The Basics:

• STM32F072CBT6 MCU
• Hot swappable Kailh Choc sockets
• Magnetic Pogo connectors for modular extensions
• USB C 2.0 connectivity
• Integrated arrow keys
• 2.2" LCD Display

The Background:

The goal of this project was to build my own personal end-game split keyboard with all the bells and whistles I could think up. In reality, I know I'm fully addicted to designing custom keyboards now and this will only be the second in a long list of DIY keyboard designs, but for the time being, it has every feature I could ever want!

To start, I love macro keys, so this build features an almost full layout with a full row and column of extra macro keys.

Second, I didn't want to mess around with stabilizers, so the larger thumb keys and the shift, tab, caps lock, return, etc... keys are all 1.5u, meaning no stabs needed!

Next, I use my arrow keys constantly during my day job, so I wanted to find a way to seamlessly integrate a full set of arrow keys into the design. I was able to successfully tuck the arrow keys into the gap under my right hand so I can quickly and easily jump down to them for code navigation!

On the topic of frequent usage, I also use a numpad often at work. However, I wanted the plate and case to be 3d printable, so rather than integrating the numpad with the right split, I opted to add some magnetic pogo connectors so I could assemble the numpad separately and attach it when needed. An added bonus to this method, is I can add the same connectors to the left split and optionally add a numpad on that half too!

Furthermore, the numpad doesn't have to be a numpad, it could realistically be any extra switches or encoders you want. I designed an auxiliary numpad PCB, but there's nothing saying you can't design a custom extension to fit your needs!

The thumb clusters are also rather specific to my needs, as I'm a Mac user so I wanted access to a Cmd, Ctrl, Option and Space on each thumb. In the firmware, I've configured the command keys to actually be layer shifts, so for most keys I can perform modded actions (like copy/paste, undo/redo), while the remainder of the keys stay open for custom macros.

Lastly, I added 2.2" LCD displays to each half and per-key LED lighting, because... well just because.

In conclusion, this might not be the dream keyboard for everyone, I understand most people prefer to use more layers as opposed to more keys, but I'm not most people. In the end, this keyboard turned out awesome and has instantly become my daily driver! I will continue to update this post with new pictures as I continue to build out the case and firmware!

Left Half:

https://www.pcbway.com/project/shareproject/Module_Split_Mechanical_Keyboard_Left_Half_f05e1cac.html

Numpad:

https://www.pcbway.com/project/shareproject/Modular_Split_Mechanical_Keyboard_Numpad_5ea6c1e4.html

Schematic:

https://github.com/modern-hobbyist/aesir/tree/main/hermod

3D Printed Parts:

https://www.printables.com/model/1303280-custom-split-keyboard-case

Check out my YouTube channel for the build video!

https://www.youtube.com/modernhobbyist