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Protozoa P.02 Build Guide

Welcome to the P.02 Build Guide.


This guide will show you have to assemble your PCB.

The P.02 uses the Discipline open-source PCB designed by coseyfannitutti from

A majority of the through Hole PCB build guide is pulled directly from build guide and for the most part it's the same. However, we have made a few small changes to the PCB to make it unique to Protozoa.


A note on quality:

All units have been inspected for external damage or defects. Units may have some scratches or anodising marks on the inside of the unit, this is unfortunately unavoidable because of the design. P.01 units may have some small dents or scratches to the screw holes on the BASE units, because of the way they were hung for anodising. This was unfortunately also unavoidable for this revision. P.01 units also have a slight colour difference on TOP and BASE pieces, because they were made in different batches. Since the design is seamless and cannot be seen from outside, this was deemed acceptable. If you have any problems with your unit, please do contact us as soon as possible and we will do whatever we can to help.


Warning: Soldering can cause harm to yourself and others. Please review this Safety Guide before beginning. You're soldering at your own risk.


Let's get started.


Here are the things you'll need to assemble your PCB: 

Recommended Items:


Included Components:

Please double check your components and quantities before beginning assembly. If you find that you are missing something please fill out our Component Request Form and we'll ship your missing components asap.

  • Atmega32A (1)
  • 40-pin IC socket (1)
  • USB Type-C port (1)
  • 6mm pushbutton (2)
  • 3mm Red LED (1)
  • 3mm White LED (1) Optional
  • 500mA resettable fuse 5.1mm (1)
  • 16mhz crystal (1)
  • 6 pin header (1)
  • 22pF capacitor (2)
  • 0.1uF capacitor (2)
  • Zener diode 3.6V (2) Do not mix up with 1N4148 diodes
  • 1.5K resistor (2)
  • 5.1K resistor (2)
  • 75R resistor (2)
  • 10k resistor (1)
  • 22k resistor (1) Optional
  • 4.7uF capacitor (1)
  • 1N4148 diode (~90) There will be extras

 Mysterium PCB Componets




Step 1: Install 1N4148 Diodes

This part has a specific orientation! – The black bar on diode will point upward and line up with the square pad.

Bend legs straight down as close to diode as possible and insert. Solder and clip the legs. D71 marked “ISO” near left shift switch position only needed for ISO layout.





Step 2: Install (2) 3.6V Zener Diodes

This part has a specific orientation! – The black bar on diode will point upward and line up with the square pad.

These two diodes will be separated from your other diodes. They are NOT interchangeable. Use same method for soldering.





Step 3: Install Resistors

  • 1.5K resistor (2)
  • 5.1K resistor (2)
  • 10k resistor (1) if using Red LED or 22k resistor (1) if using white LED
  • 75R resistor (2)

If using the white LED make sure to use the 22k resistor instead of the 10k resistor. Reason being, the white LED is very bright when used with the 10k resistor.

These resistors do not have a specific orientation. Insert based on labeled resistor value and solder using the same method you used in steps 1 and 2.





Step 4: Install USB-C Port

Warning: This is the most challenging part of the build. Take your time and remember it's always easier to add more solder than to take it away.

Insert and flip board over. Solder only one of the large bottom legs. Heat up soldered pad and press down to ensure the port is flush before soldering the other three legs.

For the small pins you are going to use a different technique than the rest of the components. The technique is called "Drag soldering". Here's a video of how it's done.

Using your flux pen, apply flux across the pins and pads for USB-C port. Apply a very small amount of solder to the first pin and drag your iron across the pins. Repeat until all holes are filled.





Step 5: Install (2) Push Buttons 

These buttons do not have a specific orientation. Insert buttons into the appropriate holes. Turn the board over and solder one leg for each switch. Then reheat the solder joint while pushing on the button to make sure it's flush and aligned. Solder remaining legs.





Step 6: Install (1) 6-pin Header

The longer side of header is the top side. Insert the shorter side of the header into the PCB and solder only one pin. Then reheat the pin and press down from the top to align flush with the PCB before soldering the rest of the pins. Heat will transfer from the bottom of the pin to where you are pushing down. Use rag or glove to protect your hand from the heat.





Step 7: Install 500mA Fuse

This part does not have a specific orientation. Insert the fuse into the PCB, turn over and solder both pins. Flip the PCB back over and fold the fuse over to the left as pictured. 





Step 8: Install LED

This part has a specific orientation! The short leg and flat side of the LED lines up with the square pad. If you soldered in the 10k resistor in step 3 use the Red LED if you soldered in the 22k resistor use the White LED.





Step 9: Install 7uF Capacitor

This part has a specific orientation! The longer leg goes to the square pad and the white mark on the capacitor will be pointing upward.





Step 10: Install 16mhz Crystal

This part has no specific orientation. Insert the crystal into the PCB, flip over and solder only one pin. Hold down the crystal and reheat the soldered joint to align the part. Solder the other pin.





Step 11: Install (2) 22pF Capacitors

This part has no specific orientation. These capacitors are the smaller blue capacitors with straight legs.





Step 12: Install (2) 0.1uF Capacitors

This part has no specific orientation. These capacitors are the larger blue capacitors with winged/wider legs.





Step 13: Install 40-pin IC Socket and Atmega32A

Do not insert the Atmega32a microcontroller into the 40-pin socket before soldering the socket into the PCB.

Take note of the notches marked on the PCB, socket and microcontroller. It's important that they all align for proper orientation.

Solder two opposite corners of the IC socket. Reheat the soldered pins and press down on each to ensure socket is flush with PCB. Then solder the rest of the pins. Insert the microcontroller into the socket, with the notch on the left side. You may have to gently bend the pins slightly inward for proper alignment with the socket.





Step 14: Test the PCB

Plug your finished PCB into your computer. Open up VIA or similar key tester and test your keys by shorting the switch pads with tweezers. Here's a video of how to do it.


Step 15: Install Stabilizers

This case and PCB is compatible with both clip-in and screw-in style PCB-mount stabilizers. Install stabilizers into the PCB.


Step 16: Install Optional PCB Foam

With your stabilizers installed, lay included PCB foam on top of the PCB and align it accordingly. Then place the included switch plate on top of the PCB foam. If you are not using the included foam, skip this step.


Step 17: Install Switches

Install all switches into the plate making sure to align all switch pins with the correct holes in the PCB. Also, be sure to fully seat your switches in the plate. You'll hear an audible click when your switch is fully seated.

Solder all switches into place. At this point you should retest your PCB.


Step 18: Install Case Feet

Place your assembled Plate and PCB to the side and grab the P.02 case. Flip the case over to find two horizontal channels machined into the surface. These channels are for the included silicone feet. Pull back a small amount of the adhesive backing and align the foot to the end of the channel. Pull of the rest of the adhesive backing and align the other side of the foot to the other end of the channel. Press down the foot on the ends and slowly work your way towards the middle.


Step 19: Unscrew Case Bottom

Locate the screws on the bottom of the case and unscrew them to separate the case bottom from the top. Set case bottom aside.


Step 20: Install Acrylic Window

With the case top upside down so that you have a view of the inside of the case, lay the window in to the forehead. There is a specific orientation to the window. The rounded corners face the back side of the board (the usb port side). There is protective film on both sides of the window. Remove the film on the side facing the top of the case before slotting it in. Slot the window in one side at a time leaving a slight bow in the middle. Once the window is slotted in remove the film on the other side. Try not to touch the inside of the window, leaving fingerprints or dust. The window is a bit oversized by design so that it will not rattle once the wedge is in place. Once the case is screwed together the window will sit flush. 



Step 21: Install Wedge

Place the wedge on top of the window. Due to the slight bow in the acrylic window, the wedge will not sit all the way down in the slot. Do not try to push the wedge down to flatten the acrylic window. Once the case is screwed together the base will push up on the wedge fully seating it into the slot and applying even force on the acrylic window to flatten it. It's important that the wedge is not leaning at an angle towards the front of the case (pictured above). Otherwise, it will prevent the assembled plate/pcb from fully seating in the case.


Step 22: Install Assembled Plate & PCB into Case

Place your fully assembled plate and PCB into the top of the case making sure to align all mounting points on the plate to the appropriate mounting points on the case top. Use the included M3 screws to attached the assembled plate and PCB to the case top.


Step 23: Install Optional Case Foam

With the plate and PCB mounted in the case, place the included case foam on top of the PCB. If you're not using the case foam skip this step.


Step 24: Install Bottom of Case

With the case top still face down, gently lay the case bottom on top making sure to align everything appropriately. Once the bottom is fully seated, install the included M3 screws in a cross pattern to seal the case. Do not over-tighten, once you feel resistance you can stop. 


Step 25: Install Keycaps

Pick your keycaps, Install and enjoy!