FearThree-Macropad

A simple and open source 3 key hand-wired macro pad with QMK and VIA Support. Made from modifiying the case files generated with the swillkb plate and case builder, as well as some help from this awesome handwired keyboard guide written by Ben Chapman:

A FearThree Built with L+F Gateron Yellows, PLA case, and GMK Dogethink v2 Artisans

Parts & Software Required

• Pro Micro / Elite-C (note: elite-c is untested as I did not have an extra one on hand)
• Micro USB / USB-C Cable
• 3 MX Switches
• 3 MX Keycaps
• Access to a 3d Printer & slicing software
• The 3d Printed Case
• 4 M2x16mm Screws
• Small Hookup Wire
• Solder & Solder Iron
• Some electrical Tape
• QMK Toolbox
• Optional but recommended: VIA

Build Guide

Step 1: Printing the parts

First you are going to need to print the parts of the case out. I used PLA on my Prusa mini with the following settings:

0.15mm QUALITY Preset in PrusaSlicer With the following Modifications:
* 10% infill
* Gyroid infill pattern

The parts are quite small, so you should be able to print all of the parts in one go.

The stls are located in the repo HERE and the Fusion 360 files are located HERE if you would like to modify the case. psst: you can get a fusion360 license for free with a student email!

Once the parts are printed out, I recommend doing a quick test fit for the parts as shown below, the pro micro should loosly fit in its corrosponding hole and not be too hard to remove and the mx switches should click into the switchplate.

Step 2: Flashing The Pro Micro

Download QMK toolbox and the corresponding firmware file you would like to use.

I highly suggest you use the VIA version, FearThree_default_via.hex, for easy key remapping without having to re-compile the firmware.

If you would like to create a keymap in QMK The Keyboard Folder is located in the repo HERE

Once you have chosen your firmware, open QMK toolbox and plug the pro micro into your computer.

Select your firmware file and select atmega32u4 for your MCU aswell as check the Auto-Flash Checkbox:

Then using a paperclip or some tweasers, quicky short the RST and GND pins on the pro micro twice while it is plugged into your computer. This should allow QMK toolbox to flash the firmware. It may not work and qmk toolbox may show Access Denied. If this happenes, just keep shorting those pins, retrying the process until it works.

Once the firmware is flashed you should get a message that looks like the following:

Step 3: Wiring The Switches

Now that our pro micro is ready we can begin to wire up our switches.

Wiring Diagram:

Luckily since we only need to wire up three switches, there is no need for any diodes as the pro micro has plenty of pins for us to use.

Wiring Step 1:

First, install your desired switches into the switchplate and prepare a piece of hookup wire, if you have multiple colors to use it definitely aids in not mixing wires up.

This first piece of wire will be the black on in the diagram, our ground. This wire will connect to a pin on all 3 switches and connnect to the ground pin on our pro micro.

Using a wire stripper, remove the shielding of the wire where it needs to connect to the switches and solder it, as seen below:

Wiring Step 2:

Once the ground wire is done, cut 3 more pieces of wire and solder them to each switch, cable management can be improved by making the red wire shorter than the green wire and the green wire shorter than the yellow one:

Wiring Step 3:

Next we can strip the end of each wire and solder it to its corresponding pin on the pro micro:

Nice! Now all of the soldering is done.

Step 4: Final Assembly & Testing

Its now time to put everything all together! Start by using 2 small pieces of electrical tape on the back and front side of the pro micro, this will allow it to friction fit into its part of the case by giving the back part a little bit more thickness. Use another piece of electical tape to cover the back switches, to prevent any possible shorting to the pro micro:

NOTE You want the USB port to be on the right side, and the switches to be south facing, when aligning the plate to the case.
See this photo for reference: Note the direction of the Gateron branding.

Then assemble the case in the following order top to bottom and insert the screws. The holes are just the right size to allow the screws to screw in without having to use any nuts:

Step 5: Final Step: Testing & VIA

Now its time to setup VIA so we can reprogram our keys.

First download via from HERE if you have not already, as well as the VIA json file from the repo HERE

This json file is needed so VIA can know how our macropad is wired. Once VIA is opened, click the settings tab and make sure Show Design tab is checked:

Then click the design tab and click load, selecting the downloaded json file, your VIA should look like this once the json is loaded:

Now plug in your FearThree and navigate to the configure tab, it should now show up and be programmable! More info on how to use VIA is available in an awesome video made by Austin V HERE

You can also double check your wiring by navigating to the Key Tester tab and checking the test matrix box. Each time you press a key it should glow up pink on VIA:

Done!

I hope you enjoy your new 3 key macropad! If you have any questions feel free to send me a message on reddit: /u/fearherbs