LED Arcade Buttons

The 30mm arcade buttons in the Adafruit shop are excellent for retrogame projects. They're also quite aesthetically pleasing. They feature a translucent body with a very slim micro switch, so it's great for internal lighting effects.

Although they do not have LEDs built in, you can actually fit NeoPixels into the body with a 3D printed diffuser.

In this tutorial you'll learn how to add NeoPixels to arcade buttons.

Prerequisite Guides

Check out the following guides below to get a better understanding of the Trinket micro-controller, NeoPixels and the NeoPixel Arduino library.

• Uber NeoPixel Guide
• Introducing Trinket

Parts, Tool & Supplies

You'll need 30mm arcade button and some NeoPixel mini's (the 8mm x 10mm cuties), an arduino micro-controller and a power source. If you don't have access to a 3D printer, you can send the files to a service or check with your local hackerspace/library.

• 30mm Arcade Button
• NeoPixel Mini PCB
• 5V Adafruit Trinket
• 3D Printer
• Filament
• Flat Pliers

3D Printed Parts

All you need is these two parts, thats it (for one arcade button, at least).

Slicer Settings

You can use the settings below as a reference. The parts are oriented in the center of the bed and ready to print "as is". They do not require any support material.

Modify Design

The parts were modeled in Autodesk 123D Design and available to modify. The file includes the original solids and sketches.

Tolerances

The cap snaps onto the connector piece and they're held together by friction. The tolerances for these parts will vary depending on your print settings, but you can download and modify the design to fit your project.

Materials

For a nice soft LED diffusion, ideally you want your diffuser printed a filament with a light colored pigment. White, natural and of course transparent filament will work best.

In my demos I used glowFill, which is glow-in-the-dark PLA/PHA filament from Colorfabb. It's kinda cool that the NeoPixel LEDs charge up the material so it glows when the lights are turned off.

Arcade Button Anatomy

The arcade button is very modular and really easy to take apart. The button consists of four pieces.

• Cap
• Diffuser
• Body
• Mini micro switch

Remove the cap

To get to the clicky center of the button, we need to remove the top cap. Look for the two openings in the side of the button. You'll see a clip on the side, near the top of the opening. Use a screwdriver or flat pliers to push the clip inward and up, so that the cap lifts up from the body.

Pull off cap

If the cap is hard to remove, try pushing in both of the clips from the side. Carefully pull the cap off the button.

Remove Stock Diffuser

The stock diffuser has a stem coming from the center. Grab it and pull it out. You can disgard this or save it for another project.

Install 3D Diffuser

Insert the 3D printed diffuser into the top cap with the cut outs lined up with the clips on the sides. Press it down, all the way into top cap. The tolerances should have a tight hold.

NeoPixel Mini PCB wiring

The NeoPixels require three wires, power, data and ground. These are indicated on the pads near on the bottom of the PCB. The arrow indicates the direction of the chain.

Wiring Multiple Pixels

You'll need to determine how many NeoPixels your project will need. NeoPixel LEDs can be chained together by soldering wires from the data in to the data out. 

The wires in between NeoPixels should have a minimum length of about 6cm - This will vary depending on the distance between the buttons in your project.

Install NeoPixels

Carefully insert the chain of NeoPixels through the opening in the side of the arcade button. This opening is just large enough for the NeoPixel mini PCB to pass through.

Thread NeoPixels

If your project uses multiple buttons, you need to pull the entire chain of NeoPixels through the body of the first arcade button.

Installed NeoPixel

Pull the first NeoPixel in the chain to the center of the body and position the wires so you have some slack to work with.

Mount to Connector

Insert the NeoPixel mini PCB into the 3D printed connector using flat pliers. The PCB fits in the center of the part and held in place with the two clips on the sides. 

Fitted NeoPixel

The NeoPixel mini PCB is fitted into the 3D printed part.

Install Connector

Insert the connector into the diffuser cap with the wires lined up with the cut outs. Press the two pieces together to snap them shut.

Installed NeoPixel Diffuser

The bottom of the 3D printed connector has space for wires to pass through.

Install Cap to Body

Insert the assembled diffuser cap into the body of the arcade button with the clips lined up with the openings on the side.

NeoPixel Wire Check

Ensure the clips from the cap are in place and free to press. There should be enough clearance for the wires to be strain-free.

Light em' Up!

The NeoPixel works with most arduino micro-controllers. In this example it's wired to the 5V, GND and D0 pins on the 5V Trinket. You can use the strandtest demo sketch included with the NeoPixel Arduino library for a sweet rainbow animation and chasing pattern.