The miniGB that's the talk of the town

It seems that something called miniGB available on Aliexpress is becoming a topic of discussion in the streets. You can check what it is in the following video.

I don't want to play with it as an emulator, but I'm interested in programming it because it looks interesting. Looking at the disassembly in the video above, it seems to be a custom-made board using Raspberry Pi pico as a chip. So, I thought it could probably be programmed and placed an order. It costs about 9,000 yen each, so it's not cheap, but it feels pretty good to have since it seems handmade. (I actually got a good impression because it has a handmade feel).

I tried disassembling it right away.

I was wondering how to get into BOOTSEL mode, but there was a small hole for the BOOTSEL button on the bottom right on the back, and I was able to get into BOOTSEL mode by pressing it while turning on the power.

I tried extracting uf2 with picotool to see if I could get any information.

$ ./picotool.exe save microgb.uf2
Saving file: [==============================]  100%
Wrote 1087488 bytes to microgb.uf2

$ ./picotool info -a microgb.uf2
File microgb.uf2:

Program Information
 features:      USB stdin / stdout
 binary start:  0x10000000
 binary end:    0x10084b64

Fixed Pin Information
 none

Build Information
 sdk version:       1.5.1
 pico_board:        pico
 boot2_name:        boot2_w25q080
 build date:        Mar  5 2024
 build attributes:  Release

Unfortunately, it contains no pin information. Button numbers could probably be analyzed by tracing the lines on the board, but the issue would likely be with the LCD.

From this information, I don't know how to find out which LCD it uses, so if anyone knows, please let me know The LCD itself seems to use a higher resolution than the original GB, and it seems that part of it is hidden by the front panel to match the number of pixels. The rest of the extra parts seem to be hidden by covering them with black tape. In principle, it might be possible to make a larger GB-like device, probably even outputting about 16-bit color.

It seems to be connected via SPI, so I would like to try to find out the model number of the LCD. ST7789(V)/ST7735S type drivers are commonly used with rp2040, so I guess I'll start fumbling with that... The diagonal of the LCD is about 3.6 cm, so it's about 1.3~1.4 inches. (I need to remove the tape to know the exact size) I would like to see if anyone else is analyzing this.

---

There are projects to emulate Gameboy with rp2040 below, so I imagine the software is used while creating our own boards, LCDs, and buttons.
Pico-GB
RP2040-GB

---

P.S. It seems that there are also some made with ESP32. This one appears to have a higher degree of completion, but it might be a bit larger in size

---