USOUND HELIKE 1.0 UA-E3010 User manual

DEVELOPMENT BOARD
Helike 1.0 UA-E3010 is a development
board for assessing multiple USound
MEMS speaker-based products for rapid
prototyping. The evaluation board is
designed to function in three modes
—standalone, as USB audio device
(UAC 2.0) or as an extension board to
a Raspberry Pi platform with 40 Pin
GPIO interface. Helike 1.0 UA-E3010
also contains a set of ampliers to
drive two MEMS speakers and two
electrodynamic speakers along with
multiple supply options.
HELIKE 1.0 UA-E3010 | USER MANUAL
FEATURES
Standalone mode (SD card playback)
USB Audio Device (UAC 2.0)
Raspberry Pi platform via I2S interface
Multiple supply options, depending on the
availability and application
Compatible with several USound audio
products
2 x MEMS ampliers
2 x electrodynamic speaker ampliers
Digital audio equalizer
Dynamic compression algorithm for MEMS
speakers
SD-Card slot
Joystick for playback control
Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [e-mail]

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [e-mail]
CONTENT
1. OVERVIEW................................................................................................................................................... 5
2. REQUIRED ADDITIONAL PARTS .............................................................................................................. 5
3. BEFORE GETTING STARTED ..................................................................................................................... 5
4. PCB LAYOUT................................................................................................................................................ 6
4.1. TOP LAYER.................................................................................................................................................... 6
4.2. BOTTOM LAYER .......................................................................................................................................... 6
5. SUPPLYING THE HELIKE 1.0 UA-E3010 BOARD.................................................................................... 7
5.1. USB SUPPLY................................................................................................................................................. 8
5.2. EXTERNAL 36 V SUPPLY .......................................................................................................................... 8
5.3. EXTERNAL 5 V ............................................................................................................................................. 9
5.4. 5 V SUPPLY FROM EXPANSION HEADER............................................................................................ 9
6. AUDIO INPUT CONFIGURATION .............................................................................................................. 9
6.1. STANDALONE MODE................................................................................................................................. 9
6.1.1. SD card input ..................................................................................................................................................................9
6.1.2. USB input...................................................................................................................................................................... 10
6.2. SLAVE MODE..............................................................................................................................................10
6.2.1. I2S input ........................................................................................................................................................................ 10
6.3. OVERVIEW..................................................................................................................................................10
7. OUTPUT CONFIGURATION......................................................................................................................11
7.1. CARME SPEAKER BOXES ....................................................................................................................... 12
7.1.1. DIP switch settings.................................................................................................................................................... 12
7.1.2. Speaker attachment .................................................................................................................................................. 13
7.2. FOR DIONE MAXI UY-R3020..................................................................................................................13
7.2.1. DIP switch settings.................................................................................................................................................... 13
7.2.2. Speaker attachment .................................................................................................................................................. 14
7.3. FOR DIONE MINI UY-R3010 ...................................................................................................................14

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
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7.3.1. DIP switch settings.................................................................................................................................................... 14
7.3.2. Speaker attachment .................................................................................................................................................. 14
7.4. FOR DANUBE 5.0 UAM-P2050..............................................................................................................15
7.4.1. DIP switch settings.................................................................................................................................................... 15
7.4.2. Speaker attachment .................................................................................................................................................. 16
8. CREATING A HELIKE 1.0 UA-E3010 CONFIGURATION FILE ..............................................................16
8.1. CUSTOMIZE A HELIKE 1.0 .JSON FILE .................................................................................................16
8.2. FILTER CONFIGURATION........................................................................................................................17
8.3. DRC CONFIGURATION ............................................................................................................................18
8.4. CONVERT .JSON FILE TO .BIN FILE ......................................................................................................19
8.5. PLACE FILE ON MICROSD CARD AND SET DIP SWITCHES .........................................................20
9. INTERFACES...............................................................................................................................................20
9.1. JOYSTICK .....................................................................................................................................................20
9.2. BUTTONS ....................................................................................................................................................21
9.3. LEDS .............................................................................................................................................................21
10. FIRMWARE UPDATE ..............................................................................................................................21
10.1. UPDATE VIA USB-C PORT .....................................................................................................................21
10.2. FIRMWARE UPDATE TROUBLESHOOTING.......................................................................................25
10.2.1. Helike 1.0 UA-E3010 is not detected as DFU device in the DefuSe software ................................. 25
10.2.2. Installing DFU drivers manually......................................................................................................................... 25
10.3. UPDATE VIA SWD INTERFACE.............................................................................................................26
11. TROUBLESHOOTING..............................................................................................................................26
11.1. .WAV AUDIO REPRODUCTION.............................................................................................................26
11.2. ACOUSTIC CANCELLATION ON LEFT CHANNEL IN A TWO-WAY SPEAKER SYSTEM ........27
11.3. EQUALIZATION FILTER IMPLEMENTATION EXAMPLE...................................................................27
11.3.1. Open sample.json file ............................................................................................................................................ 27
11.3.2. Generate coefficients.............................................................................................................................................. 27

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
11.3.3. Copy coefficients to .json file............................................................................................................................... 27
11.3.4. Convert to .bin and copy to MicroSD card ...................................................................................................... 28
REVISION HISTORY
November 2020: first release.
February 2021:
Updated connector name from J4 to J2, page 8.
Corrected sampling rate information in section 6.1.1, page 9.
Corrected entries in table 4 for I2S slave configuration, page 10.
Added DRC configuration section, page 18.
Added instructions for firmware update via USB-C connector, page 21.
March 2022:
Added Carme Kit to compatible product table, page 5 and page 10.
Add JsonBsonConverter Instruction, page 19.
Add instructions for DFU driver installation and manual DFU driver installation, pages
21-25. Added Troubleshooting section, page 26
June 2022:
Added filter configuration example, page 2
Updated Carme Kit connection section, page 11.

5
Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
1. OVERVIEW
USound MEMS speakers offer a series of advantages compared to traditional electrodynamic speakers. The
Helike 1.0 UA-E3010 development board enables the evaluation of USound MEMS speakers and the
following USound extension kits:
Table 1: Helike 1.0 UA-E3010 compatible USound products and the corresponding connectors
2. REQUIRED ADDITIONAL PARTS
The Helike 1.0 UA-E3010 development board is delivered with a MicroSD card that can be used to store
filter coefficients and audio files for playback. Note that the MicroSD card is empty when delivered, and the
user must place the desired files (media, configuration files).
Depending on which of the above products will be tested, the corresponding extension kit must be
acquired separately.
3. BEFORE GETTING STARTED
Before getting started, we recommend updating the Helike 1.0 UA-E3010 firmware to the latest available
version. The open-source firmware is available from the public git repository
under https://github.com/usound-audio/Helike 1.0. The compiled firmware files are in the public git
repository under https://github.com/usound-tech/audio_device_configuration in the “release” folder. They
can be used to update Helike 1.0 UA-E3010 via the USB port. Find details in the Firmware update section.
Extension kits
Description
Connector
Dione Maxi UY-R3020
Bendable MEMS speaker array with
external amplifier board
Dione Maxi UY-R3020 connector
Dione Mini UY-R3010
Bendable MEMS speaker array with
integrated amplifiers, extendable
Dione Mini UY-R3010 connector
Carme 3.0 UJ-R1030
Speaker box designed for testing the
performance of MEMS speakers. Can be
fitted with Adap or Achelous speakers.
2.54 mm header from MEMS amp
Danube 5.0 UAM-P2050
Audio module combining a MEMS
tweeter and an electrodynamic woofer
in a 2-way system
2.54 mm header from MEMS and
electrodynamic amp
Carme Kit Ganymede
UJ-E1040G00
Speaker evaluation kit designed for
testing the performance of USound
Ganymede MEMS speakers. Can be
fitted with Adap or Achelous speakers.
2.54 mm header from MEMS amp

6
Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
4. PCB LAYOUT
Figure 1 and Figure 2 show the component placement on the PCB.
4.1. TOP LAYER
Figure 1: Component placement on the top layer of the PCB, supply jumpers highlighted
4.2. BOTTOM LAYER
Figure 2: Component placement on the bottom layer of the PCB

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
5. SUPPLYING THE HELIKE 1.0 UA-E3010 BOARD
The Helike 1.0 UA-E3010 board has four supply options for the microcontroller and its peripherals: USB,
5 V external, 36 V external, and 5 V via Raspberry Pi header. The used supply input depends on the user’s
preference and the used output device. Figure 3 shows the block diagram of the supply lines in the
Helike 1.0 UA-E3010 development board.
Figure 3: Helike 1.0 UA-E3010 supply block diagram
Jumpers JP1, JP2, JP3 and JP4 are used to select the power supply. Note that only one of these jumpers
should be set at a time.
The output device dictates the power consumption of Helike 1.0 UA-E3010. Refer to Table 2 to see which
output device can be used in conjunction with the different power supplies and the limits that apply.

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
Table 2: Helike 1.0 UA-E3010 supplies and compatible products
1) The copper lines of VCC_36V0 are designed for a current rating of 2 A. One Dione Maxi UY-R3020 sound strip —in
conjunction with an Amalthea 2.0 UA-R3020 amplifier, has a maximum current consumption of 275 mA (20 kHz). Providing
that the power supply can source sufficient current, up to seven Dione Maxi UY-R3020 sound strips can be attached to the
outputs.
2) The copper lines of VCC_5V0_EXTERNAL are designed for a current rating of 10 A. Dione Mini UY-R3010 has a maximum
current consumption of 900 mA (per segment, 20 kHz). Since the power supply can source sufficient current, up to ten
Dione Mini UY-R3010 segments can be attached to the outputs. In a typical use case, the current drawn by one
Dione Mini UY-R3010 segment should not exceed 21 mA.
3) A Carme speaker box (Carme 3.0 UJ-R1030 or Carme Kit Ganymede UJ-E1040G00 speaker box) has a maximum current
consumption of 180 mA (20 kHz). Since the power supply can source sufficient current, up to eight speaker boxes can be
attached to the Helike 1.0 UA-E3010 outputs (four per amplifier).
4) Up to four Danube 5.0 UAM-R2050 audio modules can be connected to Helike 1.0 UA-E3010.
For high current applications (>2 A on VCC_5V0_External and >2.5 A on VCC_36V) replace the respective
coaxial connectors with screw terminals. The respective THT holes are in place underneath the barrel
connectors. TE Connectivity PN 282836-1 are recommended.
5.1. USB SUPPLY
To supply the Helike 1.0 UA-E3010 PCB via the built-in USB-C connector, set a jumper to location JP1.
Ensure that no jumper is set at JP2, JP3, or JP4.
The Helike 1.0 UA-E3010 PCB is configured as USB slave device with a current draw of up to 3 A. When
using the USB supply scheme, ensure that the host device (e.g., a computer, a phone or a power bank) can
supply the required current.
5.2. EXTERNAL 36 V SUPPLY
The Helike 1.0 UA-E3010 PCB can be supplied externally with a voltage of 36 V via the barrel
connector J2. JP2 needs to be set to select this supply. An onboard DCDC converter is used to provide
suitable voltages to the microcontroller and peripherals.
The 36 V external supply is intended for use in conjunction with the Dione Maxi UY-R3020 output device.
The necessary Amalthea 2.0 UA-R3020 amplifier can then be directly supplied with power via the Dione
Maxi UY-R3020 output connector (J16).
Supply/Device
VBUS USB-C
(3 A @5 V)
VCC_36V0 from
barrel connector
VCC_5V0_EXTERNAL
from barrel connector
VCC_5V0_PI
RasPi header
Dione Maxi UY-R3020
No
Yes 1)
No
No
Dione Mini UY-R3010
No
No
Yes 2)
No
Carme 3.0 UJ-R1030
Yes 3)
Yes 3)
Yes 3)
Yes 3)
Carme Kit
Ganymede UJ-E1040G00
Yes 3)
Yes 3)
Yes 3)
Yes 3)
Danube 5.0 UAM-R2050
Yes 4)
Yes 4)
Yes 4)
Yes 4)

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
5.3. EXTERNAL 5 V
The 5 V external supply is selected by setting jumper JP3. The voltage source needs to be connected to the
P1J barrel connector (J4). Using this supply is mandatory when Dione Mini UY-R3010 is used as an output
device.
5.4. 5 V SUPPLY FROM EXPANSION HEADER
5 V can be supplied from the RaspberryPi expansion header (J17 Pin 2 and 4). This is achieved by setting
jumper JP4. A minimum current of 500 mA is required.
6. AUDIO INPUT CONFIGURATION
The Helike 1.0 UA-E3010 evaluation board has two input configuration options:
In standalone mode, the I2S clocks are generated by the STM32 microcontroller and audio signals can be
input via the USB-C connector (USB soundcard) or by reading audio files from a MicroSD card.
In slave mode, the input comes from a Raspberry Pi or another I2S source and is forwarded by the STM32
microcontroller to the DAC converters.
6.1. STANDALONE MODE
The standalone mode is selected by setting the DIP switch S1 position 8 (S1-8) to OFF. In standalone
mode, the STM32 is the master on all I2S clocks, and the MicroSD card, or the USB input can be selected as
audio sources.
To use the standalone mode the jumpers and solder bridges must be set according to Table 3.
Name
Status
Name
Status
Name
Status
JP5
Removed
JP10
Removed
R5
Irrelevant
JP6
Removed
JP11
Inserted
R6
Irrelevant
JP7
Removed
JP12
Removed
R7
Irrelevant
JP8
Removed
JP13
Removed
R8
Irrelevant
JP9
Removed
R4
Irrelevant
Table 3: Jumper and solder bridge settings for standalone mode
6.1.1. SD CARD INPUT
To select the MicroSD card as the audio source, set the DIP switch S1 position 7 (S1-7) to OFF. MP3 and
WAV files stored in the root directory on the MicroSD card will be played back automatically. The playback
of the files (play, pause, next track) can be controlled with the joystick as described in section 9.1. Note that
the sampling rate of the audio files must be 48 kHz.

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
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6.1.2. USB INPUT
The USB soundcard feature requires the operating system to support UAC 2.0 devices. For Windows, this
applies to Windows 10 build 1703 and later.
To select the USB input as the audio source, set the DIP switch S1 position 7 (S1-7) to ON. When
Helike 1.0 UA-E3010 is connected to a computer via the USB-C connector, it will appear in the operating
system as a stereo soundcard. Select the soundcard and reproduce audio content from the host device.
It is possible to supply Helike 1.0 UA-E3010 via an external supply (VCC_36V0, VCC_5V0, VCC_5V0_PI)
and simultaneously provide the audio data via the USB cable.
6.2. SLAVE MODE
The slave mode is selected by setting the DIP switch S1 position 8 (S1-8) to ON. In slave mode, the STM32
receives I2S audio data and clocks from a source device such as a RaspberryPi.
To use the slave mode the jumpers and solder bridges must be set according to Table 4.
Name
Status
Name
Status
Name
Status
JP5
Removed
JP10
Inserted
R5
Connected
JP6
Removed
JP11
Irrelevant
R6
Connected
JP7
Removed
JP12
Inserted
R7
Connected
JP8
Removed
JP13
Inserted
R8
Connected
JP9
Inserted
R4
Connected
Table 4: Jumper and solder bridge settings for slave mode
6.2.1. I2S INPUT
I2S data can be input to Helike 1.0 UA-E3010 via header J17. The pinout matches the RaspberryPi 40 pin
header and can be seen in the schematics. Helike 1.0 UA-E3010 expects audio data in I2S format with the
following specifications:
•16 bits of resolution
•BTCLK = 1.536 MHz
•FSCLK = 48 kHz, and the falling edge occurs before the first data bit
•Data must be MSB-first and is strobed on the rising edge of the bit clock
6.3. OVERVIEW
Table 5 shows the appropriate settings for DIP switches S1-7 and S1-8 for the three audio input modes.
Input configuration
DIP switch S1-7
DIP switch S1-8
SD card
Off
Off
USB
On
Off
I2S
Off
On
Table 5: DIP S1-7 and S1-8 positions to select audio input mode

11
Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
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7. OUTPUT CONFIGURATION
Helike 1.0 UA-E3010 supports multiple USound output devices shown in Table 1. Helike 1.0 UA-E3010
offers the possibility to load filters from the MicroSD card that optimize the acoustic characteristics of each
of the devices. The configuration files that are used for these devices can be downloaded from
https://github.com/usound-tech/audio_device_configuration. They must be copied onto the MicroSD card
and placed in a folder named “usound” as shown in Figure 4 for Helike 1.0 UA-E3010 to recognize and to
load the parameters.
Figure 4: Placement of configuration files on MicroSD card
Based on the output device selected, the DIP switches S1-1 through S1-4 need to be set accordingly. This
ensures that the correct configuration file is loaded from the MicroSD card, and hence that optimal sound
quality is reached for the corresponding device Table 6 shows the various DIP switch options.
Helike 1.0 UA-E3010 can be used without installing a MicroSD card in USB input and I2S input mode.
However, if configuration loading is enabled by setting DIP switches S1-1 through S1-4 to anything other
than 4x Off, no filter will be loaded, and Helike 1.0 UA-E3010 will playback audio without configuration.
This state is signaled by LED 3 (orange) illuminating or blinking.

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Released in November 2020, updated in June 2022
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S1-1
S1-2
S1-3
S1-4
SD configuration file
USound Device
Off
Off
Off
Off
N.A
Passthrough (default)
Off
Off
Off
On
config-1.bin
Dione Mini UY-R3010
Off
Off
On
Off
config-2.bin
Dione Maxi UY-R3020
Off
Off
On
On
config-3.bin
Danube 5.0 UAM-R2050
Off
On
Off
Off
config-4.bin
Carme kit UJ-E1040G00 speaker
box/Carme 3.0 UJ-R1030 equipped with
Adap speaker
Off
On
Off
On
config-5.bin
Carme kit UJ-E1040G00 speaker
box/Carme 3.0 UJ-R1030 equipped with
Achelous speaker 1)
Off
On
On
Off
config-6.bin
Available for user/custom configuration
Off
On
On
On
config-7.bin
Available for user/custom configuration
On
Off
Off
Off
config-8.bin
Available for user/custom configuration
On
Off
Off
On
config-9.bin
Available for user/custom configuration
On
Off
On
Off
config-10.bin
Available for user/custom configuration
On
Off
On
On
config-11.bin
Available for user/custom configuration
On
On
Off
Off
config-12.bin
Available for user/custom configuration
On
On
Off
On
config-13.bin
Available for user/custom configuration
On
On
On
Off
config-14.bin
Available for user/custom configuration
On
On
On
On
config-15.bin
Available for user/custom configuration
Table 6: DIP switch position for filter selection
1) Formerly this configuration slot was used for Sentia. Sentia is no longer supported.
7.1. CARME SPEAKER BOXES
Carme kit UJ-E1040G00 speaker boxes and Carme 3.0 UJ-R1030 speaker boxes can be fitted with a single
MEMS speaker (Adap or Achelous). Both can be connected to Helike 1.0 UA-E3010 in the same way as
described below. A total of four Carme speaker boxes can be attached to the Helike 1.0 UA-E3010 PCB via
Jumpers J12, J19, J14, and J20 (2x left, 2x right).
7.1.1. DIP SWITCH SETTINGS
To select the correct filter configuration for the Carme speaker being used, set the DIP switches S1-1
through S1-4, as shown in Table 6. This ensures that the correct filter coefficients are loaded into the audio
pipeline.

13
Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
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7.1.2. SPEAKER ATTACHMENT
Carme speaker box
The Carme speaker boxes use a two-pole cable with a 2 position 2.54 mm female header to interface
Helike 1.0 UA-E3010. Connect the Carme speaker box to the MEMS L or MEMS R header at the left edge
of the PCB. Ensure that the positive input of the speaker box (marked with +) is connected to the first pin of
a MEMS output connector (J12, J19, J14, or J20) as shown in Figure 5.
Figure 5: Connection of a Carme speaker box to the Helike 1.0 UA-E3010 PCB
Optional woofer
If desired, dynamic woofers can be connected to the woofer outputs. The built-in TI TPA2028-D1
amplifiers can drive speakers with a nominal impedance of 4 Ωor higher.
7.2. FOR DIONE MAXI UY-R3020
Dione Maxi UY-R3020 is a sound strip with 20 MEMS speakers and an external amplifier. The external
amplifier Amalthea 2.0 UA-R3020 that comes with Dione Maxi UY-R3020 must be used together with the
Helike 1.0 UA-E3010 development board because it offers a higher output power able to drive 20 MEMS
speakers.
7.2.1. DIP SWITCH SETTINGS
To select the correct filter configuration for Dione Maxi UY-R3020, set the DIP switches S1-1 through S1-4,
as shown in Table 6. This ensures that the correct filter coefficients are loaded into the audio pipeline.

14
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7.2.2. SPEAKER ATTACHMENT
Dione Maxi UY-R3020 sound strip
The Amalthea 2.0 UA-R3020 amplifier requires a single-ended input with an input amplitude of 625 mVrms.
This output is provided on connector J16 (right channel on Pin 2, left channel on pin 3). Additionally,
Amalthea 2.0 UA-R3020 requires a supply voltage of 30-36 V. This can be provided by
Helike 1.0 UA-E3010 via the same J16 connector. Note that in this case, supplying Helike 1.0 UA-E3010
with the external 36 V supply is mandatory. The connection diagram of Helike 1.0 UA-E3010 in conjunction
with Amalthea 2.0 UA-R3020 and Dione Maxi UY-R3020, is shown in Figure 6.
Figure 6: Helike 1.0 UA-E3010 and Dione Maxi UY-R3020 connections
Optional woofer
If desired, electrodynamic woofers can be connected to the woofer outputs. The built-in TI TPA2028-D1
amplifiers can drive speakers with a nominal impedance of 4 Ωor higher.
7.3. FOR DIONE MINI UY-R3010
Dione Mini UY-R3010 is a sound strip with 15 MEMS speakers in 3 segments with built-in amplifiers. It
needs to be supplied with 5 V and requires a balanced input signal. The supply and input signal are
provided by the Helike 1.0 UA-E3010 PCB on the Dione Mini UY-R3010 connectors (J15, J23). One
segment has a max. current consumption of 900 mA at a signal frequency of 20 kHz.
7.3.1. DIP SWITCH SETTINGS
To select the correct filter configuration for Dione Mini UY-R3010, set the DIP switches S1-1 through S1-4,
as shown in Table 6. This ensures that the correct filter coefficients are loaded into the audio pipeline.
7.3.2. SPEAKER ATTACHMENT
Dione Mini UY-R3010 sound strip
The Dione Mini UY-R3010 requires a balanced input with an input amplitude of 620 mVrms. This output is
provided on connectors J15 (right channel) and J23 (left channel). Additionally, Dione Mini UY-R3010
requires a supply voltage of 5 V. This can be provided by Helike 1.0 UA-E3010 via the same connectors.
Note that in this case, supplying Helike 1.0 UA-E3010 with the external 5 V supply is mandatory. The
connection diagram of Helike 1.0 UA-E3010 in conjunction with Dione Mini UY-R3010 is shown in Figure 7.

15
Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
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Figure 7: Helike 1.0 UA-E3010 and Dione Mini UY-R3010 connections
Optional woofer
If desired, electrodynamic woofers can be connected to the woofer outputs. The built-in TI TPA2028-D1
amplifiers can drive speakers with a nominal impedance of 4 Ωor higher.
7.4. FOR DANUBE 5.0 UAM-P2050
Danube 5.0 UAM-P2050 is an audio module that includes a MEMS speaker and a woofer for eyewear
temples. It can be used in conjunction with Helike 1.0 UA-E3010, which provides amplified signals to the
drivers.
7.4.1. DIP SWITCH SETTINGS
To select the correct filter configuration for Danube 5.0 UAM-P2050, set the DIP switches S1-1 through
S1-4, as shown in Table 6. This ensures that the correct filter coefficients are loaded into the audio pipeline.

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Released in November 2020, updated in June 2022
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7.4.2. SPEAKER ATTACHMENT
Danube 5.0 UAM-P2050 requires two amplified signals, one for the MEMS speaker and one for the woofer.
Helike 1.0 UA-E3010 provides these signals on the jumpers J12, J14, J19, and J20 (MEMS), and on J11, J13,
J21, and J22 (woofer). The connection diagram is shown in Figure 8. If desired, up to four Danube 5.0 UAM-
P2050 can be connected to Helike 1.0 UA-E3010 simultaneously.
Figure 8: Danube 5.0 UAM-P2050 connections to Helike 1.0 UA-E3010
8. CREATING A HELIKE 1.0 UA-E3010 CONFIGURATION FILE
Precompiled configuration files for Helike 1.0 UA-E3010 can be downloaded from the public git repository
under https://github.com/usound-tech/audio_device_configuration. They contain the optimal settings for the
devices mentioned in Table 1 and can be selected via the DIP switches S1-1 through S1-4, as shown in
Table 6.
If an individual filter set is desired, it can be created by editing a .json file. One of the custom configuration
file slots can be used to store the configuration file (with an appropriate file name) and can be loaded by
Helike 1.0 UA-E3010 when selected via the DIP switches S1-1 through S1-4.
If the DIP switch setting is changed, Helike 1.0 UA-E3010 must be reset for the new filters to be loaded at
the startup. This can be achieved pressing the “reset” button or by unplugging and re-plugging
Helike 1.0 UA-E3010.
To generate a custom configuration file, proceed as follows:
8.1. CUSTOMIZE A HELIKE 1.0 .JSON FILE
The Helike 1.0 UA-E3010 acoustic response can be configured using .json files. A sample .json file can be
downloaded from the git repository (https://github.com/usound-tech/audio_device_configuration). The
structure of the file is shown in Figure 9. Four blocks are available to tune the acoustic response. The

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
master EQ and DRC processing is applied to the input signal. The crossover EQ is applied to each of the
outputs and is therefore ideal for filtering specific speaker signals, e.g., low-pass for the woofer outputs.
Figure 9: Helike 1.0 .json configuration file structure
To customize the acoustic response, download the sample.json file and open it in a text editor.
8.2. FILTER CONFIGURATION
The digital filters implemented in Helike 1.0 UA-E3010 are biquadratic filter functions. The filters use a
direct form I implementation and follow the difference equation:
y[n] = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2]
where the first three coefficients (b0, b1, and b2) represent the numerator coefficients (feedforward
coefficients), and the last two (a1 and a2) represent the denominator coefficients (feedback coefficients).
Some tools and literature designate coefficients a0, a1 and a2 as feedforward coefficients and b1 and b2 as
feedback coefficients. Make sure to cross-check the naming convention applied by your tool or literature.
Note also that some tools/literature use a negative sign in the difference equation for the feedback
coefficients. In this case, the feedback coefficients must be negated when copying them to the .json file.
Figure 10 shows the EqCoefficients section of the Helike 1.0 UA-E3010 configuration file. Eight filter
stages are available for configuration in each EQ block. To change the filter behavior, the coefficients for the
desired filter response need to be added in the .json file manually. Use a tool of your choice (e.g.,
https://www.earlevel.com/main/2013/10/13/biquad-calculator-v2/) to generate a set of biquad filter
coefficients and transfer them into the editor.

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
Figure 10: Filter coefficients in Helike 1.0 UA-E3010 .json file
The first three positions represent the numerator coefficients (feedforward coefficients, b0-b2), while the
last two positions represent the denominator coefficients (feedback coefficients, a1, a2). The same
sequence is used for the crossover coefficients. Note that the feedback coefficient a0 is assumed to be 1 in
this implementation. It cannot be changed and is therefore not listed in the configuration file.
An example of a custom filter implementation can be found in section 11.3.
8.3. DRC CONFIGURATION
Besides the filtering functions, a software dynamic range compressor is built into the Helike 1.0 UA-E3010
firmware. It consists of a leveler and a limiter that are both applied to the audio input signal.
To use this function, set the parameters “levelerDrcEnabled” and “limiterDrcEnabled” to true and configure
the settings as desired. The parameters of the DRC are shown in Figure 11, together with descriptions of
the used units.
Figure 11: Leveler and limiter settings

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
8.4. CONVERT .JSON FILE TO .BIN FILE
Helike 1.0 UA-E3010 reads filter configurations in .bin format from the MicroSD card. To convert the
created .json file to the .bin format a .json to .bson converter tool is available at https://github.com/usound-
tech/audio_device_configuration/tree/master/tools. To make a conversion with the tool, download and unzip
the files. You should now have two files in your extraction directory:
•JsonBsonConverter.exe
•MongoDB.Bson.dll
To execute the converter, follow these steps:
1. Open the Windows command line.
2. Navigate to the path where the JsonBsonConverter.exe file is located.
3. Start the JsonBsonConverter.exe by typing the file name and pressing enter. You should see the
tool responding with usage instructions, as shown in Figure 12.
Figure 12: Command line prompt when executing JsonBsonConverter.exe
4. To execute the script and convert a file, a .json input file and a .bson output file must be specified,
as shown in Figure 13. To do so, enter the command in the format
JsonBsonConverter.exe [input_file] [output file]
Take care to enter the in- and output file names in the same command line row.
Figure 13: Specifying input and output file in the JsonBsonConverter.exe tool
5. Hit enter to execute the command. The message “Operation successfully completed” should be
displayed.
As the last step the created .bson file must be converted to a .bin file. To do so, open the .bson file with a
text editor and save it with the file name corresponding to one of the custom filter slots (e.g., config-8.bin).
Alternatively, you can rename the file in your file browser.

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Helike 1.0 UA-E3010 | User manual
Released in November 2020, updated in June 2022
USound GmbH | www.usound.com | [email protected]
Note: Should the .bson/.bin file have a file size of 0 bytes, likely an error has occurred in the conversion.
Review the format of the .json file for missing brackets or incorrect punctuation and repeat the conversion
step.
8.5. PLACE FILE ON MICROSD CARD AND SET DIP SWITCHES
Copy the generated .bin file into the /usound/ folder on the MicroSD card. Name the file config-X where X is
the desired configuration number that needs to be selected by the DIP switches. The filters and DRC
configuration will be loaded at the next startup of Helike 1.0 UA-E3010.
9. INTERFACES
9.1. JOYSTICK
Helike 1.0 UA-E3010 offers a built-in joystick (SW2) that can be used to control the volume and the
playback of files in SD card input mode. Figure 14 shows the joystick and its functions.
In USB input mode, the joystick is deactivated and does not offer any functionality. In I2S input mode, the
joystick can be used to adjust the output volume.
Figure 14: Joystick operation in SD card input mode
Play/Pause
(SD-card mode) Next track
(SD-card mode)
Volume up
Volume down