3 The [[http://ergodox.org][Ergodox]] keyboard is an absolutely fantastic design; I use it every
4 day at my office. However, I like to work away from the office
5 frequently, and I thought I might try my hand at designing something a
6 little more portable. The great thing about assembling my Ergodox is
7 that it taught be there's really nothing magical about it; it's just a
8 piece of circuitry with a bunch of switches read by a microcontroller
9 that speaks the USB HID interface.
11 The Atreus is meant to be complementary to the Ergodox as something
12 smaller, cheaper, and more travel-friendly. The case measures 25x11cm
13 and lacks even a number row, relying heavily upon the fn key. There is
14 no PCB in this design, requiring [[http://deskthority.net/workshop-f7/brownfox-step-by-step-t6050.html][a manual matrix wiring approach]].
15 However, given that there are only 4 rows and 10 columns, this isn't
16 as daunting as it could be. It also allows for quicker iteration on
17 design changes since alterations only require cutting a new case.
19 I've seen a number of existing DIY 40% keyboard designs, but all of
20 them stagger the rows, which I find very annoying now that I've gotten
21 used to the columnar layout of the Ergodox. In addition, all the
22 designs I've seen waste a lot of room on the space bar, failing to
23 take into account the fact that the thumb is the strongest and most
24 versatile of the fingers. This design avoids both these problems.
30 Only a handful of punctuation marks (and no digits) available
31 unshifted, and all the modifiers are on the bottom row.
33 : q w e r t || y u i o p
34 : a s d f g || h j k l ;
35 : z x c v b || n m , . /
36 : shift super tab bksp ctrl fn || space alt enter esc pgup pgdn
38 The numbers and most punctuation are on the fn layer:
40 : 1 2 3 4 5 || 6 7 8 9 0
41 : ! @ # $ % || ^ & * ( )
42 : _ - = + / || ? { } [ ]
45 I type in Dvorak but prefer to do the remapping in software rather than
46 hardware so I don't have to change layouts when I switch to my
47 laptop's internal keyboard.
53 This layout has five modifiers and 37 non-modifiers.
55 I strongly prefer the feel and sound of tactile [[http://www.digikey.com/product-detail/en/MX1A-E1NW/CH197-ND/20180][Cherry MX blue]]
56 switches for typing. However, I like having linear switches on the
57 modifier keys (ctrl, alt, super, shift, and fn). [[http://www.wasdkeyboards.com/index.php/products/keyboard-parts/cherry-mx-red-keyswitch-mx1a-l1nn-linear.html][Cherry MX red
58 switches]] are nice and light but are difficult to find. [[http://www.digikey.com/product-detail/en/MX1A-11NW/CH160-ND/91134][Cherry MX black
59 switches]] are cheaper and easier to source, but may be too heavy,
60 especially for keys under pinky fingers.
62 One trick is take the springs from some of your blue switches and
63 trade them with the springs from your black switches. The blacks then
64 become the equivalent of reds, and the blues become MX green switches,
65 which are a heavier variant of blues. These are typically used for
66 space bars on boards that otherwise use blues. They could be suitable
67 for non-modifier thumb keys.
69 **** Recommended switch types for bottom row
85 In order to avoid ghosting, each switch needs a [[http://www.digikey.com/product-detail/en/1N4148TR/1N4148FSTR-ND/458811][diode]].
89 I'll be using a Teensy 3 since I have one on hand, but an [[https://www.adafruit.com/products/1315][Arduino
90 Micro]] or [[http://www.pjrc.com/teensy/index.html][Teensy 2]] would work too.
94 This [[http://keyshop.pimpmykeyboard.com/product/dsa-pbt-blank-sets][DSA-shaped base set]] has 52 1x keys plus a few extras we won't use.
98 Layered laser-cut acrylic; see [[file:case.svg][case.svg]]. 2mm for the bottom and top
99 layers, 6mm for the others.
107 - 37 MX Blues @ $1.00
110 - Base keycap set: $18.00
113 =(+ 37 (* 5 0.8) (* 42 0.052) 18 16 11)= -> 88.18 plus shipping and cutting
115 - Digikey (switches and diodes) shipping: $5.32 in the US
116 - Signature Plastics (keycaps) shipping: ??
117 - Acrylic materials: $11 (cheaper if transparent acrylic is used)
118 - Acrylic laser cutting: ??
122 Copyright © 2014 Phil Hagelberg
124 Released under the [[https://www.gnu.org/licenses/gpl.html][GNU GPL version 3]]