keyboard with track point
By Philipp Schönberger
I am a software programmer so the main part of the workday I am typing on my keyboard. At work unfortunately the only provide the cheapest HP keyboard you could image. It is a nightmare. After 3 months typing on these I bought me an keyboard myself.
Since I am used to a track point from my x230 notebook I searched for a keyboard which had also a track point for the desktop.
Sadly these kind of keyboards are rare. Since I where a student at this time I ordered me an IBM keyboard. The feeling was nice and I like the track point feature of it. However after 1 year of using this keyboard I broke it at multiple keys. These keys stopped working and the overall feeling was not the same like a new keyboard. This is a cause of the membrane keyboard type. They age quite fast if used extensively. Also the pressure point of the activation changes.
Therefore I searched for an alternative with mechanical switches. They shall last much longer and in case they are broken I could exchange them by soldering new one in.
Therefore I ordered the CM Storm Rapid-I with red key switches. The red cherry switches where linear and do not have a feedback bump. The overall feeling of these keys where nice but after a time I disliked the missing feedback. Also I missed a track point on these keyboard.
Therefore I started a project to integrate a tracepoint into the keyboard, which was not available any where else except the old IBM keyboard which only had an English key layout.
I disassembled the keyboard and did take a look at the PCB. On close look between the keys
the PCB only had a ground plane but not real signal traces going around.
Therefore I thought of drilling through the PCB and place a long stem with a track point underneath.
I disassembled an old keyboard from an T40 and recycled the track point from it.
The tack point itself is just a small PCB with a cross shaped cutout and some glued strain gauge in the
4 directions. The secondary PCB is just a fast ADC and a 3 button input converter to a PS2 interface.
Therefore I just had to connect some additional mechanical switches to the secondary PCB and connect it to a pc. Unfortunately the PC's nowadays do not have a PS2 so common any more therefore I wanted a PS2 to USB converter. After short research I found the Teensy2.0 which was capable to emulate a USB device and also is capable to run TMK software which is capable of PS2 reading.
The first test assembling I tried the whole system and it worked like a charm.
Now I got the best of both worlds a track point and also a full mechanical keyboard. The last thing missing was the feedback. So I resolved my wrong order by soldering brown Gatheron which are close to the Cherry brown.
I took it a work and I was happy with it. Unfortunately my office partner not :D So I tried to silence the hell out of my keyboard. I ordered zeal silencer clips and added 2 O-rings. Also I replaced the keycaps with PBT which are much harder plastic and do not wear out or get shiny like the ABS ones. Also I replaced the keyboard case with an aluminum CNC case. This mad the keyboard much heavier which dampened the noise from the desk, removed any vibrations. Also from esthetic's point of view the keyboard looked and felt much sturdier and from high quality.
To round up the feeling I added some lube to each switch and tada the sound and feeling of the keyboard was a dream. Since I have now 2 USB devices in on (Teensy and the original CM Strom) I replaced the USB cable with a own 8 pol cable with two USB plugs and a textile sleeve to get a awesome optic.