I needed a mute button. One key that would instantly silence my mic during calls. Sounds simple, but every solution felt wrong. Fumbling through menu bars. Memorizing obscure system shortcuts. Installing yet another utility app.
Then I went down a rabbit hole that ended with me soldering 120 diodes at 2 AM.
This is the story of building my first split mechanical keyboard: the Sofle Pico.
Why a Split Keyboard?
The ergonomic pitch is real. Your shoulders shouldn't hunch inward eight hours a day. A split keyboard lets you position each half at whatever angle feels natural. But honestly? That wasn't what sold me.
What sold me was the idea of a keyboard that adapts to my workflow instead of forcing me to adapt to it.
Standard keyboards are compromise machines. They need to work for everyone, which means they're optimized for no one. A split mechanical keyboard with custom firmware can be whatever you need. Mute button? Done. Dedicated screenshot key? Easy. A layer that turns HJKL into arrow keys? Obviously.
For my work, which constantly shifts between design tools, code editors, and AI transcription services, this kind of customization isn't a luxury. It's a productivity multiplier.
What is the Sofle Pico?
The Sofle is an open-source split keyboard design. The "Pico" variant uses RP2040-based microcontrollers (the same chip in Raspberry Pi Picos) instead of the Pro Micro controllers found in earlier versions. This matters because RP2040s are cheaper, more available, and have more memory.
The specs:
- 60 keys total (30 per side)
- Columnar stagger (keys arranged in columns, not rows)
- Rotary encoders (one per side, endless scroll for volume or whatever you want)
- OLED displays (showing layer info, WPM, or custom graphics)
- TRRS connection between halves
- USB-C for connecting to your computer
Everything about the design is public. The PCB files, the firmware, the 3D printable cases. You can build the entire thing from scratch if you have the patience.
The Build Process
This is where the project got interesting. Building a keyboard from scratch involves several distinct challenges, each with its own learning curve.
PCB Manufacturing
The PCBs were the biggest unknown. I'd never ordered custom circuit boards before.
The Sofle Pico's Gerber files (the industry-standard format for PCB manufacturing) are available on GitHub. I downloaded them and uploaded to JLCPCB, a popular budget PCB manufacturer in China. Five boards cost about $15 including shipping. The catch? Three-week lead time.
Tip: order extras. PCBs can have defects, and you might make soldering mistakes. Having spares saves you from waiting another three weeks.
Component Sourcing
This is where costs add up. You need:
- Switches (I went with Gateron Browns, tactile but not clicky)
- Keycaps (PBT, DSA profile for the uniform height)
- Diodes (1N4148, 60 of them)
- TRRS jacks (for connecting the halves)
- Reset buttons
- OLED displays (128x32, I2C)
- Rotary encoders (EC11 compatible)
- RP2040 boards (WeAct Studio RP2040 or similar)
- Hot-swap sockets (optional, but I recommend them)
I sourced most parts from AliExpress. Patience required. Some things came from local electronics shops for faster turnaround on stuff I forgot.
Soldering
The SMD diodes were the hardest part. Surface-mount components are tiny. My first few attempts looked like abstract art. By the fortieth diode, I had a rhythm.
The through-hole components (sockets, TRRS jacks, reset buttons) were comparatively relaxing. If you've ever soldered anything before, you'll be fine.
Hot-swap sockets are worth the extra cost. They let you change switches without desoldering. When you're still figuring out your preferences, this flexibility is valuable.
3D Printing the Case
I printed my case in white PLA on a basic Ender 3. The files came from the Sofle Pico repository. Print time was about 8 hours per half.
The fit wasn't perfect on my first attempt. I had to sand down a few spots and adjust the PCB standoffs. But the result is solid and looks surprisingly professional for a DIY project.
Firmware
The Sofle Pico runs on QMK or Vial/VIA firmware. I went with VIA because it lets you remap keys through a GUI without recompiling firmware.
Flashing was straightforward:
- Download the VIA-compatible firmware from the repository
- Hold the bootloader button while plugging in USB
- Drag the .uf2 file to the mounted drive
- Done
The keyboard shows up in VIA immediately. You can drag and drop keys, configure layers, and adjust encoder behavior all through a visual interface.
My Custom Layout
Here's where the investment pays off. My layout has four layers:
Layer 0: Base QWERTY Standard typing. Nothing fancy here.
Layer 1: Navigation HJKL become arrow keys. U and I become Page Up/Down. This layer lives under my left thumb.
Layer 2: Commands Quick access to Cmd+C, Cmd+V, Cmd+Z, Cmd+S. Screenshots on 3 and 4. Play/pause and track controls in the top right area.
Layer 3: Window Management Dedicated keys that trigger my Yabai shortcuts. Focus window left/right/up/down. Toggle fullscreen. Float window. All through simple keypresses instead of modifier gymnastics.
The rotary encoder on the left handles volume. The one on the right scrolls through browser tabs.
And yes, I finally have my mute button. It's on the base layer, right under my thumb. One tap and I'm muted. One more tap and I'm back.
Cost Breakdown
Let's be honest about the money:
| Component | Cost (approx) | |-----------|---------------| | PCBs (5x) | $15 | | Switches (70x) | $25 | | Keycaps | $20 | | Diodes, sockets, jacks | $15 | | RP2040 boards (2x) | $12 | | OLED displays (2x) | $8 | | Rotary encoders (2x) | $5 | | 3D printing filament | $10 | | TRRS cable | $5 | | Total | ~$115 |
This doesn't include tools. If you need a soldering iron, solder, flux, and helping hands, add another $30-50 for decent equipment.
Could you buy a commercial split keyboard for less? Some, yes. But they won't have this level of customization. And you won't have built it yourself.
Was It Worth It?
Absolutely.
The keyboard itself is great. The split layout took about a week to adjust to. The columnar stagger felt strange for three days, then suddenly made sense. My shoulders sit wider. My wrists stay neutral.
But the bigger value is the customization. Every friction point in my workflow now has a solution. Mute for calls. Screenshot for documentation. Layer toggles for navigation. The keyboard bends to my needs instead of the other way around.
There's also something satisfying about building your own tools. I know exactly how this thing works. When something breaks, I can fix it. When I want to change something, I don't need to wait for a firmware update from a company that may or may not care about my use case.
It was a weekend project that turned into a week. But now I have a keyboard that nobody else has. One that was built specifically for how I work.
If you spend eight hours a day at a keyboard, that's worth something.
Interested in building your own? The Sofle Pico repository has everything you need: github.com/JellyTitan/Sofle-Pico