I wanted to make cute keyboard which engage people outside DIY keyboard community. So I create butterfly shaped, colorfully blinking keyboard.
I named this keyboard "Swallowtail" from "Butterfly", "Swallowtail", and "Ageha" (means swallowtail butterfly in Japanese), because my handle name is yswallow, and a song "Swallowtail Butterfly~あいのうた~" is published in 1996 which year I was born.
In early, I planned this as 3 rows. But with sketching, I saw it like a moth. So I add a row, this keyboard has 4 rows.
In my previous design "Kidoairaku", there are 123LEDs, it have power consumption issue. It draws 3A (15W) if it is full power and becomes very hot. Can you believe existence of the keyboard which cannot connect to computer directly? So I use SK6803MINI-E instead of famous SK6812MINI-E in this design. Its power consumption is much low, and brightness is enough to use on keyboard.
And Kidoairaku series has too many LEDs, so I designed footprint for LED which use normal NPTH instead of square hole to make it easy to manufacture.
I placed all components backside to make it easy to PCBA except keyboard switches. To push the BOOT and RESET button, I made a hole. ProMicro is too long for this design. Seeed Studio XIAO enabled this design.
OrderingI ordered to Seeed Fusion by DIY XIAO Mechanical Keyboard Contest campaign. The PCBA inquiry became over $500, so I could order only PCB and separately sent XIAO RP2040 for free.
The PCB arrived after 2 weeks. The quality is OK.
MistakeI had mistaken on thumb cluster. Too narrow key-pitch and too open key-pitch.
I used one PCB for circuit, and another for bottom plate. After ordering, I found this keyboard can be thinner if I shave around XIAO's USB-C connector on bottom plate. So I shaved.
Seeed Studio XIAO has only 11GPIOs. If you have designed keyboard, you may think there can be only 30 keys in (standard) matrix. Although, this has 54 keys and LED backlighting. How did?
The answer is using improved square matrix. This keyboard uses only 8 GPIOs to scan key matrix. 1 for LED, 1 for control powering LED, and the other 1 is free. I'm planning to add piezo speaker.
To use improved square matrix easily, I choose PRK Firmware. You can use it by Drag-n-Drop firmware UF2 and put keymap.rb. To lighting up this colorfully, I implement RGB Matrix feature on PRK Firmware.
Comments