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 tab super ctrl bksp || space alt enter esc fn
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 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 However, I like having linear switches on the modifier keys (ctrl,
57 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 switches]] are nice and light
58 but are difficult to find. Cherry black switches are cheaper and
59 easier to source, but may be too heavy, especially for keys under
62 This layout has five modifiers and 35 non-modifiers.
66 In order to avoid ghosting, each switch needs a [[http://www.digikey.com/product-detail/en/1N4148TR/1N4148FSTR-ND/458811][diode]].
70 I'll be using a Teensy 3 since I have one on hand, but an [[https://www.adafruit.com/products/1315][Arduino
71 Micro]] or [[http://www.pjrc.com/teensy/index.html][Teensy 2]] would work too.
75 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.
79 Layered laser-cut acrylic; see [[file:case.svg][case.svg]]. 2mm for the bottom and top
80 layers, 6mm for the others.
91 - Base keycap set: $18.00
94 =(+ 35 10 (* 40 0.052) 18 16)= -> $81.08 plus shipping and acrylic
96 - Digikey (blues and diodes) shipping: $5.32 in the US
97 - WASD (red switches) shipping: ??
98 - Signature Plastics (keycaps) shipping: ??
99 - Acrylic materials: ??
100 - Acrylic laser cutting: ??
104 Copyright © 2014 Phil Hagelberg
106 Released under the [[https://www.gnu.org/licenses/gpl.html][GNU GPL version 3]]