OSCAR — Open Source Custom Audio Rig

OSCAR is an open-source hardware and software framework designed to provide a solid foundation for developing digital guitar-effect pedals.
The goal of the project is to simplify and speed up the creation of audio effects by offering all the essential building blocks: audio codec management, hardware interfaces (QSPI, SDRAM, GPIO, encoders, footswitch), audio pipeline, parameters, embedded UI, and a modular software architecture ready to use.

Designed as a flexible and scalable platform, OSCAR allows developers to focus directly on creating effects (delay, chorus, tremolo, etc.) instead of dealing with low-level infrastructure. It provides a complete, reusable, and extensible base for quickly building professional-quality digital effect pedals.

Follow all the latest updates, project progress, and demos on my Facebook page! 🎛️🎶

📥 Cloning the Repository

OSCAR uses submodules for hardware and software components.
To clone the complete project with all dependencies:

git clone --recurse-submodules https://github.com/DADDesign-Projects/OSCAR_P01A01

🔧 Specifications — Version P01A01

🧠 Processor Board

OSCAR is built around the “PROC_01” processor board, described in the GitHub repository:
https://github.com/DADDesign-Projects/OSCAR_PROC_01

• Microcontroller STM32H743:
  • High-performance ARM Cortex-M7 MCU, 480 MHz frequency, 2MB Flash memory, 1MB RAM
• Flash Memory 2* W25Q128
  • 32 Moctet, Double mode 8 bits SPI, 120 Mhz
• SDRAM Memory IS42S16320
  • 64 Moctet, 200 Mhz
• USB OTG FS
  • CDC Virtual port COM
  • UDP DownLoad Firmware Update
  • MIDI / USB
• UI
  • 4 Encoders
  • 2 Switchs
  • TFT
    • 2.4 inch, SPI inteface
• MIDI
  • UART TRS Midi in
  • USB MIDI
• Programming/Debugging
  • STLink serial port
  • USB UDP protocol.

🎚 Audio Board

The “AUDIO_01” audio board is documented in the following repository:
https://github.com/DADDesign-Projects/OSCAR_AUDIO_01

• Audio Codec
  • PCM3060: 24-bit stereo audio codec
  • Sampling Rate: 48 kHz
• Analog Dry Channel
  • PGA2310: Stereo volume controller
  • Analog dry path for unaffected signal
• Power Supply
  • Isolated Power: Separate analog and digital domains
  • Input Voltage: 12V DC
  • Low Noise Regulation: Multiple LDO regulators

💻 Software

The complete FORGE software, along with its full implementation for the OSCAR P01A01 platform, is hosted in the following repository: Software_OSCAR_P01A01 https://github.com/DADDesign-Projects/Software_OSCAR_P01A01.
The OSCAR software stack is built around the DAD_FORGE framework (Framework for Open and Resourceful Guitar Effects): https://github.com/DADDesign-Projects/DAD_FORGE.
DAD_FORGE provides the complete software architecture: audio processing pipeline (DSP), parameter system, embedded user interface, preset management, and integration with OSCAR hardware modules.
It enables developers to quickly create modular and professional-grade audio effects (delay, chorus, tremolo, etc.) without having to rebuild the entire infrastructure from scratch.

🛠 Implementation & Development Setup

💻 Software Development

OSCAR’s firmware is developed using STM32CubeIDE, the official IDE from STMicroelectronics for STM32 microcontrollers.
It provides the compiler, debugger, HAL libraries, CubeMX configuration, and all tools required to build the firmware. Download STM32CubeIDE here:
https://www.st.com/en/development-tools/stm32cubeide.html

🔧 QSPI Loader/Flasher utility

OSCAR_P01_FlasherLoader combines a bootloader and a flashing client. In conjunction with OSCAR_Flasher_Server, it allows transferring files (samples, images, fonts, ELF executables, etc.) from a PC to the QSPI flash memory of the OSCAR_P01 board via USB.

When an ELF file is stored as an executable in the bootloader interface, the bootloader automatically loads it into RAM at power-up and starts its execution.

https://github.com/DADDesign-Projects/OSCAR_P01_FLasherLoader

https://github.com/DADDesign-Projects/OSCAR_Flasher_Server

🧩 Hardware Development

All hardware for OSCAR (processor board, audio board, connectors, etc.) is designed using KiCad 9.0, a fully open-source EDA suite. Download KiCad 9.0 here:
https://www.kicad.org/

🛠 Mechanical Design

Enclosures, mechanical parts, knobs, and button components for OSCAR are developed using FreeCAD, an open-source parametric 3D CAD tool. Download FreeCAD here:
https://www.freecad.org/

📬 Contact

Feel free to contact me for any questions, feedback, improvement suggestions, or collaboration proposals related to the FORGE framework or the OSCAR hardware platform. I am always open to discussion and community contributions (daddesign.projects@gmail.com).

📷 Image Gallery

proto

Harware

GUI