Author Topic: Low Profile Wireless TKL Build  (Read 637 times)

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Offline ice9js

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Low Profile Wireless TKL Build
« on: Fri, 13 November 2020, 07:56:54 »
Hi everyone!

So for the past 6 months or so I've been working secretly on a little project of mine to possibly replace my old dinovo edge keyboard.
It looks to me like there's a pretty big void in high-end low profile keyboards which I'd maybe like to fill some day so I thought I'd maybe gather some feedback before committing to any design and getting the parts made - I'm trying to be economic.

Features I'm aiming for:

- Low profile: The current design is for a total thickness of 15mm with keycaps included. (11mm body only).
- All aluminum chassis
- Wireless: I've decided on Nordic's nRF52840 which supports Bluetooth 5.2 (and has a few other tricks up its sleeve as well :))
- USB-C for charging or wired use.
- Capacitive slider: I like the function of rotaries, not so much the look. Controlling volume for a start but I wonder if I can also make it work for doing stuff like controlling sliders inside software light Lightroom or DAWs - not a priority right now though.
- Macro row: Mostly to offset, the extra spacing around the slider on the other side.
- Top mounted plate/PCB: I was initially thinking of just milling out the holes from the top enclosure but now I'm a bit worried about the wireless reception - there isn't enough room inside the case for a proper slot antenna implementation and an external one isn't an option. So the plate would have to be non-metal.

The main questions I'm struggling with now are:

Choosing the appropriate switch system

So far I've been hoping to use Kailh's Choc (v1) switches with their biggest obvious drawback so far being the lack of keycaps. So my idea was to use these caps for the initial prototypes although they're not compatible with the Choc stabilizers - nor can I see any other stabilizers I'd be able to get that work with the switches.

An alternative would be to use their v2 Choc with cherry stems, though that'd probably still require custom molds in the end as I didn't see any with a profile lower than ~6-7mm (I'd really like to stay around ~4).

Choosing the right layout

I'm currently deciding between two layouts:

- A classic TKL
- Or a narrower variant

I'm personally a fan of the latter, having the page-up/down buttons closer and I can't remember the last time I used the arrow keys.
It'd also help on cutting down on the increased width from the slider/macro row (regular TKL case would be ~425mm wide, one row less gives ~406mm).
Curious what other people think.

I'd like to eventually make a matching numpad as well.

Where are things at currently

So I started by writing the firmware last spring. It's custom as ZMK wasn't a thing back then, but I'm still planning on open sourcing it once I'm done.
Core functionality is pretty much fully implemented. I've held off for stuff like LED animations etc. until I have a proper board to test with.

I have a ready PCB design - though obviously I'm holding off on ordering the boards before deciding on the layout. And I'm starting to have second thoughts about the Chocs :(
I'm wrapping up the design of the TKL case, but the more I think about it I think I'd like the narrower layout more.

Help me draw the line and I promise you some nice pictures next week :D
« Last Edit: Fri, 13 November 2020, 08:56:04 by ice9js »

Offline ice9js

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Re: Low Profile Wireless TKL Build
« Reply #1 on: Sun, 22 November 2020, 11:02:14 »
Standard TKL it is.
Unfortunately I made the mistake of using the default 19x19mm switch spacing and eventually I figured I should probably stick with 18x17 which seems to be the standard for Chocs, to better serve people already invested in them.
Besides, over the width of the entire layout, adjusting the spacing saves as much as removing an entire column with the normal spacing.

Anyway, I pretty much wrapped up the design on the case. It ended up being 12mm thick without keycaps, so the total height should be around 16-18mm.
The whole thing is still pretty large, so to keep it visually smaller I went with these 'winglets' on each end to isolate the macro keys/slider area with the added bonus of the keyboard to appear as if it's floating when looked at from the right angle.
Excuse my poor render quality - it must be like 15 years since I tried to render anything... For now I'm not really willing to spend much time on that, it's really just to give a decent overview of how things will look.


Now, I'll have to update my PCB to match the new spacing and hopefully should be on my way to ordering a prototype soon after.