My custom unique looking "Rapture" keyboard build log

[dj027x]

So, I'm a fan of mechanical boards. (even though I currently use a microsoft sidewinder despite owning an apple extended2, dell at101w(my favorite) and an nmb) Im also a fan of modularity, and embarking on home projects. I just finished a replica of Milton's red stapler from 'Office Space', so it's time for a new project; A very unusual, unique, customizeable mechanical keyboard. Heres some the concept design i threw together with gimp:

I rejected tradition.
Instead, I chose something different.
I chose the impossible...
I chose Rapture;

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The keyboard where the artist would not be bound by single colour leds,

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Where the scientist would not be bound by petty non-programmable keys.

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And with the sweat of your brow, it can become your keyboard too.

Yes, it looks unusual, with the grid layout, 1x1 windowed keys, and rather tiny (smaller than the poker 2) but let me explain why I chose these features (and feel free to leave constructive or destructive criticism, your choice  (seriously, I'd like to know how ugly you think it looks)):
-Teensy 3.1 microcontroller, seemed like the obvious choice for documentation, cost, ease of use, and functionality. I may switch to a de0-nano fpga if I need more jiggawatts later on.
-Programmable keys, made possible by the uC, so you can switch modes to get arrow keys, symbols, alternate layouts, macros etc.
-NKRO... why not? Its easier to make and simpler to understand than non-nkro as far as I'm concerned
-Its a keyboard, not a typewriter; why should I use staggered keys when ortholinear is more ergonomic?(this one's subjective)
-cherry mx clears cuz I like em. (I was considering whites just cuz they're more rare lol, and decided against matias cuz caps don't exist, though I do love the feel of alps)
-Blank keycaps, because A: screw qwerty and B: lends itself to fully programmable keys, and looks pretty fly.
-Small, for portability obviously
-Windowed keys, because full transparrents just look kinda cheap to me, and it definitely gives it a very unique look.
-Bioshock references, because I'm a geek, the quote seems relevant to choosing how you want your keyboard and Andrew Ryan is my hero, behind Nikola Tesla and Elon Musk. (Ryan is the fictional Elon! Or is Elon Comstock?  anyway...)
-INDIVIDUAL PER-KEY PROGRAMMABLE RGB BACKLIGHTING!!! Yep, the keys will be able to be programmed to respond to your touch, or give you beautiful colourful feedback. (heck, I intend to use them to display the memory contents of the microcontroller so you can literally use this board to program itself!!(yea, in machine code, but what do you expect?; I'm a comp eng  ))
There are definitely some hurdles to overcome, but that's what makes it fun =)
Glass ceiling: 200$

So what have I done so far? Nothing  Because I'm waiting on my parts to arrive 
The board has 48 keys (subject to change) but I ordered 50 clears, and 52 keycaps incase of defects. So I'm currently waiting on those to arrive so I can determine whether I will be able to pull off RGB backlights. MX switches only physically support 3mm leds, but afaik, 3mm rgb leds don't exist. So if I can modify them to accept 5mm rgbs, or square leds, the projects is a go. I will then order probably 100 leds, and begin the pcb design. I intend to have a multiplexed matrix design, with the teensy reading 6 keys per scan, and 8 scans per cycle; 6*8=48; nice and simple. I have the means to print, etch, drill, and solder the board at home, so that's what I will be doing. The led circuit will be a tad more complicated. Regarding the leds, if I go analogue, Ill need a resistor ladder, hefty current source, and 3 capacitors per led (probably not possible for my target dimensions) So it looks like I'm going the digital route: I would like to use the teensy's multiple built in pwm pins to drive the leds without sacrificing any clock cycles from key detection, but I'd still need 3 caps per led, and there are other logistics preventing that from working. (plus caps are a common point of failure in electronics). Afaik, my best option is getting some TTL ICs, and yes, I'll need 48*3=144 elements. (the FPGA route is looking more and more attractive). I should be able to get away with 144 extremely simple D-Latches in the form of 36 16-pin DIP ICs and still keep it tiny. (Unless I'm crafty with my design, this could end up requiring a multi-layer PCB solution). Phew, once that's all said and done... add joysticks? haha I toyed with that idea, but I'm content with my already complicated design. Maybe in the future. As for the lettering on the keycaps... Laser? (Don't yell at me, but they're also ABS :/) The final step (for assembly at least) would be buying or fabbing a slick case to hold it all together; Should be pretty simple. Once assembled just plug-and-play, err... program... the entire controller from scratch. (Hope I havn't wired anything wrong at this point!) Yup It's ambitious; I know. But I have to go through with it now that Iv'e put money into switches and caps. In for a penny, in for a pound! I'll make any practical or necessary adjustments along the way ("Eventually we adapted it from invisibility to just not being seen" lol) and I'll of course leave room for future improvement, and document every step for you! If there is enough interest I will design a (relatively) easy to use software interface; free, as in 'beer' AND 'freedom'!. BTW, keycaps are from SP, but it looks like they no-longer sell the packs that I bought.

[howthegodschill]

Damn, this is tight. I'm excited to see how this comes out in the end.

[CPTBadAss]

Please take pictures of the PCB etching process

[dj027x]

Please take pictures of the PCB etching process

Will do! I'm going to use the toner transfer method if you care to know. Possibly 2 separate boards with wire interconnects, depending on what size board I can get a hold of

[Findecanor]

Milton's red stapler huh ... 646 or 747?

There are people who have used RGB LEDs with Cherry MX, bent inwards under the keycap.
The ones in the Corsair keyboards have transparent casings with SMD:d LEDs underneath and they have been exclusive to Corsair during 2014 and I think they should become available soon... You could ask 7bit about them: he is often selling switches and has planned to sell the clear-cased ones. I don't think Cherry makes clear-cased MX Clear though...

As to driving the LEDs, there are a bunch of people everywhere who have made LED matrices run by an Arduino and a bunch of shift registers, but there are dedicated LED matrix controller chips out there that can drive matrices with PWM for 256 shades of grey scale.
The firmware for the Red Scarf II is made for an AVR µC (as in Arduino) and a shift register.

As a starting point for using the Teensy 3.0, you could use HaaTa's Kiibohd firmware. It supports it, the AVR in Teensy 2.0 and a few others microcontrollers.

[DrHubblePhD]

We need to talk, I am a HUGE bioshock fan!

[vvp]

I'm going to use the toner transfer method if you care to know.

We used it for Katy. It works without a problem with min track width 0.3mm and min clearance 0.25mm, via Φ1mm and via drill Φ0.5mm. Somewhat smaller features should be possible too. I think it is easier than trying to build circuits with jumper wires on a breadboard. No breadboards for me except for the very simple stuff.
Here is our first attempt at it: http://deskthority.net/workshop-f7/katy-keyboard-or-k80cs-key80-contoured-split-t8524.html#p191612
If you did not do it yet I have two good rules:

• If the toner print on the PCB does not look good do not even try to etch it. Clean it with acetone and transfer toner on the PCB again. It does not take long.
• Do not leave it in the etching bath for too long. Regularly check whether it is not done yet.

A positive photoresist is already bought if there would be need for finer stuff

[dorkvader]

Milton's red stapler huh ... 646 or 747?

It was their 747 in "rio red" although swingline did not make it at the time. The prop used in the film was the normal one that had been painted.

[dj027x]

Milton's red stapler huh ... 646 or 747?

646 of course!

It didn't turn out perfect; There's slight orange peel, and drip lines that the camera angle hides, and I had to cut out the damn logo by hand with an exacto knife, but it was literally the first time I ever did a paint-involved project, so I'm happy with the result considering my low skill level. It was very tedious and time consuming, but a welcomed experience.

There are people who have used RGB LEDs with Cherry MX, bent inwards under the keycap.
The ones in the Corsair keyboards have transparent casings with SMD:d LEDs underneath and they have been exclusive to Corsair during 2014 and I think they should become available soon... You could ask 7bit about them: he is often selling switches and has planned to sell the clear-cased ones. I don't think Cherry makes clear-cased MX Clear though...

My switches just arrived (im actually about to post an update here) and it looks like 5mm leds might just fit; I'll have to wait for the caps to get here to be sure though. I was definitely interested in clear body switches, but the only ones i found were matias, and I had no luck at all finding matias/alps compatible keycaps.

As to driving the LEDs, there are a bunch of people everywhere who have made LED matrices run by an Arduino and a bunch of shift registers, but there are dedicated LED matrix controller chips out there that can drive matrices with PWM for 256 shades of grey scale.
The firmware for the Red Scarf II is made for an AVR µC (as in Arduino) and a shift register.

As a starting point for using the Teensy 3.0, you could use HaaTa's Kiibohd firmware. It supports it, the AVR in Teensy 2.0 and a few others microcontrollers.

The matrix controller chip seems like a good idea; I'll look into that tonight.
The one part I'm not particularly looking forward to is programming the usb protocol for the teensy(if it doesn't have a pre-made one. I haven't looked into it much yet), so I'd totally be into using some already made firmwares as a baseboard. Thanks for the info!
BTW, what lube would you recommend for the switches? I see in your signature you've got some lubed clears

[dj027x]

Milton's red stapler huh ... 646 or 747?

It was their 747 in "rio red" although swingline did not make it at the time. The prop used in the film was the normal one that had been painted.

It's unfortunate that the production stapler looks nothing like the movie prop lol, not sure what swingline was thinking there. Then again, if it did look like the prop, I would have missed out on the fun of making it myself.

[dj027x]

We need to talk, I am a HUGE bioshock fan!

Glad to hear it! My love for it comes from Bioshock more-so than Bioshock 2 or Infinite (Although they were both still good, and the end of infinite figuratively blew my mind haha)
Have you by any chance played System Shock 1 &/| 2? I believe it's where Bioshock got its inspiration from, so I got a few minutes in, but college work restricted me from sticking with it :/
(Though I may start back up again soon!) It's a pretty cool game if your into that old pixely stuff.

[DrHubblePhD]

We need to talk, I am a HUGE bioshock fan!

Glad to hear it! My love for it comes from Bioshock more-so than Bioshock 2 or Infinite (Although they were both still good, and the end of infinite figuratively blew my mind haha)
Have you by any chance played System Shock 1 &/| 2? I believe it's where Bioshock got its inspiration from, so I got a few minutes in, but college work restricted me from sticking with it :/
(Though I may start back up again soon!) It's a pretty cool game if your into that old pixely stuff.

I dont blame you for not liking bioshock 2, I usually tell people to skip it, but infinite was outstanding IMO. Especially if you play through burial at see which really closes up the series perfectly.

I actually haven't played system shock yet, I usually am not into that style, you know the huge inventory RPG like games. Although im sure its different from what I am imagining.

[dj027x]

We used it for Katy. It works without a problem with min track width 0.3mm and min clearance 0.25mm, via Φ1mm and via drill Φ0.5mm. Somewhat smaller features should be possible too. I think it is easier than trying to build circuits with jumper wires on a breadboard. No breadboards for me except for the very simple stuff.
Here is our first attempt at it: http://deskthority.net/workshop-f7/katy-keyboard-or-k80cs-key80-contoured-split-t8524.html#p191612
If you did not do it yet I have two good rules:

• If the toner print on the PCB does not look good do not even try to etch it. Clean it with acetone and transfer toner on the PCB again. It does not take long.
• Do not leave it in the etching bath for too long. Regularly check whether it is not done yet.

A positive photoresist is already bought if there would be need for finer stuff

Katy looks stellar, man! I hadn't considered a floating matrix like that. I am now though Yep I've used this method before, but I was using .762mm traces. I couldn't imagine going much smaller haha. I bought a micro drill set for my dremel tool for this type of thing, and its _just_ small enough for a .7mm id via. I use isopropyl alcohol to dissolve the paper after the hot water bath, then gently rub some etchant into it, and give it an acetone rubbing to get the toner off. I _might_ consider applying a solder mask this time, though I don't suspect I'll have any reason to do so. I bought a brother HL-L236ODW laser printer specifically for pcb making, and it has the option for extra heavy printing, so the print is usually pretty good, although the resolution could be better. .7mm traces is about the limit of quality for it. I believe I recall the photoresist method being slightly more expensive, which is why I went toner transfer, "if I'm correctly mistaken".

[dj027x]

I dont blame you for not liking bioshock 2, I usually tell people to skip it, but infinite was outstanding IMO. Especially if you play through burial at see which really closes up the series perfectly.

I actually haven't played system shock yet, I usually am not into that style, you know the huge inventory RPG like games. Although im sure its different from what I am imagining.

ARGH! I really need to play burial at sea. I got about 2 minutes into it before I got busy with other work. (I really should play all my steam games instead of only buying them. ive played roughly 20 out of 170 haha)
"Sale you say? Yea, I might play that someday... And I sure don't want to lose money on this... Better buy it now"

[dj027x]

Seem to be having some trouble posting my update. When I submit it, it takes me to a "create a new topic" page. hmmm. It has 32MB worth of pics. Would that do it?

[dj027x]

SORRY about this update being broken into several posts. It didn't let me upload more than 3 pics per post :/
Update 0: That's right, I zero index things.
The switches have arrived!

My pretties:

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I'm a tad disappointed with the packaging; they came in this plastic bag, wrapped in brown paper. Some of the pins were bent upon arrival. I guess it keeps cost down, and for the most part, one gas to simply bend the leads back into place and all is well. Oh yea, my updates might have lots of pictures...

Muahahaha

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So far, my 'obtained parts list' includes the teensy and switches. Still waiting on the caps to get here.
Here an hd pic of the teensy, cuz why not? (A big thanks to the geekhack admins for hosting this fantastic site btw. It is very much appreciated!)

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[dj027x]

So the switches are actually a lot smaller than I imagined they would be. I guess the camera adds 5 grams?

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Tiny buggers

[dj027x]

So it looks like a pretty tiny hole for the led there. There is a cylindrical slot to house the led body, and a rectangular cavity that leads downward to 2 tiny holes where the led pins com out the bottom.
I tried to get some decent shots of the front and back here. Something interesting to note: There are 4 holes on the back side, but the outer 2 are walled off from the inner 2, and I am stumped as to what the outer 2's purpose might be. I suspect cherry designed this body with the hopes that 3mm rgb leds might be developed soon, but why wall off the holes? Structure? Modding restrictions? In any case, that's only a guess as to their purpose.

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[dj027x]

Here is the hole compared to a 5mm led

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As-is, a 5mm led doesn't quite fit in there

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[dj027x]

Popped it open to find some pretty mechanics, and I could actually see the lube between the stem and metal; nice quality.
WARNING: nudes

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With the top off, it appears that the led can actually fit in there without affecting the operation of the switch. It will require some of the body be cut away though.

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[dj027x]

I would have to cut off the south (when looking down at it) part of the top half of the body. This would allow the led to fit without opening up the wall that houses the mechanics, but it would remove a clip that is meant to hold the body to a pcb. I don't think this will cause an issue though.

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Just for kicks, I threw a 3mm led I had lying around in there. Even if a 3mm has a flange, it doesn't sit quite right.

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So, I'm just waiting for dem caps to arrive, and I can determine if I'll be able to get the 5mm leds in there without keycap collision. I love the way they feel too. The stems have a bit of wobble, but nothing I didn't expect. Another less picture-oriented update will be coming once my caps get here.
Also, I should actually be able to mill the case out of the acrylic found in flatscreen monitors. Ill probably use some acetone and dye to paint it. Probably guna have to buy the nuts and bolts to hold it all together though.
Sorry about this update being split into several posts. It wouldn't let me upload more than 3 pics in a post :/

[Findecanor]

646 of course!

Nice and glossy.   I made mine years ago from a 646 and decals I had bought from a guy on the Replica Prop Forum.

BTW, what lube would you recommend for the switches? I see in your signature you've got some lubed clears

I used RO-59KT. But after two years I am not so sure that the keys are so smooth as they once were.

With the top off, it appears that the led can actually fit in there without affecting the operation of the switch. It will require some of the body be cut away though.

You may also be able to cut away some from the LED without affecting how it works, as long as you don't cut down to the metal or silicon. Tedious work though.. 

BTW. Bi-colour LEDs exist in 3 mm. They are either three-pin (one common lead) or two-pin in different directions. Ducky has made a few keyboards with bi-colour LEDs, but I dunno which variant they use.

[vvp]

I've used this method before, but I was using .762mm traces. I couldn't imagine going much smaller haha. I bought a micro drill set for my dremel tool for this type of thing, and its _just_ small enough for a .7mm id via. I use isopropyl alcohol to dissolve the paper after the hot water bath, then gently rub some etchant into it, and give it an acetone rubbing to get the toner off. I _might_ consider applying a solder mask this time, though I don't suspect I'll have any reason to do so. I bought a brother HL-L236ODW laser printer specifically for pcb making, and it has the option for extra heavy printing, so the print is usually pretty good, although the resolution could be better. .7mm traces is about the limit of quality for it. I believe I recall the photoresist method being slightly more expensive, which is why I went toner transfer, "if I'm correctly mistaken".

You definitely can go down to min track width 0.3mm and min clearance 0.25mm, via Φ1mm and via drill Φ0.5mm. This is what we use with a 1200 dpi laser printer.  But I believe 600 dpi would be enough too. I believe it may be possible to go down to 0.2mm traces and 0.15 clearance but I did not try it.

As for as the drills. You can buy thin drills which have a thick stem. Here are some examples: http://www.proxxon.com/en/micromot/tools_drills.php?list
Although, it is good to have a drill press so that you do not break the drills.

The whole magic is: If the toner transferred nicely to the PCB. I.e. it sticks and did not deform much then it will etch nicely too (provided you will not leave it in the etching bath for too long).

We tried to print on an expensive glossy photo paper and transfer from that to PCB. That did not work well. A thin glossy paper from an old electronic parts catalog works very well. After we transferred toner from paper to PCB we put it to hot water bath (about 40°C), leave it there for a few minutes and then used an old tooth brush to rub the paper from the PCB. It is also important not to contaminate the paper or the PCB with oils before transferring (i.e. do not touch the surfaces).

I believe solder resist is needed only for really small feature sizes. No need for the stuff toner transfer method can produce.

Yes, photo resist is a more expensive and, in the case you are making the photo resist coating yourself, also more work. Although in that case it is not that much expensive on average.

Photo resist method can do smaller features. It is more consistent. Not my experience yet but that is what the tutorials claim :-)

[dj027x]

We tried to print on an expensive glossy photo paper and transfer from that to PCB. That did not work well. A thin glossy paper from an old electronic parts catalog works very well.

Did you have to find a blank page? I would expect whatever was printed on the page to be transferred as well. I was going to try some sticker backing paper next time, but perhaps I'll try some catalog paper.

[dj027x]

Keycaps just arrived! I'll do another update once I get home, and I'm going to spend my week in florida designing the pcb. I'll throw my design on here before finalizing anything so you guys can critique it.

[dorkvader]

Milton's red stapler huh ... 646 or 747?

It was their 747 in "rio red" although swingline did not make it at the time. The prop used in the film was the normal one that had been painted.

It's unfortunate that the production stapler looks nothing like the movie prop lol, not sure what swingline was thinking there. Then again, if it did look like the prop, I would have missed out on the fun of making it myself.

The 646 is their plastic version, a "lower end" of the 747. It makes sense to only do a "limited edition" (or special edition / colour whatever) on the higher end product.

I was planning on painting my vintage swingline model 31 (ca 1932) red and see if anyone gets it. I used to have a boston stapler but they tend to jam up too much.

Please let us know about the results of toner transfer. I read all I can about this before I try it myself to maximize my chances of success.

[dj027x]

I read all I can about this before I try it myself to maximize my chances of success.

That's always a good approach. I like to do a lot of hands on experimenting as well. Small scale testing is good (practice makes 'good enough').  The first time I did it was it an EE class where I decided not to send a board design to be fabbed like everyone else in the class, but to make my own. I had one shot to get it right or fail the class haha. My board ended up being like 8x smaller than everyone elses, had a ground plane, and pads on the sides to connect alligator clips. I did really well for my first time ( story of my life ) In fact, heres a pic:

[dj027x]

Update 1 (In several parts, I'm afraid:
TLDR: good news is I'm awesome and got everything to fit! Bad news is I have to mod every switch case and led to make it work.

So the caps arrived! I had to buy in packages of four. They all look very well made. No defects spotted yet. They're abs, but they've got a nice rough texture. Plus I have 8 extras if any start to smooth out.

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Here's what the layout is going to be like:

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I even with the top half of the case off, no way in hell 5mm leds are fitting under the caps. The cap sits at normal height, but you can't fully press the key down.

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[FrostyToast]

May I ask why you are using 5mm LEDs?
Those things are obviously way too oversized.
The largest you can go for LEDs would be 3mm.

[dj027x]

I ground down the led body, which actually made the led a bit diffuse due to the now-rough outside, which in the case of rgbs is a good thing.
I then took a chunk out of the top of the switch body, and was able to leave the clip on the bottom half of the body intact.

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I could get the led a bit smaller, but I know the RGB leds are going to be a tad bigger anyway, so I left it as you see in the next pic. Slid into the modified case, it looks like it just might fit under the cap.

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[dj027x]

May I ask why you are using 5mm LEDs?
Those things are obviously way too oversized.
The largest you can go for LEDs would be 3mm.

Unfortunately, RGB leds don't come in 3mm. 5mm are the smallest.
But thats why I'm grinding them down to nubs!

[vvp]

Did you have to find a blank page? I would expect whatever was printed on the page to be transferred as well. I was going to try some sticker backing paper next time, but perhaps I'll try some catalog paper.

No I do not care what is printed on the page. If you can use a blank page then it is a bit better since it is easier to assess whether it printed well. I'm only making sure that there are no wrinkles on the page (i.e. checking that the surface is smooth).

The old print on the page will not transfer to the PCB. Realize that toner is about half plastics and the rest is black color (possibly fine sooth). The plastics is what you are using as mask for etching. The original colors do not contain it. Mkawa (or somebody else) can probably even tell you what is exactly in black toner and what is in standard print-press inks.

[FrostyToast]

May I ask why you are using 5mm LEDs?
Those things are obviously way too oversized.
The largest you can go for LEDs would be 3mm.

Unfortunately, RGB leds don't come in 3mm. 5mm are the smallest.

I swear that Kaliet used some RGB LEDs on some of his boards...
Go chat him up and see what he used.

[dj027x]

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*click* (yea they're non-clicky, but I'm trying to be dramatic here)

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[dj027x]

I swear that Kaliet used some RGB LEDs on some of his boards...

I took a look at some of his pics. It looks like he's using multiple color leds per board, but each switch is still single color :/
Though one of his boards did use RGB LEDs on the bottom of the board, as a backlight
I shot him a message to double check.
I'll wait on his response before putting money into hundreds of leds haha.

[dj027x]

So now that I know it's possible, time to order the RGBs!
Regarding another aspect of the project, I pulled the plexiglass(or whatever material it is) out of a junked monitor. Probably going to double it up, mill it and paint it to use it as a the case

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Ah yes; almost forgot to check that the led works after all that grinding. (never drive a led you intend to keep alive without current limitation. I only lit this long enough to snap a quick pic)

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See you next update. (Its probably going to regard the pcb design)

[dj027x]

As for as the drills. You can buy thin drills which have a thick stem. Here are some examples: http://www.proxxon.com/en/micromot/tools_drills.php?list
Although, it is good to have a drill press so that you do not break the drills.

That's exactly what I need haha. I've been using bits that are like .7 mm diameter from end to end, and they tend to wobble as a result of not sitting centered in the chuck.
I'll definitely pick up a set; not from there though, its a tad pricey with the shipping.

[FrostyToast]

Well Sprit does have this video clearly showcasing 2x3x4 RGB LEDs.
No idea where he got them from.

https://www.youtube.com/watch?v=o2oAjCjCaUE

[dj027x]

Ah my apologies; I should have clarified, 3mm rgb leds do exist, but I'm looking for separate channels for the r, g, and b components. You can see in the vid those leds only have 2 leads, and they actually transition through the colors automagically. Afaik, there's no way to set them to a specific colour unfortunately The reason 3mm controllable leds don't exist is because they just can't fit 4 pins (one for each channel and one common annode or cathode) within 3mm. Or at least they wouldn't make a profit doing it. I could use smd leds suspended by wires I suppose, but I think that would be more of a pain than grinding down 5mm leds

[dj027x]

update 1_1: I just had 2 ideas, I feel like an idiot for not thinking of the first earlier:
Firstly, Why the hell am I messing around with the typical semi-capsule shaped 5mm leds when I can just use square leds?
I was actually looking around for other led options when I saw a picture of them and I wondered to myself why I haven't considered using them yet, and now I probably will.
I was able to find some 2x5x5 mm ones, which will DEFINITELY fit in the modded cases (so long as 1 of the dimensions is 3mm or less and another is 5mm or less). I may be able to find even smaller ones with a bit of searching.
(Thanks to FrostyToast for suggesting other options; I probably wouldn't have found this otherwise)
2nd idea: The window in the keycaps is not diffused; it's quite transparent, so I'm worried that the light from the led either wont propagate evenly, or it will be blinding to look at the keys, because you'd just be looking straight into the leds. Well if that is the case, I should actually be able to rotate the switches and caps, so the led and window are on the north side of the key. The transparent bit on the top of the keycap (which is actually a little diffused due to the rough texture on the top of the keycap) would still light up, and be visible to the typist, and the window on the side of the keycap would allow the led to cast a glow onto the keys behind (north of) it.
Might cause a cool effect; I'll toy with the idea later on.

[dj027x]

Just bought 100 2x5x5 rgb leds. for 22$
Unfortunately they will take 5 to 27 days to arrive lol.
In the mean time, I'll be working on the pcb design
Honestly, I'm not sure why nobody has done this before (that I know of).
Perhaps I'll run into some insurmountable roadblock here, but till then, onward!

[neverused]

Honestly, I'm not sure why nobody has done this before (that I know of).

Do you mean rgb backlight a matrix keyboard?

[dj027x]

Do you mean rgb backlight a matrix keyboard?

Even just per-key RGB backlighting. Isn't corsair's K70 and some razer thing the only ones ever to do it? And only just last year right?
This is definitely the first diy project I know of to do it

[dj027x]

Feel free to point out any error in my math.
I'm trying to determine the frequency of the signal the teensy will need to send to the leds to control them nicely.
Lets consider the board to just be a 12x4 screen.
Let's aim for 30Hz refresh rate, and 9-bit colour (3 bits per channel), for now.

Assuming the setup will consist of the teensy driving multiplexed d-latches, which in-turn drive one component of one led, driving the display would require 144 d-latches and 2 signals, both at:
(48 leds times 3 channels per led times 30Hz refresh rate times 2^3bit per channel=9 levels of intensity per channel = 48*3*30*9=) 38.88kHz

If I can miraculously find compact multiplexed 3-bit PWM ICs (I have my doubts that they even exist but one 18 pin IC could house 8 (might get hot)), I would be able to use 144 PWM drivers with 4 signals at:
(48 leds times 3 channels per led times 1 PWM driver per channel times 30Hz refresh rate = 40*3*30=) 3.7kHz

So there is a trade-off between complexity and speed (as there often is).

Now, the teensy 3.1 does have a 72MHz clock, but there's calculations it handles every cycle, so without actually testing it, there's no telling what freq I'll be able to drive leds at, although its safe to say it will be well below 72MHz. I'll investigate this further over the next few days, because the solution I determine here will affect my PCB design.

[dj027x]

Well I seem to have overlooked the fact that each led will also require 3 resistors. Because the leds are common anode, I will be able to use those fancy resistor ic's that have a common ground. No big deal, but the design will just require that much more realestate. This is definitely going to be a double sided pcb or multi-layered solution.

[dj027x]

School has started up again, so progress might become intermittent, however, the rgb leds have arrived!

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The pictures may be of poor quality; I broke my phone's digitizer over break so I'm using an old phone to take the pictures.
Conveniently, the planck keyboard parts would work nicely for this project, however I don't like the way the keys protrude from the top of the planck.
I would like the bottom of my keycaps flush with the top of the case. I might be able to use the top plate for the planck though, to hold the switches and keep pressure off of the pcb.
Next step is modding each switch case to accept the rgb leds.
I'll update y'all when that's complete

[Evo_Spec]

School has started up again, so progress might become intermittent, however, the rgb leds have arrived!

More

(Attachment Link)
(Attachment Link)

The pictures may be of poor quality; I broke my phone's digitizer over break so I'm using an old phone to take the pictures.
Conveniently, the planck keyboard parts would work nicely for this project, however I don't like the way the keys protrude from the top of the planck.
I would like the bottom of my keycaps flush with the top of the case. I might be able to use the top plate for the planck though, to hold the switches and keep pressure off of the pcb.
Next step is modding each switch case to accept the rgb leds.
I'll update y'all when that's complete

Wow those are huge, i'm curious to see how you're going to fit it.

[dj027x]

Wow those are huge, i'm curious to see how you're going to fit it.

I've already tested that they fit. I'll throw up a picture when I get the first one assembled. Right now it's just a matter of drilling extra holes for the led leads.
I'm also looking into using kicad, so I should have a schematic relatively soon.

[dj027x]

leds seem to function nicely, and are decently bright even at low amps. They do however blow instantaniously when 9V is put across them, other like the typical 5mm red leds. I'm looking into various led matrix drivers at the moment.

[CPTBadAss]

Do those LEDs cause any interference with the switch actuation? And ugh, I need to learn more about this PCB etching process you and vvp keep talking about.