MOD2 - RP2350 Digital Percussion Module#

MOD2 is a digital percussion synthesizer built on the powerful RP2350 microcontroller. Generate classic and experimental drum sounds with precise parameter control.

Hardware: RP2350 (Raspberry Pi Pico 2) · Digital Synthesis · 6 Parameters per Voice · Eurorack Format

Firmware Options#

Choose from 7 different synthesis algorithms, plus 2 sample-based firmware from Hagiwo’s Patreon:

Braids#

Macro oscillator with 47 different synthesis engines - from classic waveforms to granular synthesis and physical modeling.

OR 💾 Download Braids Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

Clap#

Digital TR-808-style clap with adjustable tone, decay, and density parameters.

OR 💾 Download Clap Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

Claves#

Sine/triangle wave-based claves with LED envelope visualization and tunable parameters.

OR 💾 Download Claves Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

FM Drum#

Two-operator FM percussion synthesis - create metallic, bell-like, and experimental drum sounds.

OR 💾 Download FM Drum Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

Hi-Hat#

White/blue noise-based hi-hat with tone shaping and envelope control.

OR 💾 Download Hi-Hat Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

Kick Drum#

Sine wave-based kick drum with 6 controllable parameters - pitch, decay, punch, and more.

OR 💾 Download Kick Drum Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

VCO#

Six-waveform voltage controlled oscillator with 1V/Oct tracking and PolyBLEP anti-aliasing.

OR 💾 Download VCO Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

FLUX - Physical Modeling & Noise (7 modes)#

Six-modes from ordered resonance to pure chaos + addition Drone mode

OR 💾 Download FLUX Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

SPIRAL FOREVER - Auditory Illusions#

Different Shepard tones, Euler Spiral, Tritone Paradox, etc.

OR 💾 Download SPIRAL Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

Tides (WIP)#

Mutable Instruments Tides port - function generator and wavetable oscillator. Multiple output modes (amplitudes, phases, frequencies, gates) and ramp modes (looping LFO, AD envelope, AR envelope).

OR 💾 Download Tides Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

Sample-Based Firmware (Patreon Exclusive)#

The following firmware require pre-compiled sample data and are available from Hagiwo’s Patreon:

Break Beats#

The legendary “Amen Break” and “Think Break” samples - two of the most iconic drum breaks in music history.

PATREON EXCLUSIVE

Classic break beats featuring the Amen Break and Think Break samples.

This firmware requires pre-compiled sample data that is not included in the open-source repository.

Support the creator and get this firmware from Hagiwo's Patreon!

Get Break Beats from Patreon (Opens Hagiwo's Patreon)
💖 Support Hagiwo: By downloading from Patreon, you support the continued development of MOD2 firmware and hardware.

Sample Player#

18-slot customizable sample player with variable playback speed and high-quality audio.

PATREON EXCLUSIVE

Customizable sample player with 18 slots for your own audio samples.

This firmware requires pre-compiled sample data that is not included in the open-source repository.

Support the creator and get this firmware from Hagiwo's Patreon!

Get Sample Player from Patreon (Opens Hagiwo's Patreon)
💖 Support Hagiwo: By downloading from Patreon, you support the continued development of MOD2 firmware and hardware.

Square Wave VCO#

Square wave oscillator (with V/oct support), LFO for vibrato, octave toggling and chiptune.

OR 💾 Download Square VCO Firmware Manual flashing (.uf2 file)
📋 Flashing Instructions

Web Flashing (Recommended):

  1. Click "One-Click Flash" button above
  2. Select your XIAO RP2350 from the serial port list
  3. Wait ~5 seconds for the RPI-RP2 drive to appear
  4. Click the orange button and select the RPI-RP2 drive
  5. Firmware flashes automatically!

Manual Flashing:

  1. Disconnect Eurorack power before connecting USB
  2. Hold BOOTSEL button while connecting USB
  3. Device appears as RPI-RP2 USB drive
  4. Download firmware and copy to RPI-RP2 drive
  5. Module will automatically reboot
⚠️ Safety: Always disconnect eurorack power before connecting USB!

Features#

  • RP2350 Processor: 150 MHz dual-core ARM Cortex-M33
  • High-Quality Audio: ~36.6 kHz sample rate, 10-bit PWM output
  • Parameter Storage: Settings saved to flash memory
  • Real-Time Control: 6 potentiometers for immediate sound shaping
  • Trigger Input: Gate/trigger responsive
  • CV Inputs: Modulate parameters with external CV
  • LED Feedback: Visual indication of envelope and parameters

Technical Specifications#

  • Sample Rate: 36.6 kHz (150 MHz / 4096)
  • Resolution: 10-bit (1024 levels)
  • EEPROM: 128 bytes flash-based parameter storage
  • Power: Eurorack +12V / -12V
  • Upload: USB drag-and-drop (.uf2 format)

Hardware Requirements#

  • RP2350-based Module (Raspberry Pi Pico 2 or compatible)
  • MOD2 Eurorack hardware
  • USB cable for firmware updates
  • Important: Disconnect eurorack power before USB connection

About RP2350 Firmware Updates#

The RP2350 uses a simple drag-and-drop method for firmware updates:

  1. No bootloader selection needed - RP2350 handles everything
  2. Device appears as a USB drive when in BOOTSEL mode
  3. Simply drag the .uf2 file to the drive
  4. Automatic reboot with new firmware

No Arduino IDE required - pre-compiled .uf2 files ready to use!

Resources#

Next-generation digital percussion synthesis for Eurorack