Overview

The orch is a keyboard PCB.

It has:

• A mostly ortholinear layout
• Key sizes that fit most GMK keycap sets
• 1.25u super/meta/command keys
• 19mm switch spacing
• An arrow key cluster
• A function key column
• USB-C
• A rotary encoder
• No stabilizers unless you want one for a 2U spacebar
• Optional 2U spacebar or 2 1U keys

Key Layout

The key layout looks like this. (Thanks to Keyboard Layout Editor for the image.)

This is the corresponding data for pasting into Keyboard Layout Editor:

[{x:0.25,c:"#393b3b",t:"#9065c7",a:6,w:1.5},"Tab",{c:"#727474",t:"#c6c9c7",a:4,f:5},"Q","W","E","R","T","Y","U","I","O","P","{\n[","}\n]",{w:1.5},"|\n\\",{c:"#393b3b",x:0.25,t:"#c6c9c7",a:4,f:3},"Page\n\n\n\n\n\nUp"],
[{t:"#689b34",a:6,w:1.75},"Control",{c:"#727474",t:"#c6c9c7",a:4,f:5},"A","S","D","F","G","H","J","K","L",":\n;","\"\n'",{c:"#393b3b",t:"#689b34",a:6,f:3,w:1.75},"Function",{x:1,t:"#c6c9c7",a:4},"Page\n\n\n\n\n\nDown"],
[{t:"#ee6d00",a:6,w:1.75},"Shift",{c:"#727474",t:"#c6c9c7",a:4,f:5},"Z","X","C","V","B","N","M","<\n,",">\n.","?\n/",{c:"#393b3b",t:"#ee6d00",a:6,f:3,w:1.25},"Shift",{x:2.5,t:"#dd1126"},"Code"],
[{y:-0.75,x:13.25,t:"#c6c9c7",a:4,f:5},"&uarr;"],
[{y:-0.25,x:0.5,t:"#ee6d00",a:6,f:3},"Fn",{t:"#0084c2"},"Ctrl","Alt",{t:"#dd1126",w:1.25},"Code",{t:"#0084c2"},"Code",{c:"#727474",t:"#000000",a:7},"","",{c:"#393b3b",t:"#0084c2",a:6},"Code",{t:"#dd1126",w:1.25},"Code",{t:"#0084c2"},"Alt","Ctrl",{x:3.5,t:"#dd1126"},"Code"],
[{y:-0.75,x:12.25,t:"#c6c9c7",a:4,f:5},"&larr;","&darr;","&rarr;"]

PCB Renders

Case

Case files are in the case directory and include a cutout for the rotary encoder. The "closed" layer requires some dremeling or filing to make room for the USB connector. Thanks to the swillkb Plate & Case Builder. There are two bottom case files included. One of them has smaller holes that are meant for tapping (to secure the screws directly into the back case layer), and the other has "open" holes that an M2 screw will fit through (to secure the case together with nuts).

Schematic

There is a PDF of the schematic here.

AVR Notes

These are just some notes on programming the ATmega32U4. The datasheet is here.

Programming

ISP headers are included in the "No Legs" Tag-Connect format. You need a Tag-Connect cable and retaining clip board to connect to it. For example, if you have an AVRISP mkII programmer, you need the "No Legs" cable and the retaining clip board.

Fuses

Default values are:

E:F3, H:99, L:5E

Extended

Name	Bit	Value	Status	Reason
-	7	1	Unprogrammed	Unused
-	6	1	Unprogrammed	Unused
-	5	1	Unprogrammed	Unused
-	4	1	Unprogrammed	Unused
HWBE	3	0	Programmed	Pin used to force bootloader after reset
BODLEVEL2	2	0	Programmed	4.3V brown-out reset threshold
BODLEVEL1	1	0	Programmed	4.3V brown-out reset threshold
BODLEVEL0	0	0	Programmed	4.3V brown-out reset threshold

Hex value is F0.

High

Name	Bit	Value	Status	Reason
OCDEN	7	1	Unprogrammed	OCD disabled
JTAGEN	6	0	Programmed	JTAG enabled
SPIEN	5	0	Programmed	SPI enabled
WDTON	4	1	Unprogrammed	Watchdog timer in interrupt mode
EESAVE	3	1	Unprogrammed	EEPROM preserved on chip erase
BOOTSZ1	2	0	Programmed	Default maximum boot size
BOOTSZ0	1	0	Programmed	Default maximum boot size
BOOTRST	0	1	Unprogrammed	4.3V brown-out reset threshold

Hex value is 99.

Low

Name	Bit	Value	Status	Reason
CKDIV8	7	1	Unprogrammed	Don't divide clock by 8
CKOUT	6	1	Unprogrammed	Don't output clock
SUT1	5	0	Programmed	Crystal oscillator with BOD enabled
SUT0	4	1	Unprogrammed	Crystal oscillator with BOD enabled
CKSEL3	3	1	Unprogrammed	Low power 16MHz crystal oscillator
CKSEL2	2	1	Unprogrammed	Low power 16MHz crystal oscillator
CKSEL1	1	1	Unprogrammed	Low power 16MHz crystal oscillator
CKSEL0	0	1	Unprogrammed	Crystal oscillator with BOD enabled

Hex value is DD.

Setting Fuse Values

avrdude commands to set the fuse values with an AVRISP mkII programmer:

avrdude -p m32u4 -c avrispmkII -U efuse:w:0xF0:m
avrdude -p m32u4 -c avrispmkII -U hfuse:w:0x99:m
avrdude -p m32u4 -c avrispmkII -U lfuse:w:0xDD:m

Note that the extended fuse will always show as C0 with avrdude (despite the datasheet saying that the first four bits are unprogrammed/1111).

You may need to erase the chip before you set the fuse values:

avrdude -p m32u4 -c avrispmkII -e

The first time flashing should be done with a programmer like the AVRISP mkII and you should compile QMK to include the bootloader in the firmware file (using :production). I have a fork of the qmk_firmware repository here that I may or may not try to get merged at some point.) To compile the orch branch with the QMK CLI:

qmk compile -kb orch -km default:production

I've had luck setting a custom bitclock setting (-B) for the initial flash when using the mkII, but this may not matter. For example:

avrdude -p m32u4 -c avrispmkII -U flash:w:orch_default_production.hex:i -B 154.37

You should now be able to flash regular (non-:production) firmware that doesn't include the bootloader over USB using QMK Tookbox.

Sublicenses

• Thank you to coseyfannitutti for the footprints D_DO-35_SOD27_P5.08mm_Horizontal.kicad_mod and USB_C_GCT_USB4085.kicad_mod. The Creative Commons license for these is included here.
• Thanks to ai03-2725 for the MX* symbols. The MIT license for these is included here.