When [daniely101] wanted a split keyboard, he decided to build his own. It wound up costing $25 to create a wireless board with no custom PCB required. Each half has its own microcontroller, and the whole thing connects via Bluetooth. While we don’t mind making a PCB, we can appreciate that you could change your mind easily with this wiring scheme.
The 3D printed case holds the keys, and then it is just a matter of carefully soldering the keys to the microcontrollers. Of course, each side also has to have its own battery. The ZMK firmware is split in half, one part for each side of the keyboard. The nRF52840 CPUs have plenty of wireless connectivity. The keys are set in rows and columns, so the amount of soldering back to the controller is manageable.
While we applaud the wireless design, it does seem odd that you have to charge both halves and turn them on and off separately. But that’s the nice thing about a design like this — you could modify the design to not have a split. Or, you could allow one flexible wire pair to run across for power. Of course, you could modify the layout, including adding or deleting keys.
You might consider adding a pointing device. At least you don’t have to pull out a saw.
For a lot of these projects, the PCB is created just because people like making them. I get it, sometimes it’s fun and it feels a lot nicer. But usually if you do a one-off you just bend some solid-core wires and do point-to-point. It ends up being a lot faster than fiddling around in CAD, and usually the CAD needs a revision and you end up bodging some wires anyway
True.
But using CAD and making a PCB also means that what you make will be quite a lot more reliable in the long run, at least it’s by far not so fragile as a point-to-point wired PCB. And you can put your design on Github so that others might be able to use it as well.
Imo two very important pros.
I’m not sure you can really say a PCB will be more reliable as so much of surviving the real world is the mechanical design around the components – sometimes the PCB can be a core part of that, but others all the PCB does is hold the pad that will ripped right off it as soon as a bit of torque is applied to the cable plugged into that socket etc.
In many ways the point to point manual wiring is just as accessible if not more so than a PCB design that most folks would have to send off to the fab house to create as well – so hardly a downside for replication of your work (assuming you actually document and publish the wiring diagram).
NB not down on PCB at all, convenience factor is huge, speed of assembly especially if you are a wizard with the SMD and reflow profiles (etc) is orders of magnitude faster, and gets even crazier with a Pick’n’Place, almost certainly still faster if the PCB is all through hold components to hand solder too..
Point to point wiring with solid core and diodes is how I’ve done my hand wired keebs.
It certainly was fast, but I also have not attempted any PCB design, so hand wiring was the only realistic option for me.
One day I’ll be actually have hardware skills… (Been saying that for about a decade)
Hmm….
“I wasn’t sure if it could be shipped to me, since all the sellers were located on the opposite side of the continent”.
Then proceeds to buy some unnamed dodgy looking clone with probably a cloned CPU that doesn’t have the same specs as the real thing, let alone having all of it’s listed peripherals, from the opposite side of the world through AliExpress… :P
I mean, it’s fine to buy such a clone through AliExpress, but “I wasn’t sure if it could be shipped to me” is a real weak excuse for choosing some AliExpress clone just because it’s so much cheaper. At least be honest about it. ;)
I buy lots of stuff through AliExpress, just because it’s cheaper. Just last week I bought six FT231 chips through AliExpres. Because they cost me €20.32 including shipping for €7.75. The only “Western” sources are Mouser, where six would have cost me €43.21, or Digikey, where they would have cost me €30.30, or Farnell, who doesn’t want to sell to me as I’m not a business, but would have charged €34.98.
The issue is the shipping costs. Mouser: €20.00, Digikey: €18.00, Farnell: €14.99.
€20.00 for a frigging 5cm strip of SMD IC’s!!??? In a €0.50 envelope??? Sent from my neighbouring country (Germany)??? Are you serious?
Hey, ok, I receive it 3 days after ordering, while AliExpress takes 10 days or so. But still, the distance is much shorter. I can’t understand how it can be that they are so inefficient that shipping costs twice to three times as expensive as the much, much, much longer distance from China.
Oh, and the funny thing? Mouser Netherlands is in Eindhoven, Netherlands, where I live. But I can only choose “International” or “Worldwide” shipping. Come on! Send it to me via regular post, it costs €3.95, not €20.00!
They don’t want small orders and apparently it works.
Farnell used to have free shipping. Order at 17.00 and you would have it the next day around 12.00. But no free shipping anymore, and next day only if you’re very lucky. I mostly use TME or Mouser for parts. Mouser when I’m above the free shipping threshold, TME otherwise, they have more reasonable shipping costs.
Mouser Netherlands is just an office I believe, they have no stock…
Mouser having only an office in The Netherlands – yeah, I figured such.
The problem originated from me making an SMD-based design that I wanted to be easily soldered. It has a USB controller, and I used a CP2102. It works great, but it’s a tiny QFN28 chip and is hard to hand-solder. So I searched for something with pins sticking outwards and found the FT231. But then found out that hardly any electronics provider that sells to consumers carries it. FTDI doesn’t sell directly to consumers, and so I got into this mess.
Basically, my only serious options are Reichelt, TME, and since a few months RS. But none of them carried the FT231.
Hey, creator here. Just to clarify, I haven’t dealt with sellers outside my country before, and it didn’t make sense to buy from an unfamiliar place at a higher price when I could get the board cheaper from a source I already know. The whole point here was building a budget keyboard, and time wasn’t a factor.
I also searched for the actual nice!nano on AliExpress , spoiler: it’s not there. So I went with a compatible alternative that works well for this project.
Plus, I talked with Nick Winans, the guy behind the nice!nano, and he confirmed the schematics, diagrams, and bootloader files(which are public btw) are free to use without restrictions. Using a compatible board for a hobby project is totally fine.
Another reason for going with AliExpress is that anyone who watches the video can easily order all the parts from there at the same time, no need to hunt for the original nice!nano, which isn’t available everywhere. Not everyone watching will be able to order the original board anyway, since it’s not sold on all continents and there are other barriers.
Bottom line: this was a practical choice to keep things affordable, simple, and accessible for a personal project.
The keyboard is nice. But I really prefer to not have it in two separate parts, but have it joined together in the middle. Because I am always moving my keyboard around on my desk, and don’t want to be moving TWO half keyboards around on my desk. ;)
One day, I will create my own custom tailor-made keyboard.
With genuine curiosity: why are you always moving your keyboard around on your desk?
could use a pair of esp32’s and use espnow to wirelessly signal the other half to come out of deep sleep
Does using matrix implies some ghosting and a limited combinations of keys that could be pressed at the same time ?
Not necessarily, since diodes are a thing.
No, it’s scanning at high freq.
It’s not the high frequency scanning that alleviates the ghosting issue, it’s the diodes.
If you there are no diodes and you press two keys on both adjacent row and column it doesn’t matter how fast you scan you won’t be able to determine which keys are being pressed. And the diodes allow the controller to identify every key being pressed even if the scan would happen at a glacial pace, it doesn’t matter.