FreeDSP AURORA User manual

USER MANUAL
FREEDSP-AURORA
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REVISION HISTORY
Revision
Description
Date
v1.0.0
Initial Version
01 Jul 2019
v1.0.1
Regulatory Information and WiFi setup rewritten
31 Jul 2019
v1.0.2
Updating ESP32 firmware via USB
30 Aug 2019
v1.0.3
Fixed wrong picture for X102, added pinout for USBi, added
WiFi antenna connection
13 Sep 2019
v1.1.1
webOTA added, AddOn configuration
10 Nov 2019
v2.0.0
Added 4FIRs plugin, connector volume pot, WebApp, Quick
start
9 Mar 2020
v2.0.1
Added hint polarity inversion
15 Mar 2020
v2.0.2
Added fallback
29 Mar 2020
v2.0.3
Added hint for Send button
03 Apr 2020
v2.1.0
Reorganized connectivity chapter
Specification recommended operating conditions
09 Jun 2020
v2.1.1
Added Access Point Config
Added Turning Off WiFi
Added SPDIF Output Routing
18 Jul 2020
v2.1.3
Removed obsolete paragraph on page 6
Fixed typo on page 26
2 Oct 2020
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Revision History!2"
About freeDSP-aurora!5"
Important Information!7"
Features!8"
Quick Start!9"
System Information!10"
Block Diagram!10"
Connectors!11"
Recommended Operating Conditions!12"
Optional Input and Output AddOns!13"
How To Get freeDSP-aurora Up And Running!14"
Hardware Installation!14"
Software Installation!14"
Examples for optional peripherals!22"
Volume Potentiometer!23"
Rotary Encoder!24"
IR Receiver!25"
Display!26"
Working with the Web Application!27"
Overview!28"
Config Device!30"
WiFi Configuration!32"
Uploading a DSP Plugin!33"
Storing Parameter Settings!34"
Exporting Parameter Settings!34"
Importing Parameter Settings!35"
Master Volume!35"
S/P-DIF output!35"
Fallback!35"
Turn OffWifi!35"
DSP Plugins!36"
8channels!36"
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HomeCinema71!38"
4FIRs!40"
Updating the Firmware via USB!42"
Preparing for Update!42"
Uploading the Firmware!43"
Updating the Firmware via webOTA!49"
Uploading the Firmware!49"
Disclaimer!51"
Warranty!51"
Regulatory Information!52"
Licenses!53"
Useful Web Links!55
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ABOUT FREEDSP-AURORA
The freeDSP-aurora is a cost-effective real-time audio signal processing solution for
researchers and the do-it-yourself community and audio enthusiasts. It is a bare circuit board
that can be incorporated into your own projects. It comes with no housing. Easy assembling
and simple programmability are the main focus. It is based on Analog Devices’ ADAU1452
DSP controlled by a web application.
Additionally the development environment SigmaStudio can be used. The programming
model of SigmaStudio is function-block based – comparable to other graphical programming
languages like PureData or Max/MSP. Many prebuilt blocks (e.g., filters, compressors, effects,
or logic) can be placed in the signal path via drag and drop. If the included libraries do not
have the functions needed, low-level blocks, such as multipliers and delays, can be wired
together to create custom DSP plugins. For more information please refer to the Analog
Devices website (https://www.analog.com/en/design-center/evaluation-hardware-and-
software/software/ss_sigst_02.html#software-overview).
FreeDSP-aurora offers a wide range of DSP processing options and interface controls with
easy programmability. It can be used in various audio applications, e.g.:
Room compensation / system equalization
Digital crossovers in active loudspeaker concepts
Multiband dynamics processing
Delay compensation / phase shift
Bass enhancement
Subwoofer integration
Advanced instrument audio effect units
Stereo image widening
…
A XMOS XE216-512-TQ128 MCU is used to expose an USB Audio Class 2 compliant
interface to a host computer running macOS, Linux or Windows 10. The boards provides 8
balanced audio input and 8 balanced audio output channels. Additionally an ADAT input/
output and a Wordclock input/output is provided by the XMOS MCU.
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The ESP32 MCU controls the operation of the DSP. Furthermore, it provides WiFi and
Bluetooth connectivity and handles peripherals like rotary encoder, display, temperature
sensor, PWM controlled fan and IR sensor.
The complete schematics and all software for the freeDSP-aurora board are published under
a Creative Commons Attribution ShareAlike 4.0 International (CC BY-SA 4.0) license, which
allows the unrestricted use and modification of the module. This means that experienced
users can make their own version of the board, extending it and improving it, as long as they
credit freeDSP and auverdion and release their designs under the same license.
The freeDSP brand and freeDSP logo are copyright of Sebastian Merchel and Ludwig
Kormann and cannot be used without formal permission.
The auverdion brand is copyright of Raphael Knoop and cannot be used without formal
permission.
This user manual is published under the same CC license.
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IMPORTANT INFORMATION
The freeDSP-aurora board might generate signals that may damage your audio equipment.
Please read and understand this manual before starting to work with your board. Adjust all
hardware settings and configure your software before connecting any audio equipment to
freeDSP-aurora. Always start with low volume on your amplifier and slowly increase the level
to reduce the risk of damaging your audio system.
freeDSP-aurora is provided to you ‘as is’. Auverdion makes no express or implied warranties
whatsoever with respect to its functionality, operability, or use, including, without limitation,
any implied warranties of merchantability, fitness for a particular purpose, or infringement. We
expressly disclaim any liability whatsoever for any direct, indirect, consequential, incidental or
special damages, including, without limitation, lost revenues, lost profits, losses resulting from
business interruption or loss of data regardless of the form of action or legal theory under
which the liability may be asserted, even if advised of the possibility or likelihood of such
damages. Features and specifications might change without prior notice.
Please keep in mind that freeDSP-aurora is an open-source project. Because freeDSP-aurora
is very flexible, many applications are possible. Questions and new ideas can be discussed
online with other DIYers. Please use the Digital Line Level subforum @ diyAudio.com or the
Elektronik subforum @ www.diy-hifi-forum.eu to connect with other people working with
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freeDSP-aurora. Please create individual threads for your topics only if you cannot find your
issue in the existing threads. Some questions can be answered by carefully reading this
manual.
This manual refers to firmware version 2.1.3.
Please see chapter Useful Web Links
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FEATURES
• Analog Devices ADAU1452, 294.912 MHz, 32-bit SigmaDSP
6144 SIMD instructions per sample @ 48 kHz fs
40kWords of data RAM
800 ms digital audio delay pool @ 48 kHz fs
8 stereo ASRCs with 139 dB DNR
• XMOS XE216-512-TQ128 for multichannel bidirectional audio streaming
• ESP32 for WiFi or Bluetooth control
• AKM AK4458 32bit-DAC
• AKM AK5558 32bit-ADC
• Supporting sample rates between 44.1 kHz and 192 kHz
• 8 analog balanced input channels, +6 dBu
• 8 analog balanced output channels, +6 dBu
• S/P-DIF input and output
• ADAT input and output
• Wordclock input and output
• Support for display, rotary encoder, volume potentiometer, temperature sensor,
PWM controlled fan, IR sensor
• One freeDSP expansion header
• USB Audio Class 2 Bidirectional streaming with 8 channels in and 8 channels out,
full-duplex. Works with ASIO driver under Windows 10 and driverless under macOS
and Linux.
• Realtime control via a web application supporting Safari, Chrome and Firefox.
• Connection to board by WiFi
• Board dimensions: 110 mm x 110 mm
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QUICK START
For a quick start with your brand new freeDSP-aurora you just have to do the following steps:
1. Get some chocolate.
2. Connect your add on (if you have one) to your freeDSP-aurora.
3. Connect your audio equipment to freeDSP-aurora (or the addon).
4. Connect X105 to your power supply.
5. Connect the WiFi antenna.
6. Eat some chocolate.
7. Power up your freeDSP-aurora.
8. Connect your computer to the access point AP-freeDSP-aurora.
9. Open Safari or Firefox or Chrome and enter 192.168.5.1 in the URL field.
10.Get a cup of coffee and eat the rest of the chocolate.
11.Your are ready for DSP’ing.
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SYSTEM INFORMATION
BLOCK DIAGRAM
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CONNECTORS
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8 channel
analog
output pin
header
8 channel
analog
input pin
header
power supply
USB Audio 2
freeDSP
expansion
USBi
IR remote
ADAT
S/P-DIF
Wordclock
Rotary Encoder
PWM fan &
temperature
sensor
volume
potentiometer
Power LED

RECOMMENDED OPERATING CONDITIONS
Absolute Maximum Ratings
Note: Operation at or beyond the limits in the table above may cause permanent damage to
the device and normal operation is not guaranteed at these extremes.
FreeDSP-aurora has to be placed in an enclosure with enough airflow. Please mount the PCB
with spacers on a solid surface. None of the four mounting holes is connected to any voltage
or signal on the board. EMC regulations must be observed.
Item
Min
Typ
Max
Unit
Notes
Supply Voltage
6.5
7
10
Vdc
Input Level
6
dBu
Might be changed by
AddOn
Output Level
6
dBu
Might be changed by
AddOn
Item
Min
Typ
Max
Unit
Notes
Supply Voltage
6
12
Vdc
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OPTIONAL INPUT AND OUTPUT ADDONS
FreeDSP-aurora was designed to support as many applications as possible. Therefore, all
inputs and outputs are on pin headers or ribbon cable connectors. This way user can adapt
the front-ends to their needs. Some add-on boards will be available for this project. These
boards will cover the most common used input output configurations, e.g. active multi-way
loudspeaker or an 8 channel loudspeaker management or buttons and displays for user
interaction. Please check the github repository and/or the website for information about the
add-on boards.
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HOW TO GET FREEDSP-AURORA UP AND RUNNING
HARDWARE INSTALLATION
Before you can use freeDSP-aurora you may have to do some hardware connections. The
connections vary with desired application. Not all connections are always needed. At least
you have to connect the WiFi-Antenna and the power supply to get your freeDSP-aurora
working.
SOFTWARE INSTALLATION
USB Driver Installation
FreeDSP-aurora was designed to be class compliant with UAC2. Thus, on macOS and Linux
you don’t need to install any driver. Windows 10 comes with a UAC2 driver as well but you
may have to install additional stuff like the free software asio4all and your audio software
needs to support ASIO. Please note, that ASIO is only needed if you want to use the 8 input
channels for recording audio. If you just want to use freeDSP-aurora to stream audio data to
your audio equipment, ASIO is not needed and you can skip the asio4all installation.
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WiFi Antenna
Your freeDSP-aurora comes with a WiFi antenna. If you want to control your DSP via WiFi you
have to connect the antenna on the antenna connector of the WiFi module (ESP32).
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Analog Audio Connections
Analog audio input connections can be made on pin header X201. The audio inputs are
designed for balanced operation at +6 dBu maximum input level. Unbalanced sources can
be connected as well by grounding the negative input. In the latter case you may have to
change the gain of the input stage to improve the signal to noise ratio. Alternatively you may
want to use a conversion circuit if your audio sources use a different connection (e.g
unbalanced) or have another level.
Analog audio output connections can be made on pin header X301. The audio outputs are
designed for balanced operation at +6 dBu maximum output level. In case of unbalanced
sinks leave the negative output unconnected. In the latter case you may have to change the
gain of the output stage to improve the signal to noise ratio. Alternatively you may want to
use a conversion circuit if your audio sinks use a different connection (e.g. unbalanced) or
have another level.
When making audio connections, make sure that your equipment is powered off to avoid any
damage.
The gain of the analog audio input and output stage can only be changed by changing the
resistors on the board to another value.
Connector: IDC26, 2.54 mm Pitch, Bud Industries, BC-32677
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!
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Pin 1
Pinout Analog Input
Pin 1
Pinout Analog Output

Digital Audio Connections
On connector X101 you can make your digital audio connections like S/P-DIF input and
output and ADAT input and output. Wordclock input and output can be connected to X101,
too.
Connector: MicroMatch-14, 2.54 mm pitch, TE Connectivity AMP Connectors, 1-215079-4
FreeDSP Expansion Header
X102 is the an expansion header for additional input and output boards. The pinout complies
with the I2S expansion header specification of the freeDSP project. If you want to connect a
I2C display please connect it to this header, too.
Connector: Header 2 x 8 pos, 2.54 mm pitch, Sullins Connector Solutions, PRPC008DAAN-
RC
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Pinout Digital Audio Connections
Pinout freeDSP Expansion Header
Pin 1
Pin 1

USBi Connector
On connector X104 you can connect an USBi programmer. The pinout complies the
pinout of the programmer from Analog Devices but you have to make a flatband ribbon
cable with a MicroMatch connector on one side."
Connector: MicroMatch-10, 2.54 mm pitch, TE Connectivity AMP Connectors,
1-215079-0"
"
Fan and Temperature Sensor
On connector X501 you can connect a PWM controlled fan. Please use the Sense pin to
connect a temperature sensor (e.g. NTC).
Connector: KK-100, 4 pos, 2.54 mm pitch, Molex, 0022232041
Rotary Encoder
On connector X502 you can connect a rotary encoder with or without a push button.
Connector: PicoBlade, 5 pos, 1.25 mm pitch, Molex, 530470510
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Pin 1
Pinout Fan and Temperature Sensor
Pin 1
Pinout Rotary Encoder
Pin 1
Pinout USBi Connector

IR Sensor
On connector X503 you can connect an infra red receiving diode.
Connector: PicoBlade, 3 pos,1.25 mm pitch, Molex, 530470310
Volume Potentiometer
On connector X103 you can connect volume potentiometer for master volume control.
Please connect the center tap of your potentiometer to pin 2 of X103 and the other two taps
to pin 1 and 3. If the turn direction of the potentiometer is not right then you have to swap the
cables on pin 1 and pin 3.
Connector: PicoBlade, 3 pos,1.25 mm pitch, Molex, 530470310
USB Connection
Your host computer connects on the pin header X401. Please use a common off-the-shelf
cable assemblies (typically used in computer hardware). Always confirm the pin-out with the
manufacturer, or you could easily cause damage to your computer or freeDSP-aurora.
Usually the GND-pins 4 and 5 can be identified by a black wire, but you can never be sure
unless you checked the manufacturer’s specifications of the connector.
Connector: Header, 5 pos, 2.54 mm pitch, Sullins Connector Solutions, PRPC005SAAN-RC
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Pin 1
Pinout IR Sensor
Pin 1
Pinout USB Connection
Pin 1
Pinout Master Volume