Build a Portable Raspberry Pi RetroPie Handheld – Part 1

This guide walks you through creating a portable RetroPie handheld powered by a Raspberry Pi. It focuses on the electronics and testing phase, assuming you already have a basic understanding of SD‑card imaging and GPIO wiring.

We’ll keep the Pi itself unmodified and rely on external wiring, a custom controller, and a simple case. The result is a lightweight, battery‑powered retro gaming system.

Estimated cost: $100 + (actual price may vary depending on parts chosen).

Key components you’ll need:

• Raspberry Pi Model B (or newer)
• 8–16 GB micro‑SD card (minimum 8 GB for the 3.4 GB RetroPie image + games)
• Car backup monitor (or similar 5 V LCD) – many work out of the box
• Power bank or Li‑Po battery pack (higher mAh for longer playtime)
• Controller: custom‑built or repurposed console controller
• Plastic or acrylic sheets for the case
• USB A & micro‑USB cables, flat ribbon cable (e.g., 2×13 IDC)
• Speaker, small amplifier circuit (LM386), and optional headphone jack
• Miscellaneous: screws, epoxy, superglue, wire strippers, soldering iron, rotary tool, sandpaper, spray paint, bondo

Tools you’ll need: soldering iron, wire strippers, rotary tool, superglue, hot glue, epoxy, and a computer with a mouse/keyboard for the Pi. You’ll also need a secondary PC or an SD‑card reader to transfer the RetroPie image.

Part 1 focuses on getting the electronics ready and performing iterative tests.

1. Prepare the Pi: Flash the RetroPie image onto your micro‑SD card. Instructions are available at Retropie blog, which also covers controller mapping.

2. Initial testing: Boot the Pi with a basic OS or directly with RetroPie to confirm the hardware works. Test the display and power supply before proceeding.

3. Transfer games (optional at this stage): Use WinSCP or a similar tool to copy ROMs to the Pi’s storage.

4. Planning: Sketch a rough layout of how the Pi, screen, battery, and controller will fit. Helpful references include Ben Heck’s YouTube series on portable Pi builds: Video 1, Video 2, Video 3.

5. Wire management: Trim cables to a practical length. Remove excess plastic from connectors (e.g., RCA, headphone jack, USB) to save space.

6. Connector strategy: We use breakout connectors rather than desoldering the Pi’s pins, keeping the board unmodified for future use.

7. Audio: Build a minimal LM386 amp (no gain) – schematic here. A small speaker (even a birthday‑card speaker) fits nicely.

8. Display considerations: Many backup monitors require 12 V, but the model I purchased (eBay #161044070171) runs flawlessly at 5 V without alteration.

9. Controller assembly (if custom): Use rubber tactile switches (e.g., eBay #170659489028) to emulate membrane buttons. Wire them to a 2×13 ribbon cable.

10. GPIO remapping: Follow Phill Burgess’s tutorial on Adafruit’s site (Retro‑Gaming with Raspberry Pi). Replace the sample C code with the actual keycodes you mapped in RetroPie. Document your pin assignments in a simple diagram.

11. Functional test: Flick a mapped switch (e.g., left arrow) against a ground pin. If the RetroPie menu responds, the wiring is correct. Proceed to solder the remaining switches.

12. Power management: Add a power switch that controls the Pi, screen, and amplifier from the battery pack. A small ground‑plane board can help keep connections tidy.

13. Prototyping: Use a small amount of superglue to hold components in place while you finalize the case design. Double‑stick foam works well for securing the speaker.

Part 1 concludes here. Part 2 will cover case construction and final assembly. For visual reference, check out my build videos (links omitted for brevity).