bgkendall / nav-switch-mount

Simple 5-way navigation switch mounting PCB for use with hand-wired keyboards

Nav. Switch Mount

This is a simple PCB for mounting through-hole 5-way navigation switches such as the ALPS SKQUCAA010. It is intended for use in keyboard projects and provides a way to both secure a nav. switch and easily wire it into a keyboard matrix.

This switch has been discontinued by ALPS, but equivalents can be obtained from Adafruit and various vendors on AliExpress¹.

This repository contains the KiCad PCB design files and Gerber format files for PCB production. Zipped Gerber packages are included in the release assets.

Additional Components Required

• 1 × ALPS SKQUCAA010 (or equivalent) navigation switch
• 5 × 1N4841 SOD-123 SMD diodes

Options

The current (v2) PCB is 22.9×13.2mm. The diodes can be mounted on either side of the PCB. Connections to the board are via wires that align with MX switch centre and alignment pins.

The first version of the PCB came in two variants:

• 1-sided — 24.3×13mm — the switch and diodes are all mounted on the top of the PCB.
• 2-sided — 22.3×12.6mm — the diodes are mounted on the opposite side of the PCB to the switch. Wire connections are via pads.

Wiring

The switch and diodes are installed as marked. Diodes may be soldered on the opposite side to the switch (positions D1—D5) or on the same side as the switch (∆1—∆5) depending on preference. The PCB is wired into the keyboard matrix via the holes on the underside. The Row hole/pad is the common pin for the switch and should be connected to a row pin on the MCU. The other holes/pads should be connected to columns, with the silkscreen near the connection point indicating the direction (see notes below). The holes are specifically designed to line-up with the centre and two alignment pins of an MX switch, allowing the wires to easily run through to the back of the keyboard’s PCB. However, the best routing will depend on the exact board being modified — in some cases it may be desirable to run the wires between the plate and PCB.

It is recommended that masking tape is used to prevent solder from building up on the upper side of the board (in a similar manner to when socketing an MCU) and the wires will need to be soldered from the bottom side (i.e., from the opposite direction from how a wire would normally be soldered).

Notes

• The markings on the silkscreen orient the diodes for Column-to-Row use. For a Row-to-Column matrix the diodes must be installed in the opposite direction.
• The arrows point in the direction that the switch is actually pushed. This means that when viewed from the bottom the left and right arrows indicate right and left movement respectively.
• The ‘•’ marking indicates the centre press action².

Mounting

M2 Hardware

These PCBs are designed to be secured using M2 hardware. Two ~2.1mm holes will need to be drilled through the keyboard’s plate (or, potentially, the keyboard’s PCB, although this would need to be planned with great care!).

The mount points are in the same position relative to the centre of the PCB for both variants.

MX Adaptor

Alternatively, these PCBs can be used in conjunction with Kevin Eckert’s Nav Switch to MX Adapter. The switch’s legs should be long enough to reach past the bottom of the adaptor and through the mounting PCB. The switch’s legs may need to be straightened for ease of soldering (be careful if doing this — the fragility of these legs was one of the main prompts to create this board!).

For keyboards with a PCB, the adaptor can only be used top-mounted diodes and the mounting board must be thinner than the usual 1.6mm to allow room for the switch legs to be soldered³. The legs will need to be trimmed back as much as possible to avoid pressing on the keyboard PCB. There is not enough room between a plate and a keyboard PCB for the adaptor and bottom-mounted diodes.

Careful consideration should be given to the order of assembly when using the adaptor.

Keycaps

Options for keycaps on navigation switches:

• Adafruit Black Rubber Joystick Nubbin Cap
• Kevin Eckert’s SA profile keycap for navigation switches is available alongside their Nav Switch to MX Adapter
• If you don’t mind partially destroying a keycap, I have an MX keycap to nav. switch adaptor — this is currently untested

Footnotes

1. If no results are shown, try refreshing the page. ↩

2. On the nav. switches I have used I have found the centre press to be both vague and twitchy and have left it unassigned on most layers. ↩

3. At the time of writing 0.8mm PCBs seem to be available for no additional charge. ↩