# Building a retro gaming handheld

> Putting together a Null 2, a DIY retro handheld built around a Raspberry Pi Zero 2 W.

Author: [Luis Padron](https://thoughtsonthings.io/about/)

Canonical URL: https://thoughtsonthings.io/writing/building-a-retro-handheld/

Published: 2023-03-05

The [Null 2](https://www.null2.co.uk/) is a DIY kit for a retro gaming handheld powered by a [Raspberry Pi Zero 2 W](https://www.raspberrypi.com/products/raspberry-pi-zero-2-w/), which means most of its tools and software are open source. It runs [RetroPie](https://retropie.org.uk/), a custom OS built on Debian for running emulators, and the Pi Zero 2 W is fast enough to run up to some PlayStation 1 games. I finally got around to finishing my build.

What's in the kit:

- 1 × Null 2 PCB
- 2 × SMD buttons
- 3 × right-angled buttons
- 2 × right-angled switches
- 1 × set of rubber membranes
- 1 × TP4056 charger (the blue board)
- 1 × 3R9 SMD resistor
- 1 × 3.2″ ili9341 screen
- 1 × PAM8403 (the green board)
- 1 × PCM5102A (the headphone board) with headers
- 2 × speakers
- 4 × M3 20 mm acrylic nuts and bolts

What you add:

- 1 × Raspberry Pi Zero 2 W — nearly impossible to find at retail in 2022, I tracked stock with [rpilocator.com](https://rpilocator.com/)
- 1 × 1000 mAh 503450 LiPo battery
- 1 × set of 3 mm clear acrylic case parts
- 1 × set of 5 mm clear acrylic case parts
- 1 × micro SD card

Tools and materials you'll need: a soldering iron and station, double-sided tape, Kapton tape, 1 mm foam tape (optional), masking tape, a multimeter, flush cutters, acrylic solvent (e.g. Weld-on 4), a piece of single-core wire, and sandpaper.

## Soldering

Soldering the Raspberry Pi to the Null 2 PCB was tough since I'd had minimal exposure to it before. Definitely recommend getting a nicer soldering iron and station, and good solder.

![The bare Null 2 PCB with a Pi Zero resting on it and no other components](https://thoughtsonthings.io/_astro/pcb-bare.CjQWM8xq.jpg)
*The Null 2 PCB with the Pi Zero and no other components*

![Soldering the edge connectors of the PCB and Pi together](https://thoughtsonthings.io/_astro/soldering.DBzrfPPF.jpg)
*Soldering the PCB and Pi together*

This step was really difficult and you can see how bad most of the solder joints were. I was unable to get a connection on the ground pin, but was able to solder a wire to the test pad to resolve the issue. In the end, I reflowed most of the connections, which fixed the ground issue as well and let me remove the sketchy wire.

![The Null 2 with the screen, audio boards, and battery all soldered in place](https://thoughtsonthings.io/_astro/all-components.ByHpSn4m.jpg)
*Null 2 with all the components soldered*

The rest of the components were relatively straightforward to solder.

![Close-up of the soldered heads and components on the Null 2 PCB](https://thoughtsonthings.io/_astro/soldered-detail.DCku6ICJ.jpg)

## Building the case

The acrylic case that can be made for the kit requires a special adhesive to glue together. Of course, I spilled this glue all over my counter tops, but in the end we got it done — with quite a few glue stains.

![Acrylic case panels for the Null 2 laid out with glue stains visible](https://thoughtsonthings.io/_astro/case-glue.CgVlSZpJ.jpg)

The back panel needs to be glued to the button holders.

![The glued back panel and button holders of the acrylic case](https://thoughtsonthings.io/_astro/case-back-panel.eva0JTii.jpg)

Drying overnight.

![The assembled acrylic case halves drying overnight](https://thoughtsonthings.io/_astro/case-drying.DXr3duqk.jpg)

## Finished

![The finished Null 2 handheld in its acrylic case, front view](https://thoughtsonthings.io/_astro/finished-1.qaEn0ts3.jpg)

![The finished Null 2 handheld in its acrylic case, back view](https://thoughtsonthings.io/_astro/finished-2.DzERaNrv.jpg)

I ended up 3D printing a case in clear PETG. The acrylic is obviously clearer, but I like the toy-like design of the 3D printed one. It feels nicer in the hands and is a bit lighter and smaller.