An ESP32 handheld that plays NES off a microSD card

Difficulty

Intermediate

AI-buildability

4/5

The firmware is an existing emulator that needs only pin configuration, which AI can help with, but the soldering, perfboard D-pad, power wiring and case assembly are hands-on.

Time

A weekend

Cost

$40–70

Estimates based on the original write-up. How AI-buildability is scored. Building with an AI assistant? Connect it to Afterware (free MCP server).

The brain is an ordinary ESP32 DevKit, the kind found in beginner IoT kits. Rithin K ran the Anemoia-ESP32 NES emulator on it, with Wi-Fi and Bluetooth switched off and each of the two cores given its own job: one for emulation, one for audio and buttons. The result is a pocket console that loads ROMs from a microSD card and holds about 60 frames per second.

The case is FreeCAD-designed and printed in ABS as two halves. The orange front holds the ST7789 screen and buttons, and the black back holds a 7.4V 3800mAh 2S pack, a charger/protection board, a buck converter and the speaker. The D-pad is built on small perfboard pieces, and the other buttons are standard tactile switches wired to GPIO and ground with internal pull-ups. Before the ESP32 saw any power, the buck converter was trimmed with a multimeter to exactly 5.0V.

Battery life is listed at 2 to 5 hours, with about an hour to charge. The trick worth stealing is the power-first bench test: a 2S pack and a bare ESP32 can take each other out, so bring up the buck converter alone before anything else touches it.