Bireme - A Wireless Ergodox-inspired Split Keyboard

Introduction

The Bireme has been a passion project of mine that was heavily inspired by two great boards: The Ergodox and the UniGo66. The Ergodox Infinity is the keyboard that got me into custom keyboards and unique layouts. I joined the community towards the tail-end of the Ergodox's peak as the go-to "show your friends how weird Keyboards can be" DIY keyboard, when Massdrop would regularly bring back the Ergodox Infinity drops. Over time, I've watched as Ergodox interest has waned, with Ergodox keycap kits being harder and harder to hit MOQ. Even though IC and Ergodox EZ were continuing development the board in their own ways (hot swap, per-key RGB, underglow), they stuck to the same design principles of the Ergodox that seemed to hold it back:

• The thumb cluster was too large, unwieldy, and mostly useless
• Lack of high end/interesting cases.
• Interconnecting cables are a nuissance on your desk or when you're on the go.

To be honest, I myself had moved on and have been typing on Boardwalks for more than a year now. When the UniGo66 IC and GB launched, I immediately thought about how it solved the above two problems, and the interest from the community supported my theory about why the Ergodox had become passe. While I really admire the UniGo66 for its creativity and stellar mechanical quality (and to be transparent I was all over that GB like stink on cheese), I had a feeling I would really miss the Ergodox' columnar stagger. I started tinkering in Solidworks to see if I could mash the two together to make something greater than the sum of its parts. I wanted to design a keyboard that would be the missing link between high end customs and ergonomic typing. A kind of "Metal Gear," if you will.

Shoutouts

I'd like to thank alex_at_panc, dollartacos, and un_related for helping with the development process. I wouldn't have been able to get here without the support of these three gentlemen!

Gallery


Specs
Electronics:
• Bluetooth 5.0, with supported wired mode as well
• Internal 3000 mAh LiPo battery that can be charged by USB
• Kailh Hot swap sockets, with via-reinforced pads
• Powered by QMK

Mechanicals:
• CNC Aluminum case (20mm thick), powder coated by /u/alex_at_panc
• Top mounted 5mm Aluminum or brass plate
• Acrylic or 3d printed bottom

Tentative Pricing

CNC Case + Electronics + Stainless steel plate + Powdercoating: $300
Brass plate: +$50
Extra set of PCBs: +$100
Tented 3d printed bottom: +$10

2019-05-26 Update: Prices have been reduced due to switching to a new manufacturer with an even better reputation. This new manufacturer has more experience with keyboards and has the right equipment to produce what I want, which has led to the inclusion of the 5mm plate as part of the new reduced produced price point.

Ongoing Development
This is where I’m going to need everybody’s help. This project is definitely still fluid and between optimizing costs and redesigning the damn electronics every 2 weeks, there’s time for plenty of input from you guys! I’m excited to expand this to the wider community and get more feedback about how to move forward. If you're interested in this project at all, please fill out the survey and let me know where we should take the Bireme!

Electronics
The first iterations of the keyboard were meant to use a modified Mitosis/Redox Wireless design. That is to say, it would have featured the Waveshare Core51822(B) modules, coin cells, and the use of a USB receiver that is tethered to your PC. I loved this design because of how simple it was, and the option to sell kits unassembled and have users solder the parts themselves. However, the coin cell taking up space on the PCB was a major challenge, as well as having to flash the modules using an ST Link debugger. As the design started to evolve and I wanted to make the product feel more premium, I made the decision to shift to a new BT implementation with the features listed above in the specs.

I am currently redesigning the PCB with the help of an unnamed contributor who wishes to remain anonymous for now. I'm hoping to have PCBs ordered this month and assembled and tested. I'm going to be honest, I'm decent at PCB design but flat out garbage at programming so firmware may slow me down, but it's coming along at a fair pace and I want to make sure I do it right the first time.

I'm currently also looking for the largest, thinninest LiPo battery. There will be quite a bit of space for batteries but the limiting factor is thickness. The thicker the battery, the thicker the case. So far, it looks like around 1000 mAh is about the largest single battery with a thickness that's safe for the case. There's enough space to fit 4 of them inside though, if we wanted to go wild.


Update 2019-05-26: Left PCB is done, working on right side PCB now. Have also sourced a massive 3000 mAh lipo battery that will fit in the case

Mechanicals
The general case design language is frozen and I don't want to **** around with it anymore (seriously, it’s gone through enough revisions). However, I’m still working out the details of support components, namely the plate. I will be offering both brass and stainless steel versions of the plate, but I'm looking into offering a 5mm plate, or even an integrated plate, depending on how many people are interested.

Update 2019-05-26: A 5mm aluminum and brass plate option will be the two options for plates now, even at the reduced price point.

After printing the prototype and throwing some caps in the case, I'm also not very happy with the gap between the caps and the bezels. Would you be supportive of shrinking this distance or would you rather error on the side of caution?

Update 2019-05-26: I have shrunk the gap by 0.5mm. Waiting on a resin printed prototype to get a higher accuracy comparison.

Low Cost Alternative
Is there enough interest in the layout itself to warrant releasing PCB files for a wired version of the board, with acrylic/3d printed case files? I'm happy to whip up a DIY wired PCB that uses TRRS jacks and Pro Micros on each side. I know not everybody is ecstatic about dropping $300+ on a keyboard, or people would want to try the layout before committing to something more extravagant.

Update 2019-05-26: Due to the amount of time the Bireme is taking up for me, I have decided to put the low cost alternative PCB aside for now. I will 100% be releasing gerbers for a pro-micro DIY wired version in the future but right now I don't have the bandwidth to design another PCB.

Survey
I'm happy to carry on dialog and discuss the design with everyone here but it's way easier to digest data when it's tabulated in some format. Please, if you have a chance, go through this survey and let me know your thoughts! If you want to join the mailing list to get my updates first, there's an option to leave your email address!

https://forms.gle/oXn9vuA9b7qxfWVD7