When it comes to building a split keyboard, you have a lot of options when it comes to the cable. Many will use a standard 3.5 mm TRRS cable, and others might use something more esoteric like RJ-45 to run between the halves. This only works if you’re using two controllers; if you only want one controller, you have to pass the matrix from one side to the other, which typically requires more than the four wires offered by the aforementioned choices. While rummaging around, [Joe Scotto] found a VGA cable and thought, why not use that?
This lovely Barbie-themed peripheral is a split version of an earlier board he built called the ScottoFly, which is a monoblock split with a void in the middle. As with that one, this is hand-wired using thicc brass insulated with heat-shrink, uses a solid 3D-printed plate, and a printed case. And like a madman, [Joe] coiled the cable.
Unfortunately, this proved to be problematic in the wire breakage sense, or so he thought. The real problem turned out to be that the middle row of pins on a VGA connector all act like ground, so they can’t be used to pass rows and columns. However, there were still enough viable pins to send the 4×5 matrix across. Be sure to check out the build video after the break.
Via KBD #103
Why would rj-45 be esoteric compared to vga db-15? Only the name would throw most but the connector Is easily tested and available and easy to make or purchased. My Walgreens sells cat5 Ethernet cables but not VGa db-15
Like the ⌨️ coverage overall. More chording keyboards soon?
VGA uses DE-15. DB-15 would be a much wider connector.
Yes, DB-15 we’re often seen on sound cards as joystick/controller ports but I used to also see them on old (HP) network cards too as AUI ports for Ethernet transceivers which enabled a single card to support multiple media by just changing the transceiver out…10baseT with RJ-45 connectors or coax (10 base 2 or 10 base 5) with barrel connectors.
Akshully, that’s a DA-15: https://en.wikipedia.org/wiki/D-subminiature
VGA cable connectors are a actually HD-15, not DB-15. HD stands for high density… they fit in the same footprint/shape as a DB-9 connector.
I just looked up that he could have used charlieplexing to read the keys since he is already using a diode for every key. That would have used only 5 pins (I think) for each half.
The retro look of a blue VGA cable is hard to beat on the other hand so the need for a different multiplexing is there.
I guess I am old then, because PC99 color coding doesn’t seem very retro to me, but then I’d been using PC for 15 years by then, and started with CGA/EGA.
It reminds me of hideous HP and Gateway boxes running Windows Me
https://en.m.wikipedia.org/wiki/PC_System_Design_Guide
HDMI or USB-C, or even Mini Displayport also options.
My only real problem is how it is (isn’t) color matched. VGA isn’t very aesthetic unless you are going for beige-box “cyberdeck”.
Pardon me for pointing out a 4×5 matrix could fit in a Serial 9-pin, which coincidentally has the same D-Shell.
This however is a hack, kudos.
Todo: tag this post Circuit Sculpture and add a picture of the wiring.
Good thing this isn’t a consumer product. I’ve already seen too many cases of somebody, when faced with a device with an RS232 port and no corresponding port on the computer, tracked down a DE9 to DE15 adapter meant for EGA monitors, and plugged the serial port into a VGA port. This never ended well.
I don’t get it. Why people doesn’t use usb Type-C?
> The real problem turned out to be that the middle row of pins on a VGA connector all act like ground.
Bad VGA cable bad!
A good VGA cable does not bridge the RGB shields together. Pins 6, 7, 8 and 10 shouldn’t be short circuited.
-> https://en.wikipedia.org/wiki/VGA_connector
A commonly used standard computer connection is “esoteric?”
Also, why beat around the bush? Those aren’t Barbie colored, it’s trans pride colored.