About the column wiring: You can buy ptfe sleeving and single core uninsulated wire. PTFE won't melt. Here's one example, it comes in a bunch of sizes and usually in 5 m lengths.
Really great write-up btw!
My First Keyboard Build
11–20 of 82 posts
Re: My First Keyboard Build
#12A witty and self-deprecating write up of a first dive into hobby hardware - and a great result.
I would also check out plover - steganography for the masses.
Excellent - keep it up!
Re: My First Keyboard Build
#13About the column wiring: You can buy ptfe sleeving and single core uninsulated wire. PTFE won't melt. Here's one example, it comes in a bunch of sizes and usually in 5 m lengths. Really great write-up btw!
Awesome - I'll definitely be using that for my next build! Thanks man!
Re: My First Keyboard Build
#14'Tis pity. There's really no reason to go to all this effort and expense and not split the spacebar into left and right buttons, not add any other thumbable modifier keys, and worst, include neither a pointing stick nor a thumbable trackpad.
Re: My First Keyboard Build
#15'Tis pity. There's really no reason to go to all this effort and expense and not split the spacebar into left and right buttons, not add any other thumbable modifier keys, and worst, include neither a pointing stick nor a thumbable trackpad.
Hah, it's still early days man! This is the first build of many to come. As I stated in the blog post, this build was just to see if I was capable of doing it since most of the skills I didn't possess before starting the build. Now that I know how to do this sort of stuff I'm definitely going to be exploring all the things I can do in the future.
Re: My First Keyboard Build
#16Excellent build quality, but I was surprised by these two statements on things you need:
A decent soldering iron. You will thank yourself later. Also note: you will burn yourself many times throughout the build. Might as well do it with a fancy iron!
LEADED SOLDER – I started the build without leaded solder and oh dear…
Well, even with a really crappy iron, as long as the tip is fresh, you shouldn't have a problem. Most people's problems with soldering come from not having the tip wet enough and not using enough solder, thereby not making enough contact with the wire and not putting heat into it fast enough to get that specific location hot before the heat conducts away into the rest of the wire.
Remember, the entire reason we're using the wire is because it's an excellent conductor. For that reason, thicker gauge wire is also going to be more difficult to work. And the only reason to use larger gauges of wire is to support more current. Keyboards run on extremely little current already. You probably could have done this with magnet wire and been fine (though I wouldn't recommend it, magnet wire is difficult to work for different reasons).
So crank up the heat. Get it into the wire as fast as possible. Lead-free solder generally needs higher heat than leaded solder anyway. Apply the solder, apply the wire, then wait a second before removing the iron, because you also have to heat the wire you're pushing in. Soldering is a chemical bond, the metals physically mix, and you need to get them up to the right heat to do that.
And keep it steady, any movement while it is cooling will create microfractures in the solder joint.
Re: My First Keyboard Build
#17if anyone doing a hand-wired build has a better/more efficient method of making the cables for the columns, please let me know
Use self-fluxing enameled wire. It's insulated with an enamel that melts/converts into flux at soldering temperatures, so all you need to do is wrap a turn around the post of each switch contact for a column, then add solder to complete the connection. Some are sold in a convenient pencil-shaped dispenser (http://en.wikipedia.org/wiki/Wiring_pencil ).
I've always wanted to build a keyboard for fast typing, with ultra-light low-travel leaf-spring switches that have a more "bouncy" feel. When trying to type at 160WPM+ it matters far less what kind of sound or tactile feel the keys produce as you care more about the key actuating immediately when hit and providing some spring action to help the finger back up afterward. A leaf-mounted keycap has essentially no sliding friction, which means very little difference in force required between hitting it obliquely or perpendicularly.
Isn't buying a premade MCU board for a "keyboard from scratch" cheating a little? I'd go with a deadbugged 8749 in a DIP-40 package, the classic MCU for a keyboard controller. :-)
Re: My First Keyboard Build
#18if anyone doing a hand-wired build has a better/more efficient method of making the cables for the columns, please let me know Use self-fluxing enameled wire. It's insulated with an enamel that melts/converts into flux at soldering temperatures, so all you need to do is wrap a turn around the post of each switch contact for a column, then add solder to complete the connection. Some are sold in a convenient pencil-sha…
Oh wow thanks for the wire tip! That will definitely make life easier :)
As I say to everyone questioning whether to do a keyboard build (or any DIY project) - go for it! Let me know how you go :)
edit: Didn't see your comments about the cheating bit. You are right, it probably was cheating a touch - it didn't quite occur to me until you said it. I'll see how I go with my next build and work out how to cheat a bit less, haha!
Re: My First Keyboard Build
#19Now make a dictaphone :P
For real though, here's another guy who makes keyboards:
http://mykeyboard.co.uk/microswitch/
They're a bit weirder and with very light switches.
Re: My First Keyboard Build
#20Current keyboard designs bug me, to put it mildly. Put a mux on each group of switches, have the microcontroller rapidly scan the muxes to determine which switches are down. And now all of a sudden you have a keyboard that you can actually press down as many keys as you need and it still works. Except it won't. Because USB keyboards don't support arbitrary numbers of keys being pressed at once.
"Because USB keyboards don't support arbitrary numbers of keys being pressed at once." There is actually nothing in the USB or HID specifications preventing USB keyboards from supporting n-key rollover (when using the report protocol -- keyboards using the boot protocol are limited to a 6-key rollover). The reason most don't is simply to reduce cost and complexity. A sufficiently motivated person could build a USB-co…
Apparently there are all kinds of interesting bugs out there in the wild that you run into if you actually build a USB keyboard with full n-key rollover - enough that most manufacturers just emulate two keyboards and call it a day.