK wire and solder them directly to the GND pad on the screen board. The WHITE(GNDTV) wire goes to the GND beside the TV pin on the Pi while the BLACK wire goes to your normal powerboost’s GND output.
I finally had time to populate and test my DPI adapter prototype which will be included as part of my all-in-one board for Game Boy Zero / 3. So far it’s working fine. The DPI screen looks way better than composite.
I actually built a Game Boy 3 using just a simple FPC breakout board for doing the DPI connections but it was very difficult to make it work. Obviously because of all the wires I soldered to the Pi which are prone to interference. But I managed to make it work anyway. So I made a prototype to make it easier to use a DPI screen.
The AIO board will be compatible with Raspberry Pi Zero and Pi 3. Both will have sdcard access from the “CONTRAST” area of the Game Boy case.