WHATI'm building a custom ergonomic keyboard: its wireless, will work with any device ( android, ios, mac, pc), split yet no cable, low cost $250 ish, somewhat inspired by a myriad of inspiring alternative keyboards: touchstream, kineses, ergodex and DataHand, maltron.
It's named the 'Conchi' after it's conch shell like appearance + HCI (human computer interface). initial pass is raw material, exposed wires, polished style as permitting.
WHYMore
The core motivation is to help combat my chronic tendonitis/tendonosis, acquired being a software developer consultant with long hours, fast typing speed, and enable me to continue working longer as still how I support myself
There are 2 phases of this project:
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1) short term, the primary goal of this project is to replace the BTC 'mini multimedia keyboard', the model I've been using for about 6 years (going through one every couple years), and keeping the same 86 key (tenkeyless) layout that has been baked into my muscle memory, so I can keep working without so much effort learning a new layout, and simultaneous combating tendonitis/RSI. ASAP. In a typical workweek I spend a fair amount of time recovering from using even this relatively low force (60-65g) keyboard, and other switches are only marginally better, while 8g is in a league all it's own, being less than the typical force a finger puts at rest.
2) longer term, an experimental DataHand like approach, with thimble like fingerwells for minimum travel in varied directions. With 5+ keys per finger, likely using pressure sensitive rather than switches.
KEYs using alternative micro SWITCHESMore
This is one of most important parts. Our fingers receive a tremendous amount of work (abuse?) from hammering these tiny nails into the keyboard over vast distances, probably the equivalent of thousands of miles of running over a decade. I'll be using super low force subminiature microswitches, that have 1/8th the force at 8g of typical 65g+ force keystroke activation, and have it modelled after my hand and range of finger travel.
I have done significant research on keys before selecting micro-switches (inspired by Tim Tyler's experiments
http://mykeyboard.co.uk/microswitch/ though we differ in approaches).
About a decade ago having my first flareup of tendonitis that didn't go away after a weekend, I tried every keyboard at every computer stores in the area, before I decided on the BTC which was accessible at Fry's electronics. Prior to that, I used an exotic Fingerworks Touchstream for years, which although is 'zero force' but like hitting the flat screen of an ipad, it really isn't ergonomic, particularly on the back of the hand having to keep the hand above the surface from touching it accidentally, as well they are finicky, break and now can't be repaired. I have played with light keyboards (laser, lightio), virtual keyboards on ipad/android tablets, my fingers hurt using them for any prolonged use as well as the lack of feedback are deal killers. 4th generation haptics will eventually improve this, but there needs to be a full feedback loop of finger hitting the switch but not activating it, intital resistance pressing to start activation, a breakaway as it's activated with a progressive break to avoid hard bottoming out, and ideally a restorative force (like a trampoline or piano hammer weighted key) This isn't really possible without a physical mechanism.
To explore, I ordered a sampler of Cherry MX and some other keyboard switches, to compare in a real world test setting.
- 0 force optical proximity sensors
- 8g, 10g, 16g, 20g Omron subminiature lever microswitches.
- 35g Qateron Clears,
- 45g+-65g Cherry Switches, linear and tactile
- 60-65g scissor action and the cheapo BTC mini 86 keyboard that has been my workhorse for years,
I measured their activation force using a kitchen scale a bolt loaded up with washers till it could no longer statically support the load.
Next I rotated through them hacking into a Kensiginton 4 button trackball,
primary goal replacement of my left and right mouse button, to figure out what worked the best, as the built trackball clicking is very heavy like 90g+ force, and that is one of the biggest pain points I have, the right thumb, click, double click, click to hold and drag, select constantly throughout the day, which sometimes wakes me up at night from the pain. This 1 minute tour
capturedvideo.MOV (6035.1 kB - downloaded 150 times.) shows the layout, all four buttons ended up being used, 3 on thumb (click, double click, middle click), one on pinky ( right).
That revealled I liked the 8g-16g Omron most, and found 20g too hard for ideal, and the 8g so far are working the best for me in the trackball in a side clicking manner, even though it's most prone to accidental clicks placing the hand in it. The optic proximity sensor worked but had the issue with you can't rest your finger near it, creating a different form of work being done, and there is no feedback loop as to where/when you are/click.
The Omron microswitches are available at very different forces, in the same standard size, and a couple different ways to actuate it from a plunger, to a lever, to variations on the lever (roller). These are considered subminature, are smaller and longer than a normal key switches, and the layout I'll do will end up being more compact likely than a traditional keyboard, but fatter columns, so that more macros can be accessed. They run about $1.80 to $2.50 each depending on who you order from and what quantity. I ordered 150 of them from Newark in the UK as they have significantly cheaper pricing than Mouser, Parts Express.
150 switches for:
86 keys for the first conventional one
50 for the datahand like one.
extras for things that go wrong or hacking.
So far I won't need key caps, the lever is out of steel on these microswitches is big and smooth enough to work well. Though I am experimenting with a dab of silicon to glue the lever to the switch as it can ocassionally lift up which makes it feel ...wrong.
CONTROLLER
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Initially I'll be using some cheap $29, Bluetooth keyboards off alibaba hacked apart as bas, if that doesn't work or for a more powerful version I'll be using two Teensy 2.0++ one for each hand as I want to be split handed, and direct wire to avoid ghosting/need for diodes, lots of unnecessary soldering, and matrix complexity, plus it has USB mouse and keyboard emulation and is trivial to program ...first key microswitch triggering os key or mousem example took about an hour, having never used an arduino before.
I'm excited by the wireless and battery powered potential, to help increase ergonomics by easily repositioning it, vs being locked into generally arms in front which has lead to chronic pain aside from fingers, and taking it on the road, with whatever devices I have on hand or are to come ( unlike ps2)
I had considered using one of my existing defunct keyboards or getting a wireless keyboard just for the controller+wireless+battery, but the mini keyboards are almost monolithic in construction with dual sided ribbon tape and tight traces that seem overly complicated to hack ( though after trying several found an ok candidite for a basic version), as well there is flexibility in Teensy code to expand to mice/footswitches, chords etc. e.g. in a finger well with N, S, E, W buttons, pressing N+E in near the same time might translate to a single keystroke of NE. Or two fingers both pressing E at the same time might be copy, and 2 W might be paste, similar to the touchstream's cool pallette of these common operations.
WIRING
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I'm going to use standard twisted wire hand soldered direct to the teensy 2.0++, and skip the PCB board as I'm going for curved, quick and dirty as I know these projects are highly iterative, you don't know what's needed exactly till actually using it. I hope my soldering skills are up to the task
Thankfully as it's only 86 keys it's not that many solder joints actually.
I'll be using a breadboard for the first pass.
MOUNT
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I'll be using Polycaprolactone (hot water moldable thermoplastic) aka Shapelock, Instamorph, I've build many grips/mounts out of this material and it's strong flexible easy to rework with a hot air gun, this latter comes in super handy as you find the thing needs to be just slightly different. As a bonus, the switches seem to bond with the plastic when it's hot, without damaging them, so that is how I'll mount the microswitches in the curves sculpted after my finger/hand travel.
This will accompany a zero gravity recliner "throne" I'm making out of Kee Klamps, and memory foam. To accompany the existing sit, stand, lie, treadmill, whatever position, pipe desk with 4 monitors and LCD monitor arms.
---------------------------------------------DEV LOG SUMMARY ------------------------------------------------------
3/20/2015
At this stage i have ordered the parts, which should arrive in the next week or 2.