At some point ago, my best friend had some youtube videos in the background (as usual) and one of the videos was talking about a vertical reed switch keyboard (I don't remember if the video was covering many unique types of mechanical keyboard switches or some older mechanical keyboard switches), and it sounded nice since reed switches last much, much longer than Cherry MX or Romer-G switches; and are hermatically sealed, so that the contacts are unaffected by the environment.
My obvious problem was that the reed switch was vertical, meaning it made the keyboard quite tall, and after a bit of poking on Mouser, I was quite sure i could make a "horizontal" reed switch keyboard ("parallel" might be a better word?). The two cheapest ones were a through-hole variant and and SMD variant, and while the through-hole variant could be utilised however I'd like, it had a specific way to form the leads. The problem with the SMD variant was that the contacts were perpendicular from the board according to Digi-Key's image (more on this in a bit).
I also looked at magnets and found a 1/8 inch diameter, 3/8 inch length rod, which I decided on, since it would be the smallest size in the X-Y plane, and that it was going to go through a hole in the PCB to close the reed switch contacts (the switches would be on the underside of the PCB. I began designing the board, obviously starting with adding the parts to the library, and ended up adding the hole to the reed switch part for less placement hassle. I also used a Teensy 2.0 as the controller, since it's it's a popular option for custom keyboards, and also used some zener diodes for anti-ghosting.
When I went to buy the parts for my "Dual 3DS Charger", I also grabbed the reed switch so I could get a better idea of what I was dealig with. When I looked at the switch, it seemed like the contacts parallel to the board, and after carefully getting it out of the tape, it was easier to confirm. Digi-Key's images are usually of the item itself for that specific configuration, but that was obviously not the case this time, and because the datasheet didn't say anything else, Digi-Key's image was all I really had to go off of.
At the least, I didn't finish or order the test PCB, so I was able to fix what I needed to and finish the design of the test board. Also with this, I also went back to look at magnets and wrote down which I think might be suitable, regardless of material. I also ordered a couple things I would also need with the test board from mouser along with some contacts for the Dupont connectors (used for stuff like the motherboard USB 2.0 headers) and some contacts for the Molex connectors used for motherboard CPU/CASE fan headers.
I've not gotten around to soldering the test board together at the time of this writing, but I have (maybe) started the order process of the candidate magnets (along with some other items to meet the minimum.
As far as the new design goes, I'm still keeping the switches underneath the PCB so that they don't get damaged as easily, but removed the hole to make it a bit easier to run the traces. I've arranged the parts, from what I remember, but haven't ran the traces yet.
Before I forget the design is for an "extended numeric pad", so the "10-key" section of a normal keyboard with a few extra buttons (shift, tab, backspace), since I have a limited board area in EAGLE to work in.
For the test, I'll be seeing the distances that each magnet closes and releases the contacts, and the shorter that distance, the better.
The other thing I want to try to do is have a minimal "over travel" distance after the switch has been activated, considering that all "standard" keyboards are just membrane/rubber dome and activates when the key is bottomed-out. Cherry MX switches generally activate at 2mm and bottom at about 4mm (I'm ignoring the speed silver), which is a bit annoying for people like me who have a "standard" keyboard at work and mechanical keyboards at home since I'm not able to fully learn to release the keys after actuation.
I also want to make the stem compatible with Cherry MX keycaps, so that it can use existing keycaps instead of having to find some place to make a custom set (nevermind that the magnet mechanism has to be made).
I looked at springs at one point from Lee Springs (since my work ordered from them), but put it on hold for now since I haven't any ideas of the mechansim itself (and that their website's not entirely friendly if you're not sure what you're looking for).
I wanted to to controllable RGB backlighting, but it's easier said than done, since i would have to have some sort of complex multiplexing algorhythm while keeping the current at reasonable levels; I'll stick with single-colour lighting since it'd be much easier to multiplex. I wanted to try to make it compatible with PS/2, but I think I wouldn't be able to backlight it because PS/2 has a very limited current output.
My best friend also would like to try to make a side business with these once everything's worked out, and so I had thought of a few different key-count configurations along with different selling configurations. Besides the possibility of it actually happening, there's also the plausibility of popularity, since it's a fairly niche item. Though if it does happen, I did also chat with him that we would be selling all the parts, so if someone breaks a stem or loses a magnet, they can just buy another instead of having to send the entire keyboard in like most major companies (thanks Logitech for trying to get me to send my solar keyboard in because one of the scissor jacks broke...).
The "extended numeric pad" would take the standard layout of the 10-key and add a long key like the + to the left of the 1 and the 0, which would be Shift; one to the right of the enter key, which would be Tab; and one to the right of the - and + keys, which would be Backspace (also Num Lock would change to Delete). The point of this is to facilitate one-handed spreadsheet operation since Tab moves the cursor rightward, Enter moves the cursor downward, adding Shift to either of the previous combinations would move the cursor in the opposite direction, and the Backspace and Delete keys would also add to the value of keeping the hand stationary. While some peripheral manufacturers usually split 0 into 0 and 00 or 000, I find it a bit pointless since it's kidna hard to hit. For toggling Num Lock, I'd probably have Shift+5 as the toggle, and maybe have Shift+(key) to activate the non-locked function without turning Num Lock off (so Shift+9 would be Page Up, for example).
I ended up finding out the source of Digi-Key's wrong image - it seems like they pulled it from the datasheet, which is an incorrect depiction. I've also been looking at other reed switches on Mouser and Digi-Key which are cheaper and/or smaller than the one I chose, so I may be spending more time on choosing a reed switch and magnet combination.
I did design the mechanism in CAD, but eventually decided to make the mechanism rotate the magnet instead to make it easier to control the magnet, but haven't attempted to figure out the model in CAD.
Also from using Century Spring for a Cherry MX mod, I'll probably go with them instead of Lee Spring.
Project is on (maybe permanent) hiatus since it's still a lot of work and money for something super niche.
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