Pizza Pad PCB - Solder Guide

✨ PRETTY PAD - BUY NOW ✨

This kit is a great introduction to soldering because it's relatively straight-forward and simple to assemble while also having a range of different PCB pads to practice soldering onto. There aren't too many parts to overwhelm you but there is still enough work required to give you good exposure to soldering so you can learn from the experience.

To keep things beginner friendly, the PCB has labels to show where everything needs to go and outline the correct orientations. This side of the PCB will be referred to as the "Bottom" while the opposite side will be called the "Top". 

TLDR: Solder Sockets > Diodes > Micro-controller

Components:

  • Pizza PCB
  • 2x Header Pins
  • 1x Seeed Xiao
  • 9x Hotswap Sockets
  • 9x 1n4148 Signal Diodes

Required Tools:

  • Solder and a Soldering Iron
  • Flush Cutters
  • Tape (Optional)
  • USB Type C Cable

Step 0 - Flashing the Seeed Xiao 

Have a computer and a connected USB Type-C cable ready. To make the microcontroller work as a keyboard, we will need to change the Seeed Xiao firmware to our custom .UF2 file

  1. Open and remove the Xiao from the plastic packaging.
  2. Press and hold the Boot Button (labelled B) while connecting the USB C cable. This is how we enter Bootloader mode and the Microcontroller will now show up in your computer’s device list (similar to a USB Stick).

  3. Drag and drop the .UF2 bootloader file to this new Seeed Microcontroller device.
    If everything was done correctly, the Microcontroller will disappear from the device menu and your computer will show a notification confirming “PizzaPad” has been connected successfully.

    Download Bootloader File - idyllic_pizzapad_via.uf2
    https://cdn.shopify.com/s/files/1/0599/5914/8737/files/idyllic_pizzapad_via.uf2

  4. Open VIA - https://usevia.app/ and click "Authorise Device +". 
    Connect the PizzaPad and then navigate to the settings tab and enable "Show Design Tab".
    In the "Design" tab, load the JSON file and you will now be able to program the buttons. 

    Download JSON File - pizzapad_v3.json
    https://cdn.shopify.com/s/files/1/0599/5914/8737/files/pizzapad_v3.json
    (Depending on your browser you may need to "Right Click + Save As")

Step 1 - Installing the Sockets


Place the Hotswap sockets onto the PCB in the correct orientation. You can tell a socket is installed incorrectly if it is blocking the switch hole. 

 

In the example above, you can see I've installed 1x socket incorrectly. Please check for mistakes BEFORE you solder to avoid the extra hassle later.

Use tape to secure the sockets into place while you solder

Alternatively, install some switches for extra support 

Remember to heat the PCB pad and the socket with the soldering iron when adding solder. Heat areas A and B while making sure there is enough solder at point C to provide a stable connection. Do not heat the pad for longer than 5 seconds at a time. 
 
Solder only one side of a socket and do not immediately solder the other side, just yet, because we need to make sure it is flush with the PCB. 

Heat your newly soldered pad again while pushing down on the plastic part of the socket with your other hand to confirm it is aligned correctly. When you are certain the socket is flat, let the solder cool and move onto the remaining pad on the other side. 

This is a correct socket.

This is an incorrect socket. 

Step 2 - Installing the Diodes


These through-hole signal diodes are what stop keys from "ghosting" and allow you to actuate multiple keys at once. They have long legs that will need to be trimmed. If you do not have flush cutters, as a last resort, nail clippers can be used. 


Install the diodes in the correct orientation. The black line on the diode will need to match the black line on the PCB. 

Similarly to the sockets, use tape to hold the diodes in place so they do not move around during soldering. Alternatively, on the other side of the PCB, you can also bend the wires to prevent them from falling through.



We will be soldering the pads at the Top of the PCB. Alternate between heating Point A and B, before finally leaving the soldering iron tip on Point A, while feeding solder to the pad. Do not heat the pad for longer than 5 seconds at a time. 

Once you are happy with the solder joints, trim off the excess diode legs. 

Step 3 - Installing the Seeed Xiao Controller

Install the header pins while making sure the "black plastic" is on the Bottom side of the PCB. You can push this against a flat surface to make sure the pins are as flush as possible with the PCB. 

The Header Pins are purposely in a "zig-zag" pattern to keep everything in place via friction. 

Install the Header Pins with the short side facing up if you want to trim the legs after soldering. 

Install the Header Pins with the long side facing up if you want to leave the pins and do not want the extra step. 

Position the Micro-controller with the USB Port facing downwards. This is important because we want easy access to the reset button. 

Solder all the Header Pin pads on both sides of the PCB. Heat the pads and add solder; at this point you should be an expert!

We can now move onto assembling the case and finish building the Pretty Pad.
Build Guide: