

Larva v3
larva keyboard related sketches, materials, etc
- Size
- 228 × 82.1 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 98
- Nets
- 90
- Pads
- 453
- Tracks, vias
- 1,082, 73
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 20 Feb 2021
- Updated
- 5 May 2024
Overview
Larva v3 is an open-source printed circuit board by grezeh, from the grezeh/larva repository on GitHub, published under the MIT licence. It is a 2-layer board of 228 × 82.1 mm with 98 parts on 90 nets, routed with 1,082 tracks and 73 vias.
It is built around the ATMEGA32U4-MU, USBLC6-2SC6 and BAT54C. Its parts include 22 diodes, 12 resistors, 8 capacitors, 2 ICs and 2 connectors. It belongs with the keyboards and input boards and the AVR (ATmega, ATtiny) boards of this library.
Main components
3ATMEGA32U4-MU
VQFN-44-EP(7x7)-40℃~+85℃ 10bit 16MHz 1KB 2.5KB 2.7V~5.5V 26 32KB 8 Bit AVR Built-in FLASH VQFN-44-EP(7x7) Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)USBLC6-2SC6
SOT-23-60.35pF、0.8pF 100nA 150W@8/20us 15V 2 5V 6A@8/20us 6V ESD SOT-23-6 ESD and Surge Protection (TVS/ESD) ROHSUMWESD And Surge Protection (TVS/ESD)BAT54C
SOT-231 Pair Common Cathode 200mA 2uA@25V 30V 600mA 800mV@100mA SOT-23 Schottky Diodes ROHSNexperiaSchottky Diodes
README
README.mdlarva
larva keyboard related sketches, materials, etc
larva mk.2

Mk.3 options:

Larva keyboard is designed as part of a personal platform for research of combined, adaptable, extended latin+cyrillic keymap and layout with better ergonomics for day-to-day use.
Keyboards, keymap, layouts are developed concurrently, work in symbiosis. I name the whole research project "mnemoNИk|Kombine".
Larva PCB+custom plate fits in "daisy40% hhkb" keyboard case by Kprepublic. Larva mk1 has 4 through-hole LED positions, no rgb, uses *AU mcu.
Mk2 has in addition 2 rgb smd LED slots for up-facing SK6812MINI-E LEDs and 2 pre-assembled mono-color smd LEDs as alternative to 2 lower through-hole LEDs(facedown, was an experimental feature) and a few small QoL improvements.
Mk2.1-light version cuts rgb and goes open-source. Pcbs routed by MarvFPV
Mk.3 pcb outline made smaller, to additionally fit "poseidon40" case by kprepublic. Added one more bottom row option and total-non-stab option (without iso enter). Modded by JLW, according to my specs (will see after the proto-run, how were the assumptions).
Current software-side implementation consists of QMK/vial +custom Windows keymap (needs updating).
Default keymap is basic latin+ numpad keycodes (looks chaotic, but gives more possibilities to reprogam); top-mid led is programmed as Num.Lock and it's engaged (put your novelties there and light them up; engaged numlock enables better bottom row options).
For activating the bootloader: press the RST button on the back of the pcb.
(The keyboard design line is constantly evolving, can differ in shapes and sizes, but all serve the same ultimate goal. Current line consists of: Larva mk1\mk2\mk2.1\mk3; Katerpillar; Katerpillar Infiltrator; Wodka; Wolof; Dragonfly; Butterfly; Mothra; Stargate; Galaga mk.1\mk.2\mk.3; Boardstroll)
- Keyboard Maintainer: grezeh
- Hardware Supported: Larva mk.2 pcb (atmega32u4)
- Hardware Availability: discord, occasionally, maybe
QMK hex file compilation for this keyboard (after setting up your build environment,in QMK SYS for Qmk Toolbox):
qmk compile -kb grezeh/larva/larva2 -km default (compiles locally, needs to go upstream at one point)VIAL hex file compilation:
qmk compile -kb grezeh/larva/larva2 -km vial (compiles locally. from vial git repo- not with recent changes; need to investigate, what new they implemented)See the build environment setup and the make instructions for more information. Brand new to QMK? Start with our Complete Newbs Guide.
ps: lately vial have been giving errors, but locally still compiles fine. needs investigating (also, rgb is borked in current version- was experimental feature anyway, cut in version 2.1-light)
oktoberfest'22- open sause the thing!
(now need to make "house in order", so noone brakes legs here. will upload simplified keymap later. Basically: need to upload qmk and vial files here, in addition to keymap)
feedback on possible schematics flaws/improvements is appreciated
Parts
98| Qty | Value | Footprint | References |
|---|---|---|---|
| 28 | MX-NoLED | MxSwitches:MXOnly-1U-NoLED | MX2, MX10, MX12, MX13, MX14, MX15, MX17, MX18, MX19, MX20, MX22, MX23, MX24, MX25, MX26, MX29 +12 |
| 21 | BAT54C | Package_TO_SOT_SMD:SOT-23 | D1, D2, D3, D4, D10, D11, D12, D13, D14, D15, D16, D17, D19, D20, D21, D22 +5 |
| 7 | MX-NoLED | MxSwitches:MXOnly-1.25U-NoLED | MX11, MX35, MX36, MX37, MX38, MX39, MX40 |
| 3 | 0.1uF | Capacitor_SMD:C_0603_1608Metric | C1, C2, C3 |
| 3 | MX-NoLED | PCM_marbastlib-mx:SW_MX_1.5u | MX43, MX45, MX46 |
| 2 | 10k | Resistor_SMD:R_0603_1608Metric | R1, R11 |
| 2 | 22 | Resistor_SMD:R_0603_1608Metric | R2, R3 |
| 2 | 22pF | Capacitor_SMD:C_0603_1608Metric | C7, C8 |
| 2 | 5.1k | Resistor_SMD:R_0603_1608Metric | R4, R5 |
| 2 | 680 | Resistor_SMD:R_0603_1608Metric | R7, R8 |
| 2 | 680 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R12, R13 |
| 2 | MX-LED | PCM_marbastlib-mx:SW_MX_1u | MX27, MX28 |
| 2 | MX-NoLED | PCM_marbastlib-mx:SW_MX_1u | MX44, MX47 |
| 1 | 100nF | Capacitor_SMD:C_0603_1608Metric | C6 |
| 1 | 10uF | Capacitor_SMD:C_0603_1608Metric | C4 |
| 1 | 1M | Resistor_SMD:R_0603_1608Metric | R10 |
| 1 | 1uF | Capacitor_SMD:C_0603_1608Metric | C5 |
| 1 | 300 | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R14 |
| 1 | 500mA | Fuse:Fuse_1206_3216Metric | F1 |
| 1 | ATmega32U4-M | Package_DFN_QFN:QFN-44-1EP_7x7mm_P0.5mm_EP5.2x5.2mm | U1 |
| 1 | Conn_02x03_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical | J1 |
| 1 | Crystal_GND24_Small | Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm | Y1 |
| 1 | LED | LED_SMD:LED_0805_2012Metric | D24 |
| 1 | MX-LED | MxSwitches:MXOnly-1U | MX6 |
| 1 | MX-LED | MxSwitches:MXOnly-1.5U | MX16 |
| 1 | MX-NoLED | MxSwitches:MXOnly-ISO-ROTATED-ReversedStabilizers-NoLED | MX21 |
| 1 | MX-NoLED | PCM_marbastlib-mx:SW_MX_1.25u | MX42 |
| 1 | MX-NoLED | MxSwitches:MXOnly-1.5U-NoLED | MX1 |
| 1 | MountingHole | LarvaLogo:larvasidelines | H2 |
| 1 | MountingHole | LarvaLogo:larvalogo3 | H1 |
| 1 | SW_Push | KeebParts:SKQG-1155865 | SW1 |
| 1 | USBLC6-2SC6 | Package_TO_SOT_SMD:SOT-23-6 | U2 |
| 1 | USB_C_Receptacle_USB2.0 | Connector_USB:USB_C_Receptacle_HRO_TYPE-C-31-M-12 | J2 |
Questions
How big is the Larva v3 PCB?
It measures 228 × 82.1 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Larva v3 use?
98 parts, built around the ATMEGA32U4-MU, USBLC6-2SC6 and BAT54C. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Larva v3 KiCad files?
From the grezeh/larva repository on GitHub, at the commit this page was made from: the board is v3/Larva v3.kicad_pcb and its schematic Larva 2.1-light/Larva.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Larva v3 design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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