Plan C: Raspberry Pi CM4
Move to a Linux application processor with the largest software ecosystem: a Raspberry Pi Compute Module 4 (4 × Cortex-A72 at 1.5 GHz, VideoCore VI GPU, Wi-Fi and Bluetooth on the module) on a carrier board of our own design. Raspberry Pi states CM4 production until at least 2034.
All costs and durations on this page are estimates for one developer working with Claude, to be refined after the study phase.
Requirements
| Requirement | Result | Notes |
|---|---|---|
| MAME | 🟢 | MAME 2003-Plus / FinalBurn Neo, through CPS2 and Neo Geo |
| 16-bit | 🟢 | all, full speed |
| 32-bit | 🟢 | GBA, 32X, Sega CD, Saturn partly |
| PlayStation | 🟢 | full speed |
| Nintendo 64 | 🟡 | much of the library playable, a bit ahead of the RK3566; the CM5 would be the upgrade for the heaviest games |
| HDMI | 🟢 | two HDMI ports on the module |
| Wireless controllers | 🟢 | Wi-Fi 5 + Bluetooth 5.0 (Classic and BLE) on the module |
Six of six requirements, N64 partly.
What changes
| Area | Change |
|---|---|
| Processor | ESP32-S3 → CM4 (wireless variant) on a carrier board, two high-density board-to-board connectors |
| Display | changes: MIPI-DSI or DPI (RGB) panel; the Pi supports both through standard overlays |
| HDMI | connector routed from the module. The built-in DSI screen stays the default; Linux (DRM/KMS) sees the cable plug and unplug, and the frontend moves the picture to the TV and back, as existing handheld distributions already do |
| Audio | needs the I2S amplifier: the CM4 has no analog audio output |
| Power | changes: 5 V at up to ~3 A under load, so a larger charger / boost than the IP5306; heatsink or thermal pad |
| Software | changes completely: Raspberry Pi OS based distribution (RetroPie, Batocera or Lakka) with RetroArch + EmulationStation; carrier support is mostly device-tree overlays, the best-documented path of the three |
| Enclosure | redesign: new display, thicker and with a thermal path |
| Boot | 10–20 s instead of instant-on |
Time
| Phase | Estimate |
|---|---|
| Study on a CM4 + IO board: N64 / PS1 measured, controllers, power draw | 2–3 weeks |
| Linux integration: display overlay, buttons, I2S audio, power | 4–6 weeks |
| Carrier board schematic + PCB | 6–8 weeks |
| Fabrication and first-article bring-up | 3–4 weeks |
| New enclosure | 3–4 weeks (in parallel) |
| Total | ~5–7 months |
Cost
| Item | Estimate |
|---|---|
| Development kit (CM4 + IO board) | ~$80–120 |
| BOM per console | ~$80–110 (CM4 with wireless ~$45–65 by RAM / eMMC, DSI panel, power stage, carrier PCBA) |
| Battery life | ~4–5 h on a 5000 mAh cell, ~2.5–3 h on the v1's 3000 mAh 103665 (higher draw than the RK3566) |
Risks
- Higher power and heat than the RK3566: shorter battery life, a thermal path in the enclosure.
- CM4 prices and stock have swung in the past.
- Same PCB step-up as Plan B (dense connectors, DSI / HDMI pairs).
When it makes sense: the fastest route to a working Linux handheld, with the most documentation, and a pin-compatible path to a faster module later.