Arch 40

Arch 40

Case Renders:

Switch Plate:

40% Ortholinear + Columnar Stagger Keyboard

• Inspired by the Ergodox, Atreus, Iris, Corne, and probably others

• Design goals:

  • Efficiency and minimalism of a 40% form factor
  • Ergo benefits of tilted columnar stagger layout
  • Ease of use coming from ANSI style layouts
  • Simplicity of a non-split keyboard
  • Compatability with Ergodox style keysets
  • Compatible with Cherry MX, Alps, and Kailh Choc switches

Assembly:

• Stacked acrylic layer case, acrylic/metal switch plate
  • Layer dimensions and path lengths are outlined in path_length.md
  • Alternatively, there is a 2-part case in ./cad_files/stl_files/3d_print_case designed to be 3D printed and fastened together with machine screws
• Can be built with a PCB and microcontroller, or can be handwired with a microcontroller
• Files for laser cutting by Ponoko/other services in ./illustrator_files and ./inkscape_files

  • ./illustrator_files includes case layer DXF files imported into Adobe Illustrator at 1:1 scale with units in millimeters

    • final_cut_layout.eps is Ponoko's P3 size template with case layers, without plate
      • Use this if you choose to go with a metal plate
    • final_cut_layout_plate.eps is Ponoko's P3 size template with case layers, with plate
      • Use this if you choose to go with an acrylic plate

  • ./inkscape_files includes pdf-compatible Adobe .ai files as well as .SVG files of the case layers and plate

Component list:

• Acrylic case layers + plate
• PCB (optional, can be handwired as well)
  • Pro Micro (PCB is designed to use this microcontroller)
  • Teensy2.0 (if handwiring and not using PCB)
• (49) Cherry MX style switches
• (1) 2u Cherry style stabilizer
  • Plate-mounted works perfectly with 1.5mm metal switch plate
  • Requires some modification to work properly with 3.0mm acrylic plate
• Adafruit USB-mini breakout board (or a simple female USB-mini)
• WS2812B LED strips (optional)
• (49) 1N4184 diodes
• M2 Standoffs and screws
  • 5mm screw length
  • 10mm standoff length for use with a 1.5mm metal plate
  • 12mm standoff length for use with a 3.0mm acrylic plate

Case Stack Order:

1. arch_40_case_layer0
2. arch_40_plate
3. arch_40_case_layer2-3
4. arch_40_case_layer2-3 (repeated)
5. arch_40_case_layer4
6. arch_40_case_layer5

• Note: arch_40_case_layer2-3 is intended to be used twice, it contains the cutout for the USB connection

PCB:

Revision history:

• rev 0: prototype, designed by ibnuda
• rev 1: better case fitment, functionally same as rev 0
• rev 1.1: added support for MX, Alps, Kailh Choc switches

• QMK files for PCB firmware in ./firmware/qmk_files
• PCB can be made by sending the zipped gerber files in ./pcb/gerbers/arch_40_rev1.1_gerber.zip to a PCB prototyping service such as JLCPCB
• Note: The Pro Micro controller needs to be soldered onto the PCB as close as possible, need to remove the spacers on the headers of the Pro Micro

Pro Micro Pinout:

• Diode direction: row to column
• Column 0 = ESC key column
• Row 0 = QWERTY row

Rows:              Columns:                            LED:
-----------------------------------------------------------------
r0 : D3            c0 : F4         c6 : B2             vcc : VCC
r1 : D1            c1 : F5         c7 : B6             gnd : GND
r2 : D0            c2 : F6         c8 : B5            data : D2
r3 : D4            c3 : F7         c9 : B4
                   c4 : B1        c10 : E6
                   c5 : B3        c11 : D7
                                  c12 : C6

Handwiring:

Matrix:

Teensy2.0 Pinout:

• Diode direction: column to row
• Column 0 = ESC key column
• Row 0 = QWERTY row

Rows:               Columns:                            LED:
-----------------------------------------------------------------
r0 : F0             c0 : F7         c6 : C6             vcc : VCC
r1 : F1             c1 : B6         c7 : D3             gnd : GND
r2 : F4             c2 : B5         c8 : D2            data : B1 
r3 : F5             c3 : B4         c9 : D1
r4 : F6             c4 : D7        c10 : D0
                    c5 : C7        c11 : B7

Wiring Example:

Wiring Example With Underglow LED's:

Firmware Flashing:

PCB Builds:

Linux:

• The Pro Micro controller can be flashed with avrdude

  • Navigate to the ./firmware directory to flash the arch40firmware_pcb.hex file:

  $ avrdude -p atmega32u4 -P /dev/ttyACM0 -c avr109 flash:w:arch40firmware_pcb.hex

  • Or to the ./firmware/qmk_files to flash the arch40_promicro_default.hex file

  $ avrdude -p atmega32u4 -P /dev/ttyACM0 -c avr109 flash:w:arch40_promicro_default.hex

• They are the same keymap, the former was created with Keyboard Firmware Builder, and the latter with QMK

Windows/MacOS:

• Can be done using QMK Toolbox

LED Backlighting:

• Default firmware arch40firmware_pcb.hex and arch40_promicro_default.hex includes configuration for WS2812B LED backlighting strips
  • The data pin for the LED's is set to pin D2 on the Pro Micro
  • Default 12 LED quantity, 10 backlight brightness levels, variable color hue
  • To change the LED configuration:
    1. The arch40firmware_pcb.json file can be uploaded to Keyboard Firmware Builder and edited/recompiled as desired
    2. The QMK source files can be edited manually in a text editor

Handwired Builds:

• Linux:
  • The Teensy2.0 controller can be flashed with the teensy-loader-cli

$ teensy-loader-cli --mcu=atmega32u4 -w -v ./firmware/arch40firmware_hw.hex

• MacOS/Windows:
  • Can be flashed with the Teensy Loader Application
  • Or can be done using QMK Toolbox

LED Backlighting:

• Default firmware arch40firmware_hw.hex includes configuration for WS2812B LED backlighting strips
  • The data pin for the LED's is set to pin B1 on the Teensy2.0

Note:

• Kerf of plate and case layers is set to 0.15mm (typical for Ponoko/ Laserboost/ Lasergist)

To-do:

• Add image of default keymap

Model was created in Solidworks, then exported as STL/DXF. Feel free to use/modify/redistribute.