Seed3 Pedal Dev Kit

An Effects Pedal Platform for the Daisy Seed3

The Seed3 Pedal Dev Kit provides everything you need to design and prototype your next Daisy-based effects pedal on a single, purpose-built board. Create powerful DSP effects — massive reverbs, delay networks, complex loopers, spectral processors, and granular engines the likes of which have yet to grace the pedal world.

With industry-standard components and circuitry onboard, moving a Daisy design into production has never been easier. On top of stereo I/O and a host of electromechanical controls, the Dev Kit includes DIN MIDI I/O, a TRS expression input, a microSD socket, and a USB-C port. Take your DSP pedals to the next level with Daisy.

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Contents

• Features
• Specifications
• Getting Started
• Making Your Own Project
• Hardware Reference
• Resources & Support
• Open-Source Hardware
• License

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Features

Category	Details
Audio	Stereo audio input and output
MIDI	DIN MIDI In, Out, and Thru
Expression	TRS expression pedal input
USB	USB-C port connected to the Seed3's external USB peripheral, for USB features in your firmware
Storage	microSD slot for firmware updates, samples, presets, configuration, and more
Potentiometers	6 × 10kΩ linear (B-taper)
Footswitches	2 × footswitches
Buttons	2 × tactile switches
Toggle Switches	3 × toggle switches (1 × ON-OFF-ON, 2 × ON-ON)
LEDs	1 × RGB LED, 1 × red LED
Power	9V DC barrel jack, center negative (standard pedal supply)

Specifications

Parameter	Value
Processor module	Daisy Seed3
Supply voltage	9V DC, center negative
Current draw	Firmware dependent
Reverse polarity protection	Yes
Audio codec / sample rate	TAC5242 / up to 32-bit, 192kHz
Input impedance	1MΩ
Output impedance	100Ω
Board dimensions	197mm × 100mm
Expression input	TRS
MIDI connectors	3 × 5-pin DIN (In, Out, Thru)

Warning

Use a center-negative 9V DC supply.

Getting Started

1. Install the toolchain

Follow the Daisy C++ Getting Started guide. It installs the toolchain and clones DaisyExamples, which includes libDaisy (hardware library) and DaisySP (DSP library).

2. Update libDaisy

The Pedal Dev Kit template and board support are newer than the copy of libDaisy included with DaisyExamples. From your DaisyExamples folder, update libDaisy to its latest version, fetch its own dependencies, and rebuild it:

git submodule update --remote libDaisy
git -C libDaisy submodule update --init --recursive
make -C libDaisy

The first line moves libDaisy to its latest version. The second fetches libDaisy's own dependencies, such as the STM32 drivers it needs to compile. The last line rebuilds libDaisy, which is required after any update.

Caution

Running git submodule update --init --recursive or git pull --recurse-submodules from the DaisyExamples folder afterwards resets libDaisy to the older version DaisyExamples was built with. If that happens, run the three commands above again.

3. Build the template

The starting project for this kit is examples/devkits/Pedal-DevKit-Template. From the libDaisy folder:

cd examples/devkits/Pedal-DevKit-Template
make

This creates Pedal-DevKit-Template.bin in the template's build/ folder.

4. Flash the Seed3

Important

Program the Seed3 through the USB-C port on the Seed3 module itself, not the USB-C port on the Dev Kit board.

1. Connect a USB-C cable from your computer to the Seed3's USB-C port.

2. Hold BOOT, press and release RESET, then release BOOT.

3. From the template folder, run:

   make program-dfu

   Or, in the Daisy Web Programmer, upload the Pedal-DevKit-Template.bin file from the build/ folder.

5. Power up and try it out

Connect a 9V center-negative supply to the barrel jack (J8) and plug in your instrument and amp. You can leave the Seed3's USB cable connected so you can watch the serial output.

Tip

If you are experiencing USB noise from keeping the Seed3 connected to the computer, disconnect during testing.

The template:

• Passes audio from the inputs straight to the outputs.
• Blinks the red LED (LED1) and cycles the colors of the RGB LED (LED2).
• Echoes MIDI notes received on MIDI In to MIDI Out.
• Prints the state of every control over USB serial on the Seed3's USB-C port. Open any serial monitor to see it.

Making Your Own Project

Edits only take effect on the pedal after you rebuild and reflash, so start your own project from a copy of the template.

1. Copy the Pedal-DevKit-Template folder into your DaisyExamples folder and rename it, for example DaisyExamples/MyPedal.

2. In the copied Makefile:

   • Set TARGET to your project name, for example TARGET = MyPedal.
   • Change LIBDAISY_DIR to point to libDaisy from the new location: LIBDAISY_DIR = ../libDaisy.
   • To use DaisySP, uncomment the DaisySP line and set DAISYSP_DIR = ../DaisySP.

3. Write your effect in src/main.cpp. Audio is processed in AudioCallback(): inputs are in[0][i] (left) and in[1][i] (right), and outputs are out[0][i] and out[1][i] (see Audio).

4. Rebuild and flash after every change:

   make
   make program-dfu

   Put the Seed3 into BOOT mode (step 4 above) before each make program-dfu.

Tip

The template builds with debugging enabled (DEBUG = 1, OPT = -Og). For release builds, set DEBUG = 0 and OPT = -O3 in the Makefile. If your program grows too large for the Seed3's internal flash, see the Daisy Bootloader guide.

Hardware Reference

The Ref column lists each part's reference designator, as printed on the board's silkscreen.

Pinout

A printable Pinout PDF is also available.

Audio

Jack	Ref	Silkscreen	Signal	Audio Callback
Input Left	J2	IN LEFT	AUDIO_IN_L	in[0][i]
Input Right	J4	IN RIGHT	AUDIO_IN_R	in[1][i]
Output Left	J3	OUT LEFT	AUDIO_OUT_L	out[0][i]
Output Right	J5	OUT RIGHT	AUDIO_OUT_R	out[1][i]

Controls

Control	Ref	Signal	Seed3 Pin	Notes
Potentiometer 1	VR1	POT_1	D15	10kΩ B-taper
Potentiometer 2	VR2	POT_2	D16	10kΩ B-taper
Potentiometer 3	VR3	POT_3	D17	10kΩ B-taper
Potentiometer 4	VR4	POT_4	D18	10kΩ B-taper
Potentiometer 5	VR5	POT_5	D19	10kΩ B-taper
Potentiometer 6	VR6	POT_6	D20	10kΩ B-taper
Expression input	J6	ADC_EXPRESSION	D21	TRS
Footswitch 1	FSW_1	GPIO_FSW_1	D10
Footswitch 2	FSW_2	GPIO_FSW_2	D23
Tactile switch 1	SW3	TAC_SW1	D0
Tactile switch 2	SW4	TAC_SW2	D28
Toggle switch 1	SW1	TOG_2_A / TOG_2_B	D8 / D7	ON-OFF-ON (3-position, two pins)
Toggle switch 2	SW2	TOG_1	D9	ON-ON
Toggle switch 3	SW6	TOG_3	D22	ON-ON

LEDs

LED	Ref	Signal	Seed3 Pin
Red LED	LED1	LED_MONO_1	D24
RGB LED — Red	LED2	LED_R	D25
RGB LED — Green	LED2	LED_G	D27
RGB LED — Blue	LED2	LED_B	D26

MIDI

Jack	Ref	Signal	Seed3 Pin	Direction
MIDI Out	J11	MIDI_TX	D13	Out
MIDI In	J10	MIDI_RX	D14	In
MIDI Thru	J1	MIDI_RX	D14	Mirrors MIDI In

microSD (SDMMC, 4-bit)

Signal	Seed3 Pin
SDMMC_CK	D6
SDMMC_CMD	D5
SDMMC_D0	D4
SDMMC_D1	D3
SDMMC_D2	D2
SDMMC_D3	D1

USB-C

The Dev Kit's USB-C port connects to the Seed3's external USB peripheral. It is separate from the USB-C port on the Seed3 module, which is used for programming and for the template's serial output.

Signal	Seed3 Pin
USB_OTG_HS_N	D29
USB_OTG_HS_P	D30

Power

Connector	Ref	Notes
DC barrel jack	J8	9V DC, center negative

Resources & Support

• Product Page: Seed3 Pedal Dev Kit
• Documentation: docs.daisy.audio
• Community Forum: community.daisy.audio
• Discord: Daisy Discord
• Issues: Report bugs or hardware errata via this repository's Issues tab.

Design Files

• Schematic (PDF)
• Bill of Materials (CSV)
• Pinout (PDF)
• KiCad Design Files

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Open-Source Hardware

The Pedal Dev Kit is open-source hardware, built to the Open Source Hardware Definition published by the Open Source Hardware Association (OSHWA). The schematics, PCB layouts, bill of materials, and KiCad source files are published so that you can study, modify, manufacture, and sell your own designs based on them.

License

Copyright © 2026 Qu-Bit Electronix, Inc. (dba Daisy)

The hardware design files in this repository are licensed under the CERN Open Hardware Licence Version 2 – Permissive (CERN-OHL-P-2.0).

Subject to the terms of that licence, you may:

• Use, study, copy, modify, and distribute these designs and any products made from them.
• Incorporate these designs, in whole or in part, into closed-source and commercial products.

These designs are provided "as is", without warranty of any kind, express or implied. See LICENSE for the full licence text, including the disclaimer of warranty and limitation of liability.

Firmware and software, including libDaisy and DaisySP, are licensed separately under the terms included in their respective repositories.

SPDX-License-Identifier: CERN-OHL-P-2.0

Trademarks

DAISY® is a trademark of Qu-Bit Electronix, Inc., registered in the United States. CERN-OHL-P-2.0 grants a license to the copyright and related rights in these designs. It does not grant any right or license to use the DAISY name, logos, product names, or other trademarks of Qu-Bit Electronix, Inc.

Products, derivative designs, and related materials made from these designs may not:

• Use the DAISY name or logo, or any confusingly similar name or mark, in a product name, model number, brand, domain name, or marketing material.
• Reproduce the DAISY name or logo on a PCB silkscreen, front panel, enclosure, packaging, or documentation, except where needed to keep the required licence notices.
• State or imply that the product is made, endorsed, sponsored, certified, or supported by Qu-Bit Electronix, Inc.

You may make truthful, factual statements about compatibility or origin, such as "based on the Seed3 Pedal Dev Kit design" or "compatible with the Daisy Seed3", provided the statement does not suggest affiliation or endorsement. If you redistribute or sell products derived from these designs, remove the DAISY name and logo from the silkscreen and other artwork before manufacture.

For trademark licensing or permission requests, contact Qu-Bit Electronix, Inc. through daisy.audio/pages/support.