Seeed XIAO RP2040 Keyboard

I have a non-IT job. But I do type a lot of letters every day. I am not a typist. So when I found out that I could make a keyboard that worked for me, I was very happy. Borrowing the wisdom of my predecessors, I made a keyboard for myself. At first, I made a keyboard using pro micro. Eventually, I learned that the raspberry pi pico could also be used to create a keyboard, and I knew that the RP2040 had great potential. I made a keyboard using RP2040. This time, I received the Seeed XIAORP2040 from Seeed, and decided to make my own keyboard to match it. One of them is this cool753xiao.

Step one GPIO Pin

The XIAO RP2040 has 11 freely usable GPIO Pins, which is less than the pro micro I've used so far, so I needed some ingenuity.

Of the 11 wires, one was for the LED, two were for the rotary encoder, and the rest were eight. If you do 8 in a normal matrix, it will be a keyboard with a maximum of 16 keys. 16 keys are enough for a macro pad. However, the keyboard I was thinking of making is a 53-key keyboard with arrow keys and number keys added to the 30% keyboard. Therefore, we made it possible to use up to 56 keys by using a round-robin matrix for 8 pins.

Step two PCB

I generate my own keyboard layouts at the Keyboard Layout editor site. It is a very convenient site. Based on this data, design with kicad. But that's it. Wiring is just like solving a puzzle. Maybe I'm lucky that I'm not an expert. I don't have enough knowledge to worry about it.

Step three build

Thanks to Seeed Fusion's generous promotion, I was able to get 5 PCBs for free. All that is left is to assemble it. Speaking of ingenuity, the Seeed XIAO has parts soldered on one side, so you can make it thinner by hollowing out a part of the PCB.

In addition, I used elecrow's acrylic laser cutting service to prepare the acrylic that covers the sides of the keyboard.

Step four Complete

I soldered the diode and the switch socket on the back side of the PCB in that order. Next, I soldered XIAO RP2040 on the surface. Finally, I soldered the rotary encoder. I plugged the switch into the switch plate and mated it with his PCB. After that, the acrylic side parts were attached and the bottom plate was screwed to complete.

Step five Firmware

It is my own impression, but PRK_Firmware is used more than KMK_Firmwa in self-made keyboards in Japan. Both are excellent firmware. I made a keyboard cool836pico with KMK_firmware and a keyboard cool836rp with PRK_Frimware. Considering the hassle of switching from QMK_Firmware, which I think is often used in self-made keyboards, I thought PRK_Firmware was good and adopted it for this keyboard. Considering the future, it is a big reason that the keymap editing tool remap can also be used with PRK_Firmware.

Keyboard impression

After designing, building and using it, cool753xiao is cool and easy to use. However, this is due to my lack of knowledge, so I'm responsible, but I'm worried about the behavior of the layer key. If this point is not improved, it will be my personal hobby keyboard. With this failure, I am trying to make another keyboard using the Seeed XIAO RP2040. In that sense, I think that the keyboard using XIAO RP2040 can be used sufficiently.