An SF2 (SoundFont 2) based wavetable synth designed specifically for the ESP32-S3 microcontroller. This project leverages the enhanced memory capabilities of the ESP32-S3 (with PSRAM) to efficiently load and play SoundFont samples, providing a compact and powerful sampler solution. It's cheap and simple, yet powerful.
The ESP32-S3 SF2 Sampler is a sampler firmware that runs exclusively on the ESP32-S3 variant due to its improved PSRAM and memory management compared to the original ESP32. It supports external DACs like the PCM5102 for high-quality audio output and uses the built-in USB hardware of the ESP32-S3 to function as a USB MIDI device. By default, the BOOT button of the DevBoard is configured to cycle through SF2 files on the current filesystem. Long press on BOOT button will switch between Flash LittleFS and SD filesystems.
- SF2 playback: Load SoundFont2 banks up to PSRAM size.
- Filesystem: Runtime switch between LittleFS and fast 4-bit SD_MMC.
- USB MIDI: Plug-and-play MIDI device support.
- Per-voice filters: Optional biquad LPF (configurable in
config.h). - Per-channel filters: Optional CC#74/71-controlled LPF/resonance.
- Effects: Reverb (CC#91), Chorus (CC#93), Delay (CC#95).
- MIDI control: GM, partially GS/XG-compatible CCs, PC, RPNs, drums on ch.10, GM reset.
- External DAC: Works with PCM5102 and similar I2S DACs.
- ESP32-S3 optimized: Dual-core, PSRAM, minimal wiring.
- ESP32-S3 microcontroller with PSRAM (OPI PSRAM recommended)
- External DAC (e.g., PCM5102)
- USB connection for MIDI and power
| Signal | GPIO Pin |
|---|---|
| BCK | GPIO5 |
| DTA | GPIO6 |
| WCK | GPIO7 |
| CS | GND |
| Signal | GPIO Pin |
|---|---|
| CMD | GPIO38 |
| CLK | GPIO39 |
| D0 | GPIO10 |
| D1 | GPIO11 |
| D2 | GPIO12 |
| D3 | GPIO13 |
| VCC | 3V3 |
| GND | GND |
These pins can be changed in config.h if needed
To build and upload this project using Arduino IDE, configure the following settings:
- PSRAM: Select OPI PSRAM
- Partition Scheme: Choose a partition with the most available SPDIFF space
- USB Mode: Select TINY USB
- Core Debug Level: Set to Info or lower (higher debug levels may block USB functionality)
- Upload SF2 files to internal Flash: use this plugin for Arduino IDE 2.x.x https://github.com/earlephilhower/arduino-littlefs-upload , or ths one https://github.com/earlephilhower/arduino-esp8266littlefs-plugin if you use Arduino IDE 1.x
- Wire a microSD or SD card to have a lot of SF2 files to choose from
- Connect your ESP32-S3 board with PSRAM and external DAC according to the pinout above.
- Load your preferred SF2 SoundFont files onto the device (refer to project documentation for details on loading SF2 files).
- Connect the ESP32-S3 via USB to your computer or MIDI host.
- The device will enumerate as a USB MIDI device, allowing you to play samples via MIDI input.
- This project is only compatible with the ESP32-S3 due to memory and PSRAM requirements.
- Using a core debug level above Info may interfere with USB MIDI functionality.
- Ensure your external DAC is properly powered and connected for optimal audio quality.
Contributions, issues, and feature requests are welcome! Feel free to open a pull request or issue on the GitHub repository.
This project is licensed under the MIT License. See the LICENSE file for details.
Enjoy your ESP32-S3 powered sampler!