Prep the Case

The first step is to prep the case.

Remove Back

Unscrew the four screws holding the plastic back plate and metal mid plate, and pull both out.

Remove Keyswitch Plate

Unscrew the four screws holding in the keyswitch plate and remove it.

Prep the PCB

Next you'll trim the excess NeoKey PCBs away, leaving just the 4x4 matrix needed for the 16-key pad.

Please use eye protection when cutting PCB material to avoid fragments getting in ones eyes.

Snap-apart

Use pliers to carefully snap off the top and bottom mounting strips.

Then, use your hands to carefully wiggle the extra two columns off.

Finally, remove the extra row.

Remember to save these extras somewhere safe, you can use them for another project later!

Need to create an un-even layout? Check out this guide:

Numpad 4000 Guide

Wire the NeoKey PCBs and QT Py

Follow the guide and photos below to wire up the four colums, four rows, power, ground, and NeoPixel data line.

Start by wiring the power, ground and columns. I used thin, silicone covered wire, which is nice and flexible. It is thin enough to thread through the PCB holes without first stripping the insulation, which makes it easier to "tighten" things to even lengths all at once.

After that you will cut, strip, and solder.

Thread the wires into the QT Py, then add the NeoPixel data wire and the row wires.

Solder to the PCB

Trim, strip and solder the wires on the PCB now. Then, you'll pull the wires to length on the QT Py side of things.

Board Positioning

Now you can place the QT Py toward the center of the PCB and pull the wires to even lengths with a little bit of slack.

Solder to QT Py

With the wires tightened up, you can now trim, strip, and solder them to the QT Py as shown here.

Add Switches to Plate and PCB

Click your switches into the plate and then into the PCB. Be mindful of the orientation and check that the legs line up with the sockets before pushing switches into place.

Case Assembly

To assemble the case, first drop the switch plate in and screw it in.

USB Port Extension

Use the short DIY ribbon cable and straight USB port and jack to create an easy to use connector. This fits very nicely compared to the QT Py, which will not lay flush at the port end of the case due to the keyswitch sockets.

Adhere

Use an adhesive square or double stick foam tape to adhere the bottom of the USB port extender to the metal mid-plate as shown. This will make the port stable enough for plugging and unplugging the USB cable.

Make sure not wires or ribbon cable are pinched by the plate as you close it.