devkybd - split ergo mechanical keyboard

[redesigndavid]

Hey guys, I made a few split ergo keyboards for myself too. I made my first one using a teensy and brown switches. Everything is hand soldered. I designed the templates for the switch placements. It's ortho linear like most ergo keyboards, but I didn't have the extra inner column. The F and J keys are on the second column from the inside. Here's an image of my first keyboard.

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I used that keyboard for something like 6 months. And then one day I saw that massdrop had gateron keys, and I thought I should get some clicky blue switches and make a keyboard out of them. I found a low volume pcb manufacturer in China, tried my hand on designing pcbs. That went pretty well too. I used this baby for a little under a year.

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One day I was on the way to the toilet of this mall and saw there was a computer shop in the most unlikely of places, and on display is a matias keyboard. I shouldn't have tried using it because since then I've been dreaming about making a split ergo keyboard out of it too.

But this time, a few of my office mates want me to make keyboards for them too. That made things a little bit tricky. One of my colleagues who requested for a keyboard works in the dark and so he needs a backlit keyboard. But I wanted to use matias switches on my new keyboard and no matter what I did, I couldn't find keycaps that could let the letters shine through when backlit. The solution was of course to make the footprints on the pcb cherry and alps compatible.

I really liked the 7 columns on my keyboard but the truth was I don't even remember what I programmed for the outer most columns. Since I hardly move my hand left or right when I type using my keyboard, my pinky has become lazy, so like a couch potato it prefers to spend its days on the home row. My index finger though could still reach in for an extra column, so in the new design, I'm moving the outer most column to become the inner most one.

When I designed the first pcb for my black keyboard, I was still thinking of using wires to connect to my teensy, not realising I could solder my teensy to the board directly. I'm doing that on my new keyboard.

The keyboard design uses a 5 by 7 grid, which means I needed to have 12 wires to connect one half of my keyboard to the other half where the teensy is stored. To accomplish this, I used an hdmi chord, stripped it, and connected the inner wires to each half of my keyboard. This is more tedious than it sounds (it takes alllll day!!!!). With the new keyboard, I'm using hdmi smd connectors to connect each half of the keyboard to each other.

I also want to use less table real estate, and a chance to tent them using height adjustable stands.

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The hdmi connectors would be surface mounted on the backside. The pinholes under the hdmi connectors are there as a backup just in case the connectors don't workout as I expected.

To keep costs as low as possible, the pcb's design let's it be used as either the left or the right side or with matias/alps or cherry switches without flipping or rotating anything.

[webwit]

Looks very promising!

[KRKS]

I think it would be better if the bottom three keys would be shifted to the inside like in the handwired one. But besides that, I like it.

[armatus]

it has teensy on both sides?

[Ray]

The keyboard design uses a 5 by 7 grid, which means I needed to have 12 wires to connect one half of my keyboard to the other half where the teensy is stored.

So only one side has a teensy, the whole matrix is extended in parallel to the other side.

[spindle]

Looks similar to my old build .

You might be interested to check out the firmware I used for my build. You connect the halves with only 3 or 4 wires (so you can use TRS, TRRS or USB) and you can connect the USB connect to either half or use them indepently. Also, you can use pro micro's which only cost ~3USD each.

[Morituri]

how is it to type on the columnar stagger? Is it much nicer? How long does it take getting used to? And do you miss the spacebar? Well, more to the point, do you actually physically miss the space key on your board?

I've been considering keyboard layouts, but I'm sort of conservative about layout, at least by default, and don't mind the desk space of a big board. So mostly I've been considering extensions or additions rather than rearrangements.

[redesigndavid]

Looks similar to my old build .

You might be interested to check out the firmware I used for my build. You connect the halves with only 3 or 4 wires (so you can use TRS, TRRS or USB) and you can connect the USB connect to either half or use them indepently. Also, you can use pro micro's which only cost ~3USD each.

How I wish I've heard of that earlier! How does it compare in terms of refresh rate? And if there is a difference, is it obvious?

how is it to type on the columnar stagger? Is it much nicer? How long does it take getting used to? And do you miss the spacebar? Well, more to the point, do you actually physically miss the space key on your board?

I've been considering keyboard layouts, but I'm sort of conservative about layout, at least by default, and don't mind the desk space of a big board. So mostly I've been considering extensions or additions rather than rearrangements.

I think it helps that I learned to touch type early so when I started using my keyboard I only had trouble with the bottom row. I got c and v, b and n, mixed up. 2 to 3 days later, I was very comfortable. And when I have to switch back to the regular layout board, I have more trouble with the caps lock/ctrl swap than the stagger difference. Do I miss the space bar? Not at all.

[spindle]

How I wish I've heard of that earlier! How does it compare in terms of refresh rate? And if there is a difference, is it obvious?

The serial it uses runs at about 40k baud, and for each scan of the matrix it transmits 48 bits (4 bytes for key matrix, 1 byte for LED state, 1 byte error check), so it takes about (48/40000)=1.2ms. So if you set the USB poll interval to 1ms, you'd probably get about 500Hz refresh rate. And in practice I never noticed the delay.

If you're worried about refresh rate, it also has i2c support which has a baud rate of >100k baud, so you should be able to get 1000Hz refresh rate.

[redesigndavid]

I was able to finish the project about a year ago.

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To be honest, I nearly gave up on this project. The hdmi smds were a pain. It didn't help that it was my first time working with surface mounts as a whole. I discovered something very important. "Surface mount" meant the pins had to touch the surface, hence the name. Apparently, the legs of my hdmi ports were just a little taller than the thickness of my pcb. This discovery came only after the 5 broken hdmi ports and pcb boards. On that sixth attempt, I noticed a sliver of light from beneath the port, less than 0.1 thick. The height of the legs of the hdmi meant it was propped up a little bit.

I used a nailcutter to cut the legs shorter, and everything worked. It took a while for me to write this update because I was afraid I might get banned because of excessive use of profanity. I'm calm now, it's been a while.

That was not the end of my worries though. The pins from each side of the hdmi cable don't have a direct mapping with each other. Some of them twist. There are online references, but either I read them wrong or the reference itself was wrong. I soon discovered a lot the pins I had that connected to the other side wasn't working. I used the first 9 pins according to diagrams online. So to anyone who wants to attempt to use hdmi to put together the two halves of a keyboard, you've been warned!

I had to order new PCBs. This time I left a gap between the pins that connect to my teensy and the pins that connect to the hdmi. I would then solder wires between them. That worked, but what a hack!

The moral of the story is to use the method that spindle was describing. In fact, maybe next January, when my heart and my pocket has fully recovered, I would attempt another build using TRS ports.

Worth noting, a friend on mine requested to have a hori hayabusa joystick next to they keyboard, so he can play games with it. So I built one for him too.

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