deskthority

Issue #62 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is available:

Issue #63 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is out:

Issue #64 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is out:

Issue #65 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is out:

Issue #66 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is available:

How did this blurry rubberdomes get to the cover? History is being written one hour's drive away from my home so my priorities have changed this week. Regardless, here are some projects I thought would be worth sharing.

Issue #67 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is available at:

Worst. Cover. Ever.

I don't know about that. The connotations are strong in this one.

Oh! :O Context, aye.

Still the worst cover ever, but for a profoundly bigger, deeper, and truer meaning of worst.

Just to make it clear, I live little more than an hour's drive away from the Ukrainian border where Russian war criminals keep killing civilians. (I mean, not on the border but in Ukraine in general.) Consider supporting one of the well-known charities in the region. Here are my suggestions. Money landing on my PP account will be transferred to them too, just like last week.

Btw, I was at the border this weekend and charities, local municipalities and civilians do a pretty great job. This page is powerful too.

Issue #68 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is available at:

Issue #69 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is available at:

Issue #70 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is available at:

Issue #71 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas is available at:


In addition, the newsletter has now 2,000 subscribers which exceeds Mailchimp's free plan. Check this week's editorial if you'd like to help. Or here is a direct link.

And here is Issue #72 of Keyboard Builders' Digest, my weekly selection of DIY keyboard projects, tips and ideas:

And here is Issue #73 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas:

And here is Issue #74 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas -- this time with some original longer format articles about e.g. the PRK firmware or the LDSA keycap profile:

Issue #75 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas is available:


Hey, did you know you can handle 200-300 switches with a simple Pro Micro? I cover the 200-switch solution in my write-up titled The Japanese duplex matrix

Oh! That's actually rather neat. Kinda makes me want to try a Nice!nano all the more now. Only drawback is the matrix itself has to be designed with this shared column / alternating diodes in mind, so no using stock PCBs.

Speaking of PCBs: got an example of one to share? Your diagrams understandably deal with the trivial 3 × 2 case, but a visual of what a 60% or greater really looks like with this arrangement would be illuminating.

Is the Japanese duplex matrix truly NKRO?
In 3.3V application it's probably not an issue though. A generic 1N4148 diode has a forward voltage drop of around 1V so I guess by the time the signal makes its way through 3 diodes it's low enough that the GPIO registers it as off.

With the mega 32u4 and 1286 on their way out this definitely makes the little nRF chips a lot more appealing.

Also neat that there's a name for the overlapping rows; I thought I came up with something for once :/

Muirium wrote: ↑

25 Apr 2022, 18:30

Speaking of PCBs: got an example of one to share?

I was fascinated by the theory but haven't tried it yet.
As I can see, this matrix style was picked up in Japan late 2018, early 2019, and many projects from that time have disappeared from the net.
On the other hand, members of the Japanese community tend to keep their PCBs closed-source in general.
So e.g. the Angel64, which I guess uses this matrix, has only a build log: https://kakunpc.github.io/buildguides/angel64/
I'm not sure this helps.

Diagonals to dizzy the mind! Well, mine at least. It’s pretty busy as you’d expect.




Can’t say I can follow it (without pulling out the tracing tools, which I shan’t for once).

Jsheradin’s point about ghosting is noteworthy, however:



Looks to be 2KRO. That third key triggers a phantom fourth.

Issue #76 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas is available:


Follow-up to my Japanese duplex from last week: I'll have to update that post with some explanation why and when the voltage drop across three diodes may take care for ghosting.

On a similar note, did you know you can actually handle 380 switches with a simple Pro Micro? This time I cover a new arrangement with ghosting in the focus: Square or round-robin matrix.

Muirium wrote: ↑

25 Apr 2022, 21:07

Looks to be 2KRO. That third key triggers a phantom fourth.

I'll have to update that post with an explanation.
By carefully choosing diodes (voltage drop matters a lot!) this should work with both RP2040 and ATmega32u4 without ghosting.
Or if you have tons of 1N4148s at home you can use two of those for each switch with the atmega.

Issue #77 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas is available:


With an improved square matrix: up to 380 keys with a Pro Micro -- with less diodes.

Issue #78 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas is available:

Issue #78 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas is out:

Issue #80 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas is out:


If you like to win free stuff, check out this week's editorial for some goodies.

Man, that FLS is awesome looking!

Issue #81 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas is out:


Again, if you like to win free stuff, check out this week's editorial.

Issue #82 of Keyboard Builders' Digest, my weekly roundup of DIY keyboard projects, tips and ideas is out:


Again, if you like to win free stuff, check out this week's editorial for a super rare KBD.NEWS metal artisan keycap offered by metalkeyboards.no.