HardLabs

Lo-Key

chgray·LG-Yeet-Keyboard

Lo-Key PCB layout, top view — open source AVR/Arduino board by chgray

About the Lo-Key PCB

Lo-Key is an open source AVR/Arduino PCB design by chgray, published on GitHub. It is a 2-layer board measuring 358.3 × 123.4 mm, with 401 components from 107 distinct parts.

Its main chip is the ATmega32U4-MU, from the AVR/Arduino family. By type, the board carries 192 diodes, 106 capacitors, 79 switches, 4 resistors, 2 connectors and 1 IC.

It belongs with the keyboards designs in this gallery.

From the project

Dropping Areay for custom keyboard

https://github.com/freerouting/freerouting

https://caniusevia.com/docs/specification/

qmk c2json -km default -kb handwired/ckey -o foo.json ./keyboards/handwired/ckey/keymaps/default/keymap.c

- to make the BOM load eeschema and then do the button ("generate bill of material") BOM -> bom2csv you're looking for chgray-keyboard.csv A) Change Reference to "Designator" B) Change Datasheet to "JLCPCB Part #" C) Value to Comment

Main components on the Lo-Key

ATmega32U4-MU

Lo-Key bill of materials (BOM)

401 components, 107 distinct parts.

QtyPartRefs
1
ATmega32U4-MU
U1
1
Crystal
Y1
1
Conn_01x07_Female
J1
1
USB_B_Mini
J2
1
59
Backspace1
1
20
CAPS1
1
011
ENTER1
1
31
LEFT-SHIFT1
1
44
LEFT-SPACE1
1
43
LEFT_ALT1
1
40
LEFT_CTRL1
1
41
LEFT_FN1
1
55
RIGHT-SHIFT1
1
65
RIGHT-SHIFT2
1
47
RIGHT-SPACE1
1
311
RightMeta1
1
012
S1
1
013
S2
1
30
SW1
1
50
SW2
Show 87 more
QtyPartRefs
1
60
SW3
1
00
SW4
1
01
SW5
1
11
SW6
1
21
SW7
1
51
SW8
1
61
SW9
1
22
SW10
1
32
SW11
1
52
SW12
1
62
SW13
1
02
SW14
1
12
SW15
1
03
SW16
1
13
SW17
1
23
SW18
1
33
SW19
1
53
SW20
1
63
SW21
1
24
SW22
1
34
SW23
1
54
SW24
1
64
SW25
1
04
SW26
1
14
SW27
1
05
SW28
1
15
SW29
1
25
SW30
1
35
SW31
1
45
SW32
1
26
SW33
1
36
SW34
1
46
SW35
1
56
SW36
1
66
SW37
1
06
SW38
1
16
SW39
1
07
SW40
1
17
SW41
1
27
SW42
1
37
SW43
1
57
SW44
1
67
SW45
1
28
SW46
1
38
SW47
1
48
SW48
1
58
SW49
1
68
SW50
1
08
SW51
1
18
SW52
1
09
SW53
1
19
SW54
1
29
SW55
1
39
SW56
1
49
SW57
1
69
SW58
1
010
SW59
1
110
SW60
1
210
SW61
1
310
SW62
1
410
SW63
1
510
SW64
1
211
SW65
1
411
SW66
2
511
SW67, SW77
1
112
SW68
1
212
SW69
1
312
SW70
1
412
SW71
1
512
SW72
1
113
SW73
1
213
SW74
1
313
SW75
1
413
SW76
1
SW_Push
SW_RESET1
1
111
Slash1
1
10
TAB1
1
42
WinKey1
94
DIODE
D1, D2, D3, D4, D5, D6, D7, D8 +86
98
LED
D95, D96, D97, D98, D99, D100, D101, D102 +90
98
C104 0.1uF 100nF
C1, C2, C3, C4, C5, C6, C7, C8 +90
4
0.1u
C102, C103, C104, C105
1
10u
C106
2
22p
C107, C108
1
1u
C109
2
R10k
R1, R4
2
22R
R2, R3

Lo-Key design files

The KiCad project lives in the chgray/LG-Yeet-Keyboard repository on GitHub; these links point at the commit this page was built from.

Lo-Key: common questions

What microcontroller does the Lo-Key use?

The Lo-Key is built around the ATmega32U4-MU, from the AVR/Arduino family.

How big is the Lo-Key PCB?

The Lo-Key measures 358.3 × 123.4 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Lo-Key?

401 components, from 107 distinct parts. The full bill of materials is listed on this page.

Where can I download the Lo-Key design files?

From the chgray/LG-Yeet-Keyboard repository on GitHub, which has the KiCad layout; the links under Design files point to each one.

Can I use the Lo-Key design in my own project?

The repository has no license, so all rights stay with chgray. Use it as a reference, and ask the author before reusing the design.

Can I test firmware for the Lo-Key without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug AVR/Arduino firmware against it before you order a PCB.

Similar boards