*** Keycaps
-This [[http://keyshop.pimpmykeyboard.com/product/dsa-pbt-blank-sets][DSA-shaped base set]] from Signature Plastics has 52 1x keys plus a
+This [[http://keyshop.pimpmykeyboard.com/product/dsa-pbt-blank-sets][DSA-shaped base set]] (spherical indentations on the key, same
+profile for each row) from Signature Plastics has 52 1x keys plus a
few extras we won't use. It claims on that page to contain only one
deep key, but my shipment contained two, which I put under the index
finger keys to help guide your hands without looking. However, it only
the spacer that goes under the fourth, which is the plate on which the
switches are mounted. These should be cut in 6mm, especially the
spacer, which needs to be at least as thick as the micro USB cable you
-connect to the microcontroller. The switch plate could be thinner.
+connect to the microcontroller. The switch plate could be thinner,
+but not under 3mm.
On a 100W Epilog laser, the 3mm layers cut in about a minute and a
half. I did a run with 6mm acrylic of the other layers which took
nearly 6 minutes.
-One thing to watch for is that the screw holes unfortunately are not
-symmetrical. So before the switches get mounted, it's important to
-ensure that the switch plate is right-side-up.
-
** Firmware
My [[https://github.com/technomancy/tmk_keyboard/tree/atreus][fork of the tmk firmware]] has support for the Atreus
- 50 MX Blue switches: $29.00 (mechanicalkeyboards.com)
- 50 diodes: $3.45 (radio shack, should be able to buy in-person)
-- Base keycap set: $18.00 (signatureplastics.com)
+- Base DSA keycap set: $18.00 (signatureplastics.com)
- Teensy 2: $16 (pjrc.com or mechanicalkeyboards.com)
- Acrylic materials: $11
- Acrylic laser cutting: 7.5 at $3/min (varies by thickness of acrylic)
- 5 MX Black switches: $8.50 (optional)
- 5 MX Red switches: $10.00 (optional)
+- additional 1.5x DSA keycap: $1 (optional)
=(+ 29 3.45 18 16 11 (* 3 7.5))= $99.95 plus tax/shipping
- Signature Plastics (keycaps) shipping: $8.00
- PJRC (teensy) shipping: $3.03
-** Other Tools:
-
-You'll need a soldering iron, solder, a multimeter, wire, wire
-strippers, and a USB micro cable. You'll also need seven M3 machine
-screws with nuts; the length of the screws depends on the thickness of
-the acrylic you use.
+** Other Tools
+
+You'll need a soldering iron, solder, a glue gun, a multimeter, wire,
+wire strippers, and a USB micro cable. You'll also need seven M3
+machine screws with nuts; the length of the screws depends on the
+thickness of the acrylic you use.
+
+** Assembly
+
+Once you have all the parts, the first thing to do is glue the
+switches to the switch plate since there's no PCB to hold them in
+place. Be aware that the screw holes unfortunately are not
+symmetrical, so before inserting the switches it's important to ensure
+that the plate is right-side-up. Use a drop of hot glue on the top and
+bottom of each switch to affix it in place.
+
+Once the switches are in place, the matrix must be created. I
+recommend getting red wire for the rows and black for the columns. The
+rows need eight strands of wire with the insulation exposed at
+intervals matching the spacing of the switches; see [[https://secure.flickr.com/photos/43319799@N00/12669228444][this photo]] for
+details. You could also just use many short stripped segments of wire
+instead of a contiguous piece. Most of the row wires will need four
+segments of insulation, but you'll need two with five for the rows
+with the inner thumb keys. Physically the inner thumb keys look like
+two additional columns, but logically they are treated as if they're
+in the same column with the left one in row 3 and the right one in
+row 4.
+
+The exposed sections of row wire should be connected to the higher of
+the pins on the switch using a diode. Be aware that diodes are
+directional! The band around the diode should point to the top of the
+board. Take care with the upper row that you don't let the wire go too
+high; avoid getting in the way of the spacer layer. Once the
+rows are wired, the remaining (negative) pin of each switch should be
+wired into the negative pin of the switch above and below it. Use
+black wire. This should be slightly easier since no diode is
+necessary. [[https://secure.flickr.com/photos/43319799@N00/12668880863][This photo]] shows the completed matrix for one side. Test
+each row and column as you go with a multimeter. You should be able to
+get continuity from row to column when the corresponding switch is
+activated.
+
+After the matrix has been wired on both sides, the next step is to
+connect the microcontroller. The TMK firmware has the rows in pins D0,
+D1, D2, and D3 of the microcontroller. You'll need to connect the rows
+from both the left and right sides into the proper pin. There are more
+columns than rows, so I used ribbon cable to bring the column
+connections back to the microcontroller from the outside in. The
+columns go to pins F0, F1, E6, C7, C6, B6, D4, B1, B0, B5, and
+B4. It's important to realize that when you flip over the board
+in order to solder it, you have to flip over the schematic in your
+mind too. If you count your columns from the left, you'll get them
+backwards. (Which I actually did for the first half.) You can see [[https://secure.flickr.com/photos/43319799@N00/1270569443y3][my
+wiring of the microcontroller]].
+
+Once you've wired one side of the microcontroller in, it would be a
+good time to test it. You'll need to install the [[http://www.pjrc.com/teensy/loader.html][teensy loader]] and
+point it at the .hex file from the tmk firmware build. Then hit the
+physical reset button on the Teensy itself. At this point you should
+be reading real keycodes from the half of the keyboard that you've
+wired. Once you've confirmed that's working, continue with the other
+half. Then screw the other layers in place and you're all set!
** Cost-saving Options
projects / atreides.git / commitdiff