One of the advantages of the TRRS Trinkey is that no soldering is required to connect the device to the display or to the AT Switches. Everything simply plugs together. We have included STL files for a 3D-printed case for the Keyboard and Mouse Emulator.

If you are only using the device for switch control, you do not need the display. You will want to add this case for the board.

To secure the display board in the enclosure, you can fasten it with M2.5 plastic screws or snap it onto some alignment pins and secure it with a drop of glue. Adafruit sells a nice little box such screws which are handy for this and many other projects.

Most Trinkey boards sold by Adafruit are intended to be plugged directly into a PC, laptop, or USB hub. If you're using this device for switch control, you will have no problem plugging directly into such receptacles. However, it is unlikely you could see the display board from that location. So if you're using a Keyboard and Mouse Emulator with a display, you will need a USB extender cable similar to this one from Amazon which has a USB A female connector on one end and a USB A male connector on the other end.

AT Switches

Assistive Technology Switches have a 3.5 mm Mono plug on them. They can be obtained from a variety of sources. If you aren't sure what kind of switch works for your disability, we recommend the "Adaptive Gaming Kit" from Logitech. It contains an assortment of switches of various kinds that you can try out.

The TRRS system is traditionally used for stereo headphones plus a microphone channel. If you are using more than one switch you will need some sort of splitter to separate the three channels.

If you only use one switch, it can be plugged directly into the TRRS Trinkey jack. Note that the keyboard & mouse emulator requires at least 2 switches however Switch Control can be used single switch.

If you are using 2 switches you will need a splitter that brings out the left and right headphone channels.

If you require all 3 switches (which is ideal) you will need one adapter that splits out the microphone channel from the headphone channel and then another adapter that splits the headphones into the left and right channels. Unfortunately, we have not found a commercially made adapter that splits out all three channels. We have built custom adapters that do so but that requires soldering skills.

Here are 2 commercially available splitters that separate the microphone channel from the headphones.

2 Pack Dual 3.5mm Jack Splitter, Headphone and Mic, TRRS 4 Pins from Amazon

The black one on the left splits the headphones from the microphone. The right one on the right does not do anything useful for us. It simply duplicates the headphone jacks but does not split out the left from the right channel.

Here is a similar device.

MillSO Headphone Mic Splitter from Amazon

The green jack is the headphone jack which will have to be split and a pink one is the microphone jack that can be used directly.

Here is an example of a splitter that converts stereo headphone channels into individual left and right channels. It can be used for a 2-switch application or in conjunction with the previous devices for a 3-switch application.

3.5mm Stereo to Dual Mono Cable from Amazon

Here are photos of how to use these devices in combination to break out 3 Mono switches from a TRRS jack.

Here is a 2 switch application

If you want to mount the case for the Keyboard and Mouse Emulator you will need a 1/4"-20 hex nut available from any hardware store or this one from Fastenal.