# DA15 — USB-C Audio DAC + Amplifier

Year: 2026  
Type: Personal  
Category: embedded  
Page: https://eliachiarucci.com/projects/da15

Open-source USB-C DAC+amp on STM32H503. Driverless 24-bit/48kHz stereo audio with multi-band EQ, smart power detection, and OLED interface.

## Overview

DA15 is a compact, USB-powered digital-to-analog converter and headphone amplifier built around the **STM32H503** microcontroller. It delivers driverless 24-bit/48kHz stereo audio via USB Audio Class 1, with a custom multi-band equalizer using Q12 fixed-point math for bass and treble processing.

The board features smart USB-C power detection that adapts amplifier output across three power tiers (500mA, 1.5A, 3A), a 128x64 SH1106 OLED display with rotary encoder navigation, and DFU firmware update capability. Settings are stored in flash with wear-leveling protection.

Hardware design uses the PCM5102A DAC and PAM8965 amplifier, with both software (GPL-3.0) and hardware (CERN-OHL-S-2.0) released as open source.

## Key Features

- USB Audio Class 1 — driverless 24-bit/48kHz stereo streaming
- Multi-band equalizer with custom Q12 fixed-point DSP
- Smart USB-C power detection (500mA / 1.5A / 3A tiers)
- 128x64 SH1106 OLED display with rotary encoder UI
- DFU firmware updates over USB
- Flash-based settings with wear-leveling protection
- Open-source hardware (CERN-OHL-S-2.0)

## Tech Stack

C, STM32H503, STM32 HAL, TinyUSB, CMake, PCM5102A, PAM8965

## Links

- GitHub: https://github.com/eliachiarucci/DA15