6 layers160 × 100 mm
4 layers119 × 63.2 mm
OpenChordM1
FugLong/OpenChord3An open-source music device for portable, expressive, and extensible audio creation.
- Size
- 119 × 63.2 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 75
- Nets
- 124
- Pads
- 476
- Tracks, vias
- 696, 120
- Pours
- 6
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 30 Jul 2025
- Updated
- 8 Oct 2026
Overview
OpenChordM1 is an open-source printed circuit board by FugLong, from the FugLong/OpenChord repository on GitHub, published under the MIT licence. It is a 4-layer board of 119 × 63.2 mm with 75 parts on 124 nets, routed with 696 tracks and 120 vias.
It is built around the RP2040, IQS572-BL-QNR and W25Q32JVSSIQ, with the AP2112K-3.3TRG1, TLP2361(E and USBLC6-2SC6 among its other parts. Its parts include 30 resistors, 14 capacitors, 12 switches, 9 ICs and 3 connectors. It belongs with the audio and music boards and the RP2040 boards of this library.
Main components
12
RP2040
LQFN-56(7x7)12bit 133MHz 30 LQFN-56(7x7) Microcontrollers (MCU/MPU/SOC) ROHSRaspberry PiMicrocontrollers (MCU/MPU/SOC)
IQS572-BL-QNR
QFN-28(4x4)-40℃~+85℃ 1.65V~3.6V 72 Capacitive Touch、Automatic sensitivity calibration、Proximity detection、Gesture detection、Sliding touch QFN-28(4x4) Touch Sensors ROHSAzoteqTouch Sensors
W25Q32JVSSIQ
SOIC-8-208mil-40℃~+85℃ 100,000 cycles 133MHz 1uA 2.7V~3.6V 20 Years 32Mbit 3ms SPI SOIC-8-208mil NOR FLASH ROHSWinbondNOR FLASH
AP2112K-3.3TRG1
SOT-25-5-40℃~+85℃@(Ta) 1 250mV@(600mA) 3.3V 50uVrms 55uA 600mA 65dB@(1kHz) 6V Fixed Over Current Protection、Thermal Shutdown、Enable control Positive SOT-25-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSDiodes IncorporatedVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
TLP2361(E
SO-6,5LEAD-40℃~+125℃ 1.5V 1.6mA 10mA 15Mbps 2.7V~5.5V 20kV/us 3.75kV 5V 6V 6mA 80ns 80ns DC SO-6,5LEAD Logic Output Optoisolators ROHSToshibaLogic Output Optoisolators
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)
CC0603KRX7R9BB104
0603100nF 50V X7R ±10% 0603 Multilayer Ceramic Capacitors MLCC - SMD/SMT ROHSYAGEOMultilayer Ceramic Capacitors MLCC - SMD/SMT
RC0603FR-0710KL
UncategorisedUnknown makerCC0603KRX5R8BB105
06031uF 25V X5R ±10% 0603 Multilayer Ceramic Capacitors MLCC - SMD/SMT ROHSYAGEOMultilayer Ceramic Capacitors MLCC - SMD/SMT
EVQPUC02K
SMD,4.7x4.5mm-20℃~+70℃ 1.65mm 100,000 cycles 12V 2.2N 4.5mm 4.7mm 50mA PC Pin Rectangular Button SPST Surface Mount, Right Angle SMD,4.7x4.5mm Tactile Switches ROHSPanasonicTactile Switches
CL21A106KOQNNNE
080510uF 16V X5R ±10% 0805 Multilayer Ceramic Capacitors MLCC - SMD/SMT ROHSSamsung Electro-MechanicsMultilayer Ceramic Capacitors MLCC - SMD/SMT
1N4148WS
SOD-3231.25V@150mA 100V 150mA 1uA@75V 200mW 2A 4ns Independent SOD-323 Switching Diodes ROHSJiangsu Changjing Electronics Technology (CJ)Switching Diodes
README
README.mdOpenChord
A family of open hardware instruments for harmony and music-making. MIT licensed. OpenChord M Core (plugin) is free; the OpenChord M1 box is what we sell.
M-series is MIDI. S-series is studio. Numbers are generations.
| Product | What it is | Status |
|---|---|---|
| OpenChord M1 | MIDI-only chord brain. RP2040 hardware under $100, plus free OpenChord M Core (AU/VST3, same engine). | Active — engine / proto / plugin v0 |
| OpenChord S1 | Studio / portable jambox: synth, tracks, the original dream device. | Later |
| M2 / S2 | Next generations of each line. | Not started |
OPENCHORD OPENCHORD
m1 s1Repo layout
m1/ M1 engine, firmware, plugin, hardware, docs (start here)
s1/ Reserved for the jambox when it is real
archive/s1-daisy/ Frozen Daisy Seed prototype (do not treat as S1)
LICENSE MITThe Daisy Seed project that used to live at the repo root is intact under archive/s1-daisy/. It is a prototype archive, not the S1 codebase.
Start with M1
Read m1/docs/goals.md for the product plan (hardware + free plugin). Hands-on testing is m1/proto-rp2040 (RP2040-Zero USB MIDI, Pro mode). Plugin: m1/plugin (OpenChord M Core, Pro + Smart). The archived Seed box is parked. Do not edit the archive.
License
MIT — see LICENSE.
Parts
75| Qty | Value | Footprint | References |
|---|---|---|---|
| 16 | 1k | Resistor_SMD:R_0603_1608Metric | R5, R7, R16, R17, R18, R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29 |
| 8 | SW_Gateron_LP | oc-gateron:Gateron-KS33-Hotswap-1U | SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8 |
| 6 | 100nF | Capacitor_SMD:C_0603_1608Metric | C1, C3, C4, C5, C6, C14 |
| 5 | 10k | Resistor_SMD:R_0603_1608Metric | R6, R13, R14, R15, R30 |
| 4 | 1uF | Capacitor_SMD:C_0603_1608Metric | C2, C7, C8, C9 |
| 4 | TestPoint | TestPoint:TestPoint_Pad_D1.5mm | TP-GND1, TP-SWCLK1, TP-SWDIO1, TP-VBUS1 |
| 3 | EVQPUC02K | oc-btn:EVQPUC02K | SW9, SW10, SW11 |
| 2 | 10uF | Capacitor_SMD:C_0805_2012Metric | C10, C11 |
| 2 | 15pF | Capacitor_SMD:C_0603_1608Metric | C12, C13 |
| 2 | 22R | Resistor_SMD:R_0603_1608Metric | R3, R4 |
| 2 | 4.7k | Resistor_SMD:R_0603_1608Metric | R8, R9 |
| 2 | 5.1k | Resistor_SMD:R_0603_1608Metric | R1, R2 |
| 1 | 10 | Resistor_SMD:R_0603_1608Metric | R11 |
| 1 | 1N4148WS | Diode_SMD:D_SOD-323 | D1 |
| 1 | 220 | Resistor_SMD:R_0603_1608Metric | R10 |
| 1 | 33 | Resistor_SMD:R_0603_1608Metric | R12 |
| 1 | ABM8-272-T3 | Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm | Y1 |
| 1 | AP2112K-3.3TRG1 | Package_TO_SOT_SMD:SOT-23-5 | U7 |
| 1 | AT42QT2120-XUR | oc-touch:TSSOP-20_L6.5-W4.4-P0.65-LS6.4-BL | U4 |
| 1 | CT_Slider_Chev_3_74d5_15_noESD | captouch:CT_Slider_Chev_3_74d5_15_noESD | U2 |
| 1 | CT_Trackpad_7x7_37D75 | captouch:CT_Trackpad_7x7_37D75 | U5 |
| 1 | IQS572-BL-QNR | oc-touch:QFN-28_L4.0-W4.0-P0.50-TL | U3 |
| 1 | RP2040 | Package_DFN_QFN:QFN-56-1EP_7x7mm_P0.4mm_EP3.2x3.2mm | U1 |
| 1 | SJ1-3523N (IN) | oc-trs:SJ1-3523N | J3 |
| 1 | SJ1-3523N (OUT) | oc-trs:SJ1-3523N | J2 |
| 1 | SSD1306_0.91_4pin | oc-oled:SSD1306-0.91-OLED-4pin-128x32 | DS1 |
| 1 | TLP2361 | oc-midi:TLP2361 | U9 |
| 1 | TS-1187A-B-A-B | oc-btn:TS-1187A-B-A-B | SW13 |
| 1 | TYPE-C-31-M-12 | oc-usb:TYPE-C-31-M-12 | J1 |
| 1 | USBLC6-2SC6 | Package_TO_SOT_SMD:SOT-23-6 | U8 |
| 1 | W25Q32JVSSIQ | Package_SO:SOIC-8_5.3x5.3mm_P1.27mm | U6 |
Questions
How big is the OpenChordM1 PCB?
It measures 119 × 63.2 mm and has 4 copper layers, 1.6 mm thick.
What parts does the OpenChordM1 use?
75 parts, built around the RP2040, IQS572-BL-QNR, W25Q32JVSSIQ and AP2112K-3.3TRG1. 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 OpenChordM1 KiCad files?
From the FugLong/OpenChord repository on GitHub, at the commit this page was made from: the board is m1/hardware/OpenChordM1/OpenChordM1.kicad_pcb and its schematic m1/hardware/OpenChordM1/OpenChordM1.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the OpenChordM1 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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