Announcement: Audio Widget project
The Audio Widget project is open-source code and schematics for
USB based digital audio. It has functional firmware and software. And
it sounds good!
Cool? You bet! Here you can get started with USB audio without
worrying too much about the USB part of things.
Or you can contribute to a great open-source coding project. The
most important contribution we could need right now is coders for
USB Audio Class 2 drivers on Windows. But other efforts are needed
too. See below.
The code is written in C for the Atmel AT32UC3A3256 32-bit MCU. It
supports USB Audio Class 1.0 and 2.0 (UAC2). On Windows / UAC1 it
works with 24/44.1 and 24/48 with sample skip/insert. Asynchronous
USB is in progress, and we could use your help.
On Linux (>2.6.37) and OS X, using asynchronous USB, it also
supports 24/88.2, 24/96, 24/176.4 and 24/192. The open-source
firmware is in a git repository. It can be selectively compiled to run
on the three different boards. The firmware includes several UI and
There are three hardware options. The hardware is in a beta state. It
plays music very well, but there is still tweak potential.
1) A stand-alone USB-DAC with stereo audio playback functions only.
This board uses the ES9022 DAC chip. Contact
george.boudreau@YoyodyneConsulti... for info on how to obtain
one. More information on the this and other audio designs visit
http://www.yoyodyneconsulting.ca... ... dware.html
2) USB-I2S module + Analog Board. The module has all the pinouts you
need for digital audio, GPIO, I2C, SPI, LCD display and UART debug.
The module uses 2.0mm pitch pin rows. The Analog Board uses the
module to do stereo playback with an ES9022 DAC and low-noise
VBUS-LDO based power. AB-1 is a straightforward design to begin with,
and if you're into analog tweaking we challenge you to make your own
versions! Schematics and BOM are on
Go to http://www.qnktc.com/mod_ab1/ for more information. Contact
email@example.com to obtain a kit.
3) SDR-Widget Beta 2.0. This is the original fork of the project,
open-source HAM radio. The hardware supports both playback and
record. Contact george.boudreau@YoyodyneConsulti... for info
on how to obtain one. Visit
for more information of pricing and availability.
For more information, go to http://code.google.com/p/sdr-wid...
This announcement is cross-posted. Please join the mailing lists of
both SDR-Widget and Audio-Widget to continue the discussion there.
SDR-Widget is the original branch, where most of the firmware
discussions take place.
Feel like contributing? We'd always like to see more hands. There's
quite a few tasks planned:
- Firmware for Asynchronous UAC1 / Windows for 44.1 and 48ksps.
- Analog tweaks. Ideas are welcome for PSU, DAC, IVC, preamp etc.
Feel free to make suggestions, or even better, your own Analog
Board for the USB-I2S module.
- Windows open-source drivers for USB Audio Class 2.0. This
protocol is supported in Linux and OS X kernels, but not yet
- Adding more IO control to the firmware