This project aims to replace Gameboy original motherboard with modern replacement based on ESP32. I want to keep as much functionality of the original Gameboy as possbile, so it would look and feel just right, at least until switched on. Internally I'm using ESP32 together with PSRAM and SDCARD or SPIFFs as a storage. It should keep audio (both speaker and headphones) with volume pot. It shoud power from two AAA batteries, just as an original. It should be fully open for your modifications.
This is a work in progress and only revision A of the PCB is created so far. List of fixes and improvement is huge, and I'm planning to work on it step by step.
First version of the PCB had a long list of issues and were intended mostly to validate all the hardware working together on the test stand, rather than in enclosure. Mechanically PCB needs to be 0.8mm thin, rubber buttons are not too practical for testing and many other small things are not helping testing.
It allowed however to figure out power schematics and all the necessary GPIOs. Revision B just came from the factory, and compared to predecessor - Fix many mechanical issues - Abandoned idea of using AA batteries and switched to Li-Ion instead - Figured out power network - Few fix-ups on audio, which is still not working perfectly though (Built-in DAC is not good enough even for 8-bit concerts)
All and all, it fits perfectly Few minor glitches I'm trying to fix in the software now. Audio require more work as well.