New to the forum, want to build my own keyboard add on

[overture1928]

Hi  guys,

I am new to the forum. I have a little summer project. I want to build my own custom keyboard using mx switches (Please see picture). Because I am not 100% on the layout I want to be able to play around a bit and be flexible. I was thinking of soldering small square PCBs to the bottom the switches with wire leads that would make their way to the micro processor/controller. I think this is all I need:

Cherry MX Keys (Brown, Blue, or Black)
Mounting plate for the keys
PCB
Wire leads
Some sort of micro processor.

I don't need any sort of case or enclosure... yet.

Just wondering if anyone could give me some suggestions sourcing parts, processor options, or any suggestions or advice especially when it comes to programming the device.

[Djuzuh]

What's the point of the little PCB thingies at the bottom of the switch?

Check out those https://lh5.googleusercontent.com/-ovZJihnxd2U/UADubh5WZRI/AAAAAAAACwA/aUiNfUU-Ol8/s600/HBFS30_linkline.gif

[fartq]

quick release and crimp connectors are more fiddly than one would think. the pro way of doing this is lowpoly's point-to-point method. another way is to just get a large piece of proto-board and wire the eyelets together

[overture1928]

What's the point of the little PCB thingies at the bottom of the switch?

Check out those https://lh5.googleusercontent.com/-ovZJihnxd2U/UADubh5WZRI/AAAAAAAACwA/aUiNfUU-Ol8/s600/HBFS30_linkline.gif

Interesting.

I don't know exactly how MX switches work inside but would those wires be hooked up to the leads at all times? Is there some other contacts inside the switch that knows to send a signal when the switch is pressed?

[overture1928]

quick release and crimp connectors are more fiddly than one would think. the pro way of doing this is lowpoly's point-to-point method. another way is to just get a large piece of proto-board and wire the eyelets together

Can you give me a link to lowpoly's method?

[alaricljs]

Lowpoly's method is just plating up the keys and doing point to point wiring directly to the switch leads.

[braaaiiins]

Interesting.

I don't know exactly how MX switches work inside but would those wires be hooked up to the leads at all times? Is there some other contacts inside the switch that knows to send a signal when the switch is pressed?

The leads must always be attached. Like any switch, these mx switches physically connect the two terminals. MX switches are NO (normally open) which means when they are pressed down they close the switch and presto, a key is triggered.

edit:

And welcome to the forum. Wish you the best of luck on your project. Please post pictures!

[theultrazord]

For the controller people have recommended using a teensy as it uses the atmegau32 controller which will be recognized by your computer as a human interface device.

http://www.pjrc.com/teensy/td_keyboard.html
http://www.pjrc.com/store/teensy.html
http://www.pjrc.com/teensy/usb_keyboard.html

Also look up how to set up a keyboard matrix. If you want to break down something that exists and use that, http://deskthority.net/workshop-f7/reversing-a-keyboard-matrix-t7.html is a good tutorial on figuring out what is assigned to what so you can just take the chip and use it in your new keyboard.

Also if you are going to plate mount but use wire leads its a good idea to just pick one out of a cheaper keyboard that you have lying around (if its larger than what you want saw off the Fkey and everything right of the main letter pad so its a 60% board).

Edit: If you change your mind and want to make your keyboard out of bananas or cereal you could use http://www.kickstarter.com/projects/joylabs/makey-makey-an-invention-kit-for-everyone and have most of the work done for you.

[overture1928]

Interesting.

I don't know exactly how MX switches work inside but would those wires be hooked up to the leads at all times? Is there some other contacts inside the switch that knows to send a signal when the switch is pressed?

The leads must always be attached. Like any switch, these mx switches physically connect the two terminals. MX switches are NO (normally open) which means when they are pressed down they close the switch and presto, a key is triggered.

edit:

And welcome to the forum. Wish you the best of luck on your project. Please post pictures!

Thanks man! Totally answered my question

[overture1928]

What's the point of the little PCB thingies at the bottom of the switch?

Check out those https://lh5.googleusercontent.com/-ovZJihnxd2U/UADubh5WZRI/AAAAAAAACwA/aUiNfUU-Ol8/s600/HBFS30_linkline.gif

Where can I buy these leads?

[overture1928]

So far the cheapest place I have found to buy keys is here http://components.arrow.com/part/detail/2079176S3258487N7219 for 0.54$ US a key. That seems like a good price. Is there anywhere cheaper to purchase them? What if I wanted to purchase say 1000 keys or so?

[alaricljs]

Arrow can quote you a quantity price, Mouser has public price tiers (but looks like higher pricing in general compared to Arrow).

[braaaiiins]

Holy moly, 1000 keys?? What do you need that many for? Trying to manufacture more boards for your fellow hackers? =P

 There are plenty of cheap old boards that you can salvage keys from. There's a full (albeit dead) mx black board in the classifieds right now for $20 - Less than $0.20 a switch. Also, I would like to know where those leads can be found too.

[hazeluff]

PrinsValium had a thread here before, but the links are all broken. It had stuff on building your own PCBs instead of using a Veroboard with lots of wires going everywhere.

If you've got room, a teensy is a good way to go. That way you can reuse pjrc's firmware (or at least the usb_keyboard code). Also programming seems to be pretty straight forward, and you can pretty much just rewrite the Phantom's firmware to suite what you need. When you're at the stage of needing help, just ask.

As for sourcing parts, you'll have to look around. But i've gotten electrical components from RS at a good price with fast shipping.

As for switches...= / Either you buy a ton (like 1000+) or you get them a bit more expensive from WASDkeyboards/Ebay. Or you could yeah take apart a old board for switches.

[Icarium]

There is actually a thread over on DT where somebody who wants to make his own PCB as well is talking to PrinsValium (who calls himself bpiphany now). http://deskthority.net/workshop-f7/need-help-with-cherry-pcb-t3538.html

[overture1928]

I don't really need/want to make my own PCB. At least not a PCB where all of the keys are mounted onto. I want wires going from each individual key to the controller.

[bpiphany]

You are going to  want to mount the keys onto/into something. Do you have any plans for that? Usually either a PCB getting all the traces as well straight away, or a mounting plate and fly wiring the switches on the back..

Edit: Ok saw that part on having a mounting plate. That is certainly a doable way =)

[overture1928]

You are going to  want to mount the keys onto/into something. Do you have any plans for that? Usually either a PCB getting all the traces as well straight away, or a mounting plate and fly wiring the switches on the back..

Edit: Ok saw that part on having a mounting plate. That is certainly a doable way =)

Yes I have plans for that. Ill show you when it is done.

[overture1928]

Again let me apologize for my newbness but I have a few more questions. Right now I am using a Leopold Tenkeyless and upon close inspection notice when looking at the keyboard from the side view that the key tops have different angles. I assume it is a combination of the PCB being mounted to the case on an angle and the keytops of each row being angled to some %. Is there any standard(s) in the keyboard industry? Also WASD labels rows R1, R2 etc and cherry labels their keycaps A B C D E F is there a standard naming of rows

[alaricljs]

Standard naming of rows: 
R1-R4 WASDkeyboards from the bottom row up: 1/1/2/3/4/4
R1-R4 Signature plastics from the bottom row up: 4/4/3/2/1/1

Fun eh?


As to the angle/curve of the caps, standard caps for Cherry MX switches are of varying heights/top angles across the different rows.  Then the PCB can also be mounted in the case at an angle (like Filco) and then the feet on the case can supplement that angle.


Oooh, SP's DCS profile datasheet

[overture1928]

Thanks!

Would it be terrible if my PCB was mounted completely flat and perhaps all of the key caps were not angled. Grooved yes, but not angled (If possible to get).

[alaricljs]

I don't know what you mean by grooved.  Deck boards are "flat", no variation between row heights.


As far as angle of the board, that's totally up to you and ergonomics.  There are some boards that have adjustable feet to raise the front rather than the back.

[overture1928]

Grooved as in the keys are not flat like a laptop chicklet keys but still have like an indent for your fingers.

[alaricljs]

Ooooh, well, good luck finding that.  SP is definitely the place to look tho.

[overture1928]

Ooooh, well, good luck finding that.  SP is definitely the place to look tho.

will do thanks!

[alaricljs]

And on that note, here's a quick overview of their profiles.  The links are to PDFs, but it's not all there

Sculpted is their term for the row variations.  Touch area is your 'groove', cylindrical being the typical and spherical being more like the cup of a golf tee.

[bpiphany]

Here is the place to look for SP key cap families. Their DSA family might be what you are looking for.

[alaricljs]

Thanks bpiphany, I don't check out SP much.

[overture1928]

2 More questions

Do I need diodes for my switches?

And does anyone know where this guy got this plate? I know it is a phatom plate but what company actually produced the plate and how can I get the dimensions of this cut-out with the notches so that if I ask another company to make my board with those notches they will know how to do it.

feature=plcp

[overture1928]

Here is the place to look for SP key cap families. Their DSA family might be what you are looking for.

Thanks!!

[alaricljs]

The hands in that vid belong to litster, a major part of the Phantom GB.  bpiphany did the board work which I'm pretty sure included the plate design.  biniaris took care of plate production.  I don't recall if the files were released.

[overture1928]

2 More questions

Do I need diodes for my switches?

NVM I found out diodes are only necessary if I want N-key rollover

And does anyone know where this guy got this plate? I know it is a phatom plate but what company actually produced the plate and how can I get the dimensions of this cut-out with the notches so that if I ask another company to make my board with those notches they will know how to do it.

feature=plcp

[bpiphany]

You don't necessarily need diodes, but they stop ghosting (that is the tutorial on the phenomenon) directly in hardware. Without diodes you need to take care of that in software.

I drew the plates for the Phantom. The plate dxf files were released somewhere. May have been here before the move to the new forum. So they may be lost... PM me your mail address and I can send you the KiCAD libraries for you to generate your own.

[overture1928]

You don't necessarily need diodes, but they stop ghosting (that is the tutorial on the phenomenon) directly in hardware. Without diodes you need to take care of that in software.

I drew the plates for the Phantom. The plate dxf files were released somewhere. May have been here before the move to the new forum. So they may be lost... PM me your mail address and I can send you the KiCAD libraries for you to generate your own.

Ok I understand the Matrix and see how diodes fix the problem. My new question is if I get some MX1A-11NN (MX Blues, No Diode) all I have to do is also order some diodes and add them as it shows in the link. If I get some MX1A-11DN (MX Blues, With Diode) is there a diode built into the switch somewhere? It looks like there are 2 extra pins from the cherry data sheet when you order them with the diode but I don't exactly understand how to integrate those pins in the schematic chain, or are they just dummy pins that are necessary for a switch with a diode?

[bpiphany]

The switches with diodes come with a very standard DO-35 package through hole diode built into them. I'm not entirely sure about the polarity now.. But I think there is a diode drawing molded into the plastic on the bottom. So if you find a picture of that =)

I don't know about pricing or availability of switches with diodes compared to the ones without. Diodes are very very cheap though. It's a bit of a hassle to open all the switches up and put diodes into them. I would recommend putting the diodes outside the switches.

[alaricljs]

From the top of the switch the line (cathode) is on the left.

[overture1928]

Need to get my hands on some switches to play around a bit. I need:

3-5 MX Plate mounted (colour doesn't matter so much but prefer Blue, Black or Brown) without diodes or LEDs,
3-5 MX Plate mounted with diodes,
3-5 MX Plate mounted with diodes and LEDs
3-5 1N4148 OR 1N4001 Diodes.

Problem is sourcing all the parts from 1 supplier (who actually has the stuff in stock) so I only have to pay 1 shipping cost. I can't post on the classifieds yet either, anybody have anything laying around?

BTW I am in the Toronto area, Ontario, Canada.

[overture1928]

The switches with diodes come with a very standard DO-35 package through hole diode built into them. I'm not entirely sure about the polarity now.. But I think there is a diode drawing molded into the plastic on the bottom. So if you find a picture of that =)

I don't know about pricing or availability of switches with diodes compared to the ones without. Diodes are very very cheap though. It's a bit of a hassle to open all the switches up and put diodes into them. I would recommend putting the diodes outside the switches.

Yea seems easier to put them on the outside.

[alaricljs]

You can't do diodes and leds in the same switch.

[regack]

2 More questions

Do I need diodes for my switches?

And does anyone know where this guy got this plate? I know it is a phatom plate but what company actually produced the plate and how can I get the dimensions of this cut-out with the notches so that if I ask another company to make my board with those notches they will know how to do it.

feature=plcp

Diodes remove the problem of key ghosting or masking, which you otherwise would have to solve through software somehow.

I have no idea where the phantom plates were made, but I had a plate made by FrontPanelExpress for a little project that I don't have any pictures of... here's what the plate rendered like though.  I'd be happy to send you the file if you want to look at it.  The design program they use is proprietary, but free... not inexpensive... this little thing was something like $60.

[regack]

Need to get my hands on some switches to play around a bit. I need:

3-5 MX Plate mounted (colour doesn't matter so much but prefer Blue, Black or Brown) without diodes or LEDs,
3-5 MX Plate mounted with diodes,
3-5 MX Plate mounted with diodes and LEDs
3-5 1N4148 OR 1N4001 Diodes.

Problem is sourcing all the parts from 1 supplier (who actually has the stuff in stock) so I only have to pay 1 shipping cost. I can't post on the classifieds yet either, anybody have anything laying around?

BTW I am in the Toronto area, Ontario, Canada.

Mouser works well for me, they seem to have everything you want in stock...

To get a good idea of the switches that are offered, at the bottom of this page on Cherry site you can build up part numbers to match what you're looking for...

3-5 MX Plate mounted (colour doesn't matter so much but prefer Blue, Black or Brown) without diodes or LEDs,
   MX1A-E1NN (Panel Mount blues)
   http://ca.mouser.com/Search/Refine.aspx?Keyword=MX1A-E1NN

3-5 MX Plate mounted with diodes
   MX1A-11DN (Panel Mount blacks)
   http://ca.mouser.com/Search/Refine.aspx?Keyword=MX1A-11DN

3-5 MX Plate mounted with diodes and LEDs
   As alaricljs said, they make either LED or Diode, or none, but no switch with both included

3-5 1N4148 OR 1N4001 Diodes
   http://ca.mouser.com/Search/ProductDetail.aspx?qs=HfDODkYFUverVKi/J/e5IA==

[overture1928]

Need to get my hands on some switches to play around a bit. I need:

3-5 MX Plate mounted (colour doesn't matter so much but prefer Blue, Black or Brown) without diodes or LEDs,
3-5 MX Plate mounted with diodes,
3-5 MX Plate mounted with diodes and LEDs
3-5 1N4148 OR 1N4001 Diodes.

Problem is sourcing all the parts from 1 supplier (who actually has the stuff in stock) so I only have to pay 1 shipping cost. I can't post on the classifieds yet either, anybody have anything laying around?

BTW I am in the Toronto area, Ontario, Canada.

Mouser works well for me, they seem to have everything you want in stock...

To get a good idea of the switches that are offered, at the bottom of this page on Cherry site you can build up part numbers to match what you're looking for...

3-5 MX Plate mounted (colour doesn't matter so much but prefer Blue, Black or Brown) without diodes or LEDs,
   MX1A-E1NN (Panel Mount blues)
   http://ca.mouser.com/Search/Refine.aspx?Keyword=MX1A-E1NN

3-5 MX Plate mounted with diodes
   MX1A-11DN (Panel Mount blacks)
   http://ca.mouser.com/Search/Refine.aspx?Keyword=MX1A-11DN

3-5 MX Plate mounted with diodes and LEDs
   As alaricljs said, they make either LED or Diode, or none, but no switch with both included

3-5 1N4148 OR 1N4001 Diodes
   http://ca.mouser.com/Search/ProductDetail.aspx?qs=HfDODkYFUverVKi/J/e5IA==

Code Y is yellow LED with diode..... do they not make this any more?

[overture1928]

You can't do diodes and leds in the same switch.

What about Code Y? Yellow LED with Diode

[alaricljs]

What about Code Y? Yellow LED with Diode

Well that's intriguing and I never noticed it before... but here's the lead layout in a cherry switch:

A1 A2 C2 C1

Where A is annode, C is cathode, 1 is the diode leads and 2 is the LED leads.  Yes, in a straight line across the switch and completely interfering with each other.

[overture1928]

Need to get my hands on some switches to play around a bit. I need:

3-5 MX Plate mounted (colour doesn't matter so much but prefer Blue, Black or Brown) without diodes or LEDs,
3-5 MX Plate mounted with diodes,
3-5 MX Plate mounted with diodes and LEDs
3-5 1N4148 OR 1N4001 Diodes.

Problem is sourcing all the parts from 1 supplier (who actually has the stuff in stock) so I only have to pay 1 shipping cost. I can't post on the classifieds yet either, anybody have anything laying around?

BTW I am in the Toronto area, Ontario, Canada.

Mouser works well for me, they seem to have everything you want in stock...

To get a good idea of the switches that are offered, at the bottom of this page on Cherry site you can build up part numbers to match what you're looking for...

3-5 MX Plate mounted (colour doesn't matter so much but prefer Blue, Black or Brown) without diodes or LEDs,
   MX1A-E1NN (Panel Mount blues)
   http://ca.mouser.com/Search/Refine.aspx?Keyword=MX1A-E1NN

3-5 MX Plate mounted with diodes
   MX1A-11DN (Panel Mount blacks)
   http://ca.mouser.com/Search/Refine.aspx?Keyword=MX1A-11DN

3-5 MX Plate mounted with diodes and LEDs
   As alaricljs said, they make either LED or Diode, or none, but no switch with both included

3-5 1N4148 OR 1N4001 Diodes
   http://ca.mouser.com/Search/ProductDetail.aspx?qs=HfDODkYFUverVKi/J/e5IA==

You are right I can get everything from mouser, only thing is $20 shipping for such a small amount of stuff is a downer. Wonder if anyone in my area wants to order something with me to split the shipping cost. Anyway I can get out of this junior member faster so I can post on the classifieds?

[overture1928]

BTW I talked to cherry telling them I wanted to get some quick connectors and if I can't find someone who makes them then I need to find someone to manufacture them. The problem was I need to know the exact dimensions of the terminals. I know the height is 3.30mm from their data sheet but nothing else exactly was listed. They sent me the following attachment but I don't exactly get it. Is the thickness 0.3mm +- 0.02mm and is the width in a 4:1 ratio with the height +0.05mm?

[overture1928]

2 More questions

Do I need diodes for my switches?

And does anyone know where this guy got this plate? I know it is a phatom plate but what company actually produced the plate and how can I get the dimensions of this cut-out with the notches so that if I ask another company to make my board with those notches they will know how to do it.

feature=plcp

Diodes remove the problem of key ghosting or masking, which you otherwise would have to solve through software somehow.

I have no idea where the phantom plates were made, but I had a plate made by FrontPanelExpress for a little project that I don't have any pictures of... here's what the plate rendered like though.  I'd be happy to send you the file if you want to look at it.  The design program they use is proprietary, but free... not inexpensive... this little thing was something like $60.

Show Image

Did you just use the dimensions from cherry for the square holes? 0.551" +-0.002 x 0x551" +- 0.002

[regack]

Did you just use the dimensions from cherry for the square holes? 0.551" +-0.002 x 0x551" +- 0.002

I actually set it to .550 x .550 and .0120 corner radius on a 1.5mm thick plate - I didn't specify a tolerance for the holes, but when they came back and I threw the caliper on it, it was pretty much spot on.

[bpiphany]

I had plates cut with a slightly bigger radius (0.4mm if I remember correctly) than the datasheet specifies. I had no problem pushing the switches in. I think I used 0.55" holes as well.

[bpiphany]

BTW I talked to cherry telling them I wanted to get some quick connectors and if I can't find someone who makes them then I need to find someone to manufacture them. The problem was I need to know the exact dimensions of the terminals. I know the height is 3.30mm from their data sheet but nothing else exactly was listed. They sent me the following attachment but I don't exactly get it. Is the thickness 0.3mm +- 0.02mm and is the width in a 4:1 ratio with the height +0.05mm?

I hadn't seen that drawing before. But it is simply the thin flat terminal drawn from three different directions, like drawing are done usually... All numbers are millimeters. The 4 and the 1 as well.