Version 2 was meant to be an drastic improvement over version 1, mainly to solve a lot of the issue I found in my daily usage, and to also experiment with new ideas.

The main issue with version 1 was the layout. The number row is still too far for my small hands, and reaching them often means that I have to move my hands, which is not ergonomic and efficient in any way. I also used the Cherry MX pitch (19.05 x 19.05) instead of Choc pitch (18.5 x 17.5). This meant that I had to stretch my fingers further out in order to hit the keys. The last problem is that my short pinky can't comfortably hit the p and q keys, as they are on the a and ; keys when fully stretched.

To resolve the issue, I first removed the number bar from my layout, both in firmware and physically by removing the switches. The now homeless numbers and related keys on the other layers are forced to move. To tackle this, I cram some of them in the raise and lower layers, and I have to dedicate a whole new layer for miscellaneous function keys. I also tried out and got used to the Mod-Tap feature, which allows me to put some keys on the thumb clusters. To solve the last issue, I moved the pinky column down by 1 whole key (which turned out to be great).

The second issue is related to portability. As I bring my keyboard with my laptop, setting up the keyboards (plugging in the cables etc.) takes up quite some time. So I began to look into wireless solutions, and I put a bluetooth and a nrf24 wireless module footprint onto the PCB. I didn't have the wireless design ready to go yet, but this board was also meant to be an experimental version, so it doesn't matter that much if the design is not perfect. I also put a CR2032 coin cell holder hoping that I can use it for power when in wireless mode.

The last things I added are a NeoPixel RGB LED for layer and debug information, and a reset button. On version 1 there's no physical reset button, and every time I flash the firmware I have to find some metal to short the reset and ground pins :).

The last issue was the underside for the PCB. In version 1 the result was Ok but not great. In version 2 I tried to stack 2 PCBs together for one half. This way the switch pins are completely embed in the PCB, but it also meant that soldering and making sure the soldered connection works well can be difficult. But if we ignore the rare connection issues the underside now is completely flat.

The gerber files for version 2 is in a separate folder (I still need to get used to version control with external-software-managed files), and there's a new version undergoing design.

The keymap can be found here. Only the difference in the layout of the symbols are worth attention (on the lower layer). With the exception that I put the shifted symbols of the base layer (i.e. <, >, :, and ?) on the lower layer on the same position to help me transition to using only the lower layer for symbols, all the other rows have a fixed pattern. The keys for the pinky and ring fingers on the same row are in one pair, same for the middle and index fingers. Some of the pairs might not have meaning for other people, but those are based on the meanings in Vim.