HardLabs

LoChord

kiwifruit0·LoChord·lochord_hw/lochord_hw.kicad_pcb

LoChord PCB layout, top view — open source board by kiwifruit0

About the LoChord PCB

LoChord is an open source PCB design by kiwifruit0, published on GitHub. It is a 4-layer board measuring 130 × 90 mm, with 76 components from 39 distinct parts.

Other key parts include the WT0132P4-A1-N16R32, AMS1117-3.3, LP5907MFX-3.3, USBLC6-2SC6 and ES8388. By type, the board carries 27 resistors, 26 capacitors, 10 switches, 5 ICs, 5 connectors and 1 transistor.

It belongs with the audio, keyboards and usb & debug tools designs in this gallery.

From the project

An open-source version of the popular midi device: HiChord

A real-time MIDI chord controller for ESP32-P4, with chord generation, looping, and parameter control. Inspired by the HiChord, but not a clone — see CLAUDE.md for how the two differ.

LoChord is both a firmware project and a hardware project developed together in one repo.

- WT0132P4-A1-N16R32 module — ESP32-P4, dual-core RISC-V, 16MB flash, 32MB in-package PSRAM, no radio - 7× Kailh Choc v1 chord switches + 1× loop button, hand-soldered, direct GPIO - 3× ALPS EC11 clickable rotary encoders (1 UI, 2 control) - Nintendo Switch joystick module on a 5-pin FPC - 428×142 2.79" NV3007 TFT LCD…

Main components on the LoChord

WT0132P4-A1-N16R32AMS1117-3.3LP5907MFX-3.3USBLC6-2SC6ES8388

LoChord bill of materials (BOM)

76 components, 39 distinct parts.

QtyPartRefs
1
WT0132P4-A1-N16R32
U1
1
AMS1117-3.3
U2
1
LP5907MFX-3.3
U3
1
USBLC6-2SC6
U4
1
ES8388
U5
1
SI2302
Q1
1
USB-C 16P
J1
1
DEBUG USJ
J2
1
JOYSTICK_NS
J3
1
LCD_ER-TFT2.79-1
J4
1
PJ-320D
J5
1
EN
SW1
1
BOOT
SW2
1
CHORD1
SW3
1
CHORD2
SW4
1
CHORD3
SW5
1
CHORD4
SW6
1
CHORD5
SW7
1
CHORD6
SW8
1
CHORD7
SW9
Show 19 more
QtyPartRefs
1
LOOP
SW10
1
GREEN
D1
1
600R@100MHz
FB1
3
1uF
C1, C7, C8
1
100uF/10V
C2
2
22uF/25V
C3, C5
11
100nF
C4, C6, C10, C11, C13, C14, C16, C18 +3
7
10uF
C9, C12, C15, C17, C19, C21, C22
2
220uF/6.3V
C24, C25
11
10k
R1, R5, R6, R7, R8, R9, R10, R11 +3
2
5.1k
R2, R3
1
470R
R4
1
22R
R14
2
56R
R15, R27
1
100k
R16
1
100R
R17
4
33R
R18, R19, R20, R21
2
4.7k
R22, R23
2
10R
R25, R26

LoChord design files

The KiCad project lives in the kiwifruit0/LoChord repository on GitHub; these links point at the commit this page was built from.

LoChord: common questions

How big is the LoChord PCB?

The LoChord measures 130 × 90 mm, has 4 copper layers and is 1.6 mm thick.

How many components are on the LoChord?

76 components, from 39 distinct parts. The full bill of materials is listed on this page.

Where can I download the LoChord design files?

From the kiwifruit0/LoChord repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the LoChord design in my own project?

The repository has no license, so all rights stay with kiwifruit0. Use it as a reference, and ask the author before reusing the design.

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