Echo is an open hardware platform for music players. The goal of the project is to produce a high quality music player, based on and designed with free software. It's primarily designed to run Rockbox, a free music player firmware with support for many codecs, and a wide array of features.
KiCAD 8.0 was used for the electrical design and PCB layout. The planned 3D-printable case will be designed using FreeCAD. The designs themselves are available under the CERN-OHL-S v2 license.
The current version of the Echo player is called the Echo R1. In the future, there could be new player models if there are significant changes to the features or form factor, but old models will always be supported.
- Size: 60x100x15mm (approx)
- Weight: TBD
The R1 has a 4-way D-pad and 6 multi-function buttons on the faceplate, which can be used to quickly navigate your music library and control playback. There are dedicated volume and power buttons (not pictured), and a sliding hold switch near the power button, which locks the buttons against accidental presses when the player is in your pocket or bag.
There are two 3.5mm jacks, one for headphones, and one true line-out port. The headphone jack supports recording from an in-line microphone and playback control by an in-line remote. Both jacks can be used simultaneously.
The removable memory card slot allows up to 2 TiB of storage for your music and files. The USB-C port is used for charging and file transfer, and supports high-speed USB 2.0.
The battery socket accepts the widely available BL-5C battery, and the battery can easily be replaced without special tools when it starts to wear out.
| Component | Description |
|---|---|
| CPU | STM32H743 @ 480 MHz |
| Memory | 32 MiB SDRAM @ 120 MHz |
| Audio | TLV320AIC3104, up to 96 KHz, 0.707 V RMS |
| Display | 18-bit, 320x240, 2.3 inch LCD |
| Storage | Expandable external memory card slot |
| USB | USB 2.0 @ 480 Mbps (High-speed) |
| Headphone out | Yes (3.5mm jack) |
| Line out | Yes (3.5mm jack) |
| Microphone | Can use wired headphone mic |
| RTC | Yes, with wake-up alarm function |
| Battery | Replaceable BL-5C battery (~1000 mAH) |
The Rev1 prototype PCB is complete but has some problems (see the list of known issues below). A 3D-printable case for the Rev1 is planned, but CAD files aren't available yet.
Development is currently focused on two areas:
- Porting Rockbox to the Rev1 board to identify any issues with the hardware design.
- Designing a case to test general usability and ergonomics, and find issues with the mechanical design of the PCB.
The next revision will be focused on addressing issues from Rev1.
- The backlight cannot be disabled, power is supplied to the LEDs even when the boost converter is disabled.
- The current limit on the backlight LED driver is set too low (20 mA paralleled to 4 LEDs, should be 20 mA per LED).
- Reference designators in the schematics don't make much sense, there are gaps in the numbering and samed-valued components are not in contiguous ranges.
Unless otherwise noted, all files in this repository, including
this README, are available under the terms of the CERN-OHL-S
version 2 license, which should be found in the file COPYING.txt
alongside this README; or at https://ohwr.org/cern_ohl_s_v2.txt.
Copyright (C) 2024-2025 Aidan MacDonald