1062-107D Issue E published

NEDSP1062-KBD Operating ManualNEDSP1062-KBD Operating Manual

bhibhibhibhibhiNEDSP1062 KBD

Amplified Noise Eliminating DSP Module

Installation and Operating Manual

Sou

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hi

1062-107DIssue E

Page 40

bhi Ltd22 Woolven Close

Burgess HillWest Sussex

RH15 9RR

tel: +44 (0)845 217 9926fax: +44 (0)845 217 9936

[email protected]

bhibhibhibhibhiS

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En

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DSP Noise Cancellation


Copyright

This publication, including all photographs andillustrations is protected under internationalcopyright laws, with all rights reserved. Neitherthis manual, nor any of the material within, maybe copied or reproduced without the writtenconsent of bhi Ltd.

Disclaimer

The information in this document is subject tochange without notice. bhi Ltd. makes norepresentations or warranties with respect to thecontents hereof and specifically disclaims anyimplied warranties of merchantability or fitness forany particular purpose. Furthermore, bhi Ltd.reserves the right to revise this publication and tomake changes from time to time in the contenthereof without obligation of bhi Ltd. to notify anyperson of such revision or changes.

Important Information

Page 39

8.3 NEIM1031 In-line module.Then NEIM1031 provides a flexible solution to noise reduction. Itfeatures both amplified inputs and outputs, along with line level sig-nal processing. The unit also features an audio bypass when theunit is switched off, so there is no need to disconnect when not inuse.

Features:• Fully adaptive noise cancellation 9 -35dB

• 8 user selectable noise cancellation levels

• Mono earpiece socket

• Input sensitivity control

• Noise cancellation On/Off switch

• Line level in/out

• Input overload indication

• Power on/off with audio bypass.

8.4 NEIM1031 accessories.

8.5 DSP modules.

LSPKR20 Watt extension speakerfor use with the NEIM1031.Fitted with a 3.5mm monojack plug.

1031-STAMounting stand for the NEIM1031.Allows the NEIM1031 to be ad-justed for the most comfortableoperating postion.

8.O

ther

bh

i pro

du

cts.

DSP module range.NEDSP1061: Low signal level moduleNEDSP1062 - KBD: Low signal level module

controlled by single buttonkeyboard.

NEDSP1062 - KBD: Amplified DSP modulecontrolled by a 2 buttonkeyboard.

1030-UKPA UK DC power adapter1030-EUPA European DC power adapter


1. Introduction1.1 NEDSP1062-KBD features 51.2 Limitations 51.3 Module connection and mounting 61.4 Keyboard mounting 71.5 Sounder mounting 81.6 DSP noise cancellation 9

2. Module description2.1 Block diagram 102.2 Module layout 112.3 Pin functions 112.4 Controls 12

2.4.1 PCB controls 122.4.2 Keyboard 12

2.5 Electrical characteristics 12

3. Installation3.1 Installation overview 163.2 Module setup 17

3.2.1 Overview 173.2.2 Suggested set up procedure 173.2.3 Changes to output load 183.2.4 Other signal considerations 18

3.3 Driving the module from a low level signal 19

4. Functions4.1 Keyboard 20

4.1.1 Power button 204.1.2 DSP level button 20

4.2 Set up 214.3 Demonstration modes 234.4 Noise cancellation levels 24

5. Application notes5.1 Yaesu SP8 255.2 Kenwood SP31 285.3 bhi label 31

Contents

Page 38

8. Other bhi productsOther noise cancellation products from bhi. Visit www.bhi-ltd.co.ukfor more information.

DSP noise cancellation built into a compactspeaker unit. the unit provides an easy toinstall solution to noise reduction

Features:• Fully adaptive noise cancellation 9 -35dB

• 8 user selectable noise cancellation levels

• Mono earpiece socket

• Input sensitivity control

• Noise cancellation On/Off switch

• LED indication of power and noise cancellation

• 12-24VDC operation

• On/Off audio bypass switch.

• Greatly improved signal to noise ratio

• Easy to install with adjustable mounting bracket

• 2m audio lead

• Optional extras avaiable.

8.1 NES10-2 MKII Noise Eliminating speaker.

Basic plug and go noise cancellingspeaker preset to 20dB of noisereduction.

Features:• Fully adaptive noise cancellation 20dB

• 12-24VDC operation

• Compact robust speaker unit.

• Greatly improved signal to noise ratio

• Easy to install with adjustable mounting bracket

• 2m audio lead

8.2 NES5 Noise Eliminating speaker.

8.O

ther

bh

i pro

du

cts.


6. Physical dimensions6.1 Physical dimensions 326.2 Keyboard hole drilling detail 35

7. TroubleshootingTroubleshooting 37

8. Other bhi productsOther bhi products 38

Page 37

Sta

rt

Incr

ease

input

leve

l

Ove

r lo

ad L

ED

illum

inate

s? N

o

Yes

Reduce

input

so L

ED

goes

out

Incr

ease

outp

ut

leve

l P1

Suffic

ient

outp

ut vo

lum

e?

Supply

volta

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<13.8

Vdc

Input le

vel

too lo

w

Incr

ease

supply

volta

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Fin

ish Y

es

Dis

connect

R6

(see s

ect

ion 3

.3)

Ove

r lo

ad L

ED

illum

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s?

Add a

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onal

am

plif

icatio

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No

Yes

No

No

Yes

7.2

Insu

ffuci

ent

outp

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lum

e

7. Troubleshooting

Input

signal

Ove

rload

LE

D o

nR

educe

input

leve

l

Incr

ease

outp

ut le

vel

P1

Apply

audio

sig

nal

Incr

ease

input

signal

P2 N

o

Yes

No

Yes A

udio

out?

Fin

ish

Sta

rt Yes

No

7.1

No

audi

o ou

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7.Tr

ou

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sho

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.


1. Introduction.The NEDSP1061-KBD is a modular solution for noisereduction. It incorporates Digital Signal Processing (DSP)technology to provide up to 35dB of noise cancellationand 65dB of tone reduction. The module features an onboard power amplifier to allow it to be easily incorporatedin to existing equipment by installing the module in linewith the loudspeaker. All functions of the module arecontrolled by an easy to use keyboard.

1.1 NEDSP1062-KBD module features:

Fully adaptive noise cancellation up to 35dBInput and output level controlsInput level over load indicationVirtually no distortion to speech signalEasy to install4/8 levels of noise reduction (selectable)Frequency response 50Hz - 4.3KHz3 Watts output (4W)Single button operation of DSP mode with LED andaudible indication12 - 18V supply range27dB on board gainPower on/off - bypass pushbuttonSmall size 37 x 50mm (DSP pcb)Audio bypassed when power disconnectedSupplied with fixing and wiring kit and all labels

1.2 Limitations.This module is designed to pass speech. Other signalssuch as data, music and morse (CW) will to some degreepass through, but the integrity of these signalscannot be guaranteed. 1.

Intr

od

uct

ion

.

Page 36

<This page is intentionaly blank>


Figure 1. Mounting options

1.3 Module connection and mounting

The module is supplied with a pre-wired 2.1mm powerconnector. The centre pin is positive. The audio in andout are pre-wired pairs of wires, ready to be connectedin the audio path. The heatsink doubles up as a mountingbracket.

This module is designed to be driven from a high levelsignal, capable of driving a load of 22W.

(The module can be easily modified to be driven from alow power signal, see section 3.3 for more information).

The module can be mountedusing the supplied self adhesivefoam pad. Ensure that none ofthe circuit pins can make contactwith any metallic parts.

For improved heat dissipationand a more rigid mechanicalfixing the heatsink can bereversed and used as a bracket.Note that the heatsink is at 0Vpotential and therefore may have

to be electrically insulated from any other metallic parts.

Alternatively the module has fourfixing holes which allow it to befixed to pillars.(See section 6 for hole detailsand physical dimensions).

1.In

tro

du

ctio

n. Using the heatsink

as bracket

Self adhesivepad

Mounting usingPCB pillars

Page 35

6.P

hys

ical

dim

ensi

on

s.

6.2 Template.

The following drawing shows the sizes and positions ofholes for the keyboard.

Figure 36. Keyboard drilling detail .

Not to scaleall dimensions in mm

29.8

18.5

13.4

6.7

6.7

10.9

5.5

4mm4mm 4mm

3mm CSKto 5mm


1.In

tro

du

ctio

n.

If the installation has limitedspace, and is housed in a metalenclosure, the heatsink can beremoved, and the modulemounted directly on the chassis.The voltage regulator needs to becorrectly insulated as the tab isconnected to 0V. Insulate boththe regulator and mountingscrew. For improved heatdissipation use a suitable thermalpaste between the power devicesand the mounting.

Figure 2.Direct mounting.

Figure 3. Keyboard mounting 1.

The keyboard ismounted through theenclosure to providean easy to useinterface. Themodule is suppliedwith a label to placeover the keyboard.

When the enclosure is thick enough the keyboard isretained using a countersunk screw (supplied), which ishidden by the label, see figure 3 above. Do not overtighten the mounting screw.

keyboard

Front panellabel

Retainingscrew

Frontpanel

Insulator

Insulator

VoltageRegulator

1.4 Keyboard mounting.

(not supplied)

(not supplied)

Page 34

6.P

hys

ical

dim

ensi

on

s.

Figure 34. Keyboard dimensions.

Figure 35. Power connector hole size.

29.8

25.3

20.2

13.4

6.89.5

4.7

7.5

3.2

10

.9

5.53

8mm diameter


Figure 4.Keyboard mounting 2.

If the enclosure is toothin to incorporate acountersunk screw(such as fitting intosheet metal) then it canbe retained by ainstrument headscrew.The label needs to becut out to allow thescrew to pass throughfrom the outside. Thiscan be easily achievedby applying the label tothe panel, then carefully cutting around the screw hole,with a sharp knife. Again do not over tighten the screw.

Nut &washer

Front panellabel

keyboard

Retainingscrew

Frontpanel

1.5 Sounder mounting.

Cut a small piece of theself adhesive foam(supplied) to mount thesounder.Do not cover the smallhole in the face of thesounder.For best results mountthe sounder where itcan radiate sound tothe outside the case,for example on an airvent.

Figure 5. Sounder mounting

SounderBacking paper

Backingpaper

Self adhesivefoam

Case

Keep thishole clear

Cut holefor screw

1.In

tro

du

ctio

n.

Page 33

6.P

hys

ical

dim

ensi

on

s.Components fitted torear of PCB

Figure 32. Overall dimensions.

Figure 33. Hole dimensions of power devices - for directmounting applications.

16.1

5.3

17.9

16.4

Viewed fromthe end ofthe module

34.2

64.4

5.8


1.6 DSP Noise cancellation.

The bhi DSP processes the incoming signal and thendifferentiates the speech from the noise. The unwantednoise and interference is then attenuated to leave onlythe speech. The following diagrams are taken from actualaudio signals and illustrate how the signal is beingprocessed.

Figure 6. Noise cancellation.

Original signal.Speech with a lot ofbackground noise

Processed speech.Speech with reduced

noise

Speech Noise Reduced noise

1.In

tro

du

ctio

n.

Page 32

23.4

2.97

30.3

34.3

36.5

49.6

2.97Pin 1

3mm dia

6.P

hys

ical

dim

ensi

on

s. 6. Physical Dimensions

Figure 31. Mounting hole positions.

Top

6.1 Physical dimensions.The following diagrams detail the physical dimensionsof the module. All dimensions are in mm.


2. Module description.

Figure 7. NEDSP1062-KBD block diagram

1

3

8

Polarityprotection

Internalpull up

resistors

Input levelset

In 9

overloaddetect

Digital to analogueconversion

Output levelset

Power Amp

BCD DSP level select

Xtal

Clock generator

DSP core

5V5VRegulator

Latch

12V regulator

3.3V regulator

3.3V 12VRelayDrive

Relay 1

ON 14

Analogue to Digital conversion

70V

10

12

6

Power supplysection

PCBConnections

13

5

J3

InputLoad

resistor

Agnd

Agnd

Vin

NC

NO

NO

NCDSP

3V3 0V

PCB

microcontroller4

Keyboardinterface

8

N/C

N/C

Relay 1 Out

11

2.1 Block diagram.

2.M

od

ule

des

crip

tio

n.

Page 31

Figure 30. bhi label.

5.A

pp

licat

ion

s.

5.3 bhi Label.

Supplied with the module is a square bhi label. Fix thelabel on the top of the speaker enclosure as shown.

bhibhibhibhibhiDSP

NoiseCancellation


2.2 Module Layout.

The following diagram shows the layout of theNEDSP1062-KBD module.

Pin No. Name Description Notes

4 N/C Do not connect Not used

5 Vin Supply voltage 12 - 18VDC power in

6 N/C Do not connect Not used

7 0V 0V connection 0V power connections

9 In Audio input Audio signal in to be processed

10 Out Audio output Procesed audio signal out

11 Agnd 0V for input audio signal Analogue ground for audio in

12 Agnd 0V for output audio signal Analogue ground for audio out

Table 1. NEDSP1062 connection functions 2.M

od

ule

des

crip

tio

n.

Figure 8. NEDSP1062-KBD connections and controls

Inputlevel set

(P2)

Outputlevel set (P1)

Input overloadindicator LED

Mountingholes

Audiobypassrelay

The following table gives a description of the pin functions.

Note:Wiring obmitted for clarity

Soundervolume (P3)

2.3 Pin functions.

Page 30

Figure 29. Photograph of complete installation.

Sounder

NEDSP module(screwed to the case,using an existing hole)

Inputselectorswitch

FilterPCB

DSPconnections

Keyboard

5.A

pp

licat

ion

s.


2.4 Controls.

2.4.1PCB.The level controls provide adjustment for the audio levelsentering and leaving the module. The modules are factoryset to the maximum level.

Turning the potentiometers clock wise will decrease thelevels. These potentiometers do not have end stops, soit is possible to set them in a position where the audiowill be lost.

Audible indication of operation is provided by an piezosounder. The volume of this sounder can be varied bypotentiometer P3. The sounder volume is independentof the incoming audio volume.

2.4.2Keyboard.

The keyboard controls all of the module functionsincluding power on/off.

2.M

od

ule

des

crip

tio

n.

Figure 9. NEDSP1062-KBD keyboard.

Power button(power and

Audio bypass)

DSP levelbutton

Tri colourLED

Mounting hole

Page 29

5.A

pp

licat

ion

s.

NE

DS

P1

06

2

Lin

e o

ut

Input

Sele

ctor

Input

PC

B

Pow

er

Re

d

White

Bla

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Bro

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0V

Headphones

Filt

er

Blu

e

Bla

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Lin

e o

ut

Keyb

oard

Ye

llow

Ye

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43

125

12

3

12

21

43

Bla

ckB

lack

9 11

10

12

Connect

ions

to

module

Bla

ck

Re

d

Blu

eR

ed

Figure 28. Circuit diagram of installation in KenwoodSP31.

The

mod

ule

is in

sert

ed in

to t

he c

ircui

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the

filt

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CB

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ED

SP

1062

-KB

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nput

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B a

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the

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The

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the

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ount

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2.5 Electrical characteristics.

Symbol Parameter Test Conditions Min. Typ. Max. Units

Vs

Supply voltage 12 16 18 V

Iqs

Quiescent currentV

s = 12V

Vs = 16V

Vs = 18V

4.66.87.1

mA

Iqon

Quiescent current DSP onno load no signal

Vs = 12V

Vs = 16V

Vs = 18V

143160161

mA

ELECTRICAL CHARACTERISTICS(V

s=16V, T

amb= 25

iiiiiC unless otherwise stated)

DC CHARACTERISTICS

AC CHARACTERISTICSSymbol Parameter Test Conditions Min. Typ. Max. Units

Po

Output power

d = 10%f = 1KHz

RL = 8W

RL = 4W

12V

1.161.7

16V 18V

2.063.17

Vs

WW

Vi

Input sensitivty4W load

f = 1KHzP

O = 0.5W

PO = 1.0W

PO = 2.0W

6090130

mV

Vi

Input sensitivty8W load

f = 1KHzP

O = 0.5W

PO = 1.0W

PO = 2.0W

81117180

mV

BFrequency response(-3dB)

Po = 1W

RL = 8W

50 4300 Hz

d Distortionf = 1KHzP

O = 0.2 - 2.4W R

L= 8W

PO = 0.2 - 2.4W R

L= 4W

0.80.8

%

Ri

Input resistance 21 22 23 W

Gv

Voltage gain f = 1KHz 27 dB

n Efficiencyf = 1KHzP

O = 3W R

L = 4W

PO = 2W R

L = 8W

3338

%

ANALOGUE CHARACTERISTICSSymbol Parameter Test Conditions Min Typ Max. Units

Td

System delay 26 mS

2.M

od

ule

des

crip

tio

n.

Table 2. Electrical characteristics 1

Page 28

5.A

pp

licat

ion

s.DSP

Keyboard5.2 Kenwood SP31.

Figure 25. NEDSP1062-KBD installed in a KenwoodSP31.

This sectiondescribes the generalfitting of theNEDSP1062-KBDmodule in theKenwood SP31loudspeaker. Thisinstallation retains theoperation of theinternal filters.

Figure 26. Suggestedlocation of keyboard.

Figure 27. Suggestedlocation of powerconnector.

Suggested location formounting the powerconnector

This photographshows thesuggested locationfor mounting thekeyboard.


-20

-15

-10

-5

0

5

0 1000 2000 3000 4000 5000 6000

Figure 10. Frequency response

Frequency (Hz)

Out

put (

dB)

0

2

4

6

8

10

12

0 0.5 1 1.5 2 2.5 3 3.5

Figure 11. Distortion vs. Output power

Dis

tort

ion

Output power (W)

VS = 16V

f = 1KHz RL = 8W

RL = 4W

2.M

od

ule

des

crip

tio

n.

RL = 8W

VS = 16V

P = 1W

-3dB

Page 27

Figure 24. Complete installation in the Yaesu SP8.

DSPmodule

InputPCB

Powerconnector

5.A

pp

licat

ion

s.


Figure 12. Sensitivity.

0

0.5

1

1.5

2

2.5

0 50 100 150 200

Input voltage (mV)

Out

put p

ower

(W

)

RL = 8W

RL = 4W

VS = 16V

f = 1KHz

2.M

od

ule

des

crip

tio

n.

Page 26

Figure 23. Circuit diagram of installation in Yaesu SP8.5.A

pp

licat

ion

s.

NE

DS

P1

06

2F

ilte

r u

nit

Sw

itch

un

itP

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jack

unit

12

Bla

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Re

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122 1

Ke

ybo

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connect

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9 11

12

10

Connect

ions

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mo

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JP2

00

2JP

30

01

Re

dB

lue

The

NE

DS

P10

62 m

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n is

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ter

unit

and

the

phon

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Loca

te th

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wire

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and

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and

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Figure 13. Basic connection diagram

3.1 Installation overview.

The NEDSP1062-KBD module is inserted into the pathof noisy audio. The input and output level controls allowthe module to be fine tuned to suit most applications.

3. Installation

Audio in

Power amp

+

-

Break Circuithere

Audio Out(Loudspeaker)

The input to the module is loaded at 22W to provide adummy load to the preceding circuit. This can be removedif required, such as using the module in applicationswhere the audio source is provided by a low level, lowpower signal source. More information on this can befound in section 3.3 in this operating manual.

If Vin is less than approx. 13.8V ensure the power supply

is well decoupled otherwise the power supply rejectionratio will deteriorate. Best results are obtained in therange of 13.8V - 16Vdc.

Audio in

NEDSP1062Power amp

+

-

IN

Agnd Agnd

OUT

Keyboard

Power

10

12

9

11 Black

Piezosounder

BlueRed

Black

3.In

stal

lati

on

.

Page 25

5. Application Notes.

5.A

pp

licat

ion

s.

This section provides information into installing theNEDSP1062-KBD into Amateur radio speaker units.

Figure 20. NEDSP1062-KBDinstalled in a Yaesu SP8.

5.1 Yaesu SP8.This section describesthe general fitting ofthe NEDSP1062-KBDmodule in the YaesuSP8 loudspeaker. Thisinstallation retains theoperation of theinternal filters.

DSPKeyboard

Figure 21. Suggested location ofpower connector

Figure 22. Suggested locationof keyboard.

This photographshows thesuggested locationfor mounting thekeyboard.

Suggested location formounting the powerconnector


3.2 Module setup.

3.In

stal

lati

on

.3.2.2 Suggested set up procedure:

Basic setup procedure.Connect input source and output device.Ensure the NEDSP1062-KBD is switched off.Set the audio source to a typical audio level.Switch on the NEDSP1062-KBD.Adjust the input control (P2) until the overload LEDilluminates. Reduce the level by approx. 1/4 turn.Adjust the output level to the desired level.Hold down the DSP button and adjust the volume

of the sounder to suit using P3.

To obtain the best results from the noise reduction themodule should be set up to give optimum performance.The input sensitivity control has a range of 0.70mW -3W to provide 2W (W)output.

Under certain conditions, RF breakthrough cansometimes occur. To minimize this, the input level (P2)may need to be reduced or go to the FAQ page on thebhi website and download the FAQ on RF breakthrough.

Under certain conditions the DSP can create a smallamount of noise, normally when the unit has no signalapplied. You should not be able to hear this noise whena signal is applied.

Both the input and output levels are adjustable on themodule. This allows easy integration into the target system.

3.2.1 Overview.

Page 24

4.O

per

atio

n.

4.4 Noise reduction levels.

4 or 8 levels of noise reduction are available. The amountof noise and tone reduction is shown in the table below.

Level(4)

Level(8)

Tone Reduction White Noise Reduction

1 4dB 9dB

1 2 5dB 11dB

3 6dB 13dB

2 4 8dB 15dB

5 16dB 17dB

3 6 21dB 20dB

7 25dB 24dB

4 8 65dB 35dB

Table 4. Tone and noise reduction levels.

The column marked level (4) shows the noise and tonereduction when operating the module with 4 levels, andthe level (8) column for 8 levels.

Holding down the DSP select button will continuouslychange the DSP level. When the desired level has beenreached, release the button. The module will retain thislevel until it is changed.


The NEDSP1062-KBD requires a signal of 125mV rmsor greater for optimum performance. Signals lower thanthis may be used but the noise cancellation performancewill decrease, as the signal levels drops. If the unit isused with low level signals such as microphones, thesignal will need amplifying before applying it to theNEDSP1062-KBD.

Due to the adaptive nature of the noise cancellation asmall delay may be heard when the audio signalchanges. For optimum performance provide the modulewith a constant signal where possible.

When switching on the unit a thump may be heard in theloudspeaker.3.

Inst

alla

tio

n.

Figure 14. Input circuit -module powered down

22W

OUT

12Agnd

Agnd

9

10

V

AudioInput

NEDSP1062

R6

IN

Load

11

The audio input to themodule is loaded at22W. This load iseffectively connectedacross the output loadwhen the unit isswitched off(bypassed).This will reduce theimpedance presentedto the audio source.

For example:8W will reduce to 5.9W4W will reduce to 3.4W

3.2.3Change to output load.

3.2.4Other signal considerations.

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4.O

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Start

Noise cancellationOn

Wait 1.5 Seconds

Noise cancellation off

HighestLevel?

Normal operation

No

Yes

Increase DSPnoise cancellation

level

Start

Noise cancellation off

Noise cancellationOn

Wait 3 Seconds

No

Yes

DSP buttonpressed?

2 tone beep

Normal operation

Wait 3 Seconds

Demonstration 2.The module switchesthe noise cancellationon for 3 seconds thenoff for 3 seconds. Thisis a good demonstra-tion of the before andafter effects of remov-ing the noise.

Demonstration 1.The module switches thenoise cancellation on for 1.5seconds, then off for 1.5seconds. It will then move tothe next level and repeat theprocess.This mode is particularlyeffective at demonstrating thedifferent DSP levels.Alternatively pass a cleanaudio signal through themodule to see hear how littlethe DSP alters the speech.

Note:To exit the demonstra-tion modes hold downthe DSP button until a2 tone beep is heard.

Figure 19.Demonstrationmodes.

4.3 Demonstration modes.


Figure 16. Circuit modification for low power signal drive.

3.3 Driving from a low signal source.

The input to the module has a low impedance. This is toprovide correct loading to any power circuits driving it. Ifthe module needs to be driven from a low power signalthen it must be modified in the following manner.

Cut theleg on this

resistor

3.In

stal

lati

on

.

22W

OUT

12Agnd

Agnd

9

10

LoadV

AudioInput

NEDSP1062

R6

IN

11

Circuitmodification

Figure 15. Physical modification for low power signaldrive.

Note:Wiring

omitted forclarity.

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To listen to the demonstration modes, or change thenumber of DSP levels it is necessary to put the moduleinto the set up mode.

To do this, ensure the module is Off. Press and hold theDSP level button. Turn on the module and a 2 tonebeep will be heard indicating that the module is in theset up mode.

Releasing the button after the first 2 tone beep will enterdemonstration mode 1.

Releasing after the second 2 tone beep will enterdemonstration mode 2.

Keeping the button depressed with change the numberof levels available. 4 beeps will indicate 4 level modeand 8 beeps 8 levels. Release the button when thedesired level is reached.

The module will return to normal operation after this.The colour of the LED will indicate the mode of operation.

DSP mode 4 Levels 8 Levels

OFF RED ORANGE

ON GREEN GREEN

Table 3. LED mode indication.


4. Operation.4.

Op

erat

ion

.

4.1 Keyboard.The keyboard has 2 buttons and a tricolour LED.

4.1.1Power button.The power button switched the module on and off. Whenthe module is off, the audio bypasses the module, sothe circuit will behave as if the module isn’t present.Switching the power on routes the audio through themodule.

Note: If the power is on and the DSP is switched off, theaudio still passes through the DSP - but without any signalprocessing.A single press on the button switches on, and a singlepress will switch off. Also with the power connected andthe module switched off the circuit will still draw 6mA.

4.1.2DSP level button.This button is used to set the following:• DSP on/off• DSP level• 4 or 8 levels of noise cancellation• Demonstration modes

Figure 17. NEDSP1062-KBD keyboard.

Power button(power and

Audio bypass)

DSP levelbutton

Tri colourLED

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Power up

DSP buttonpressed

2 tone sound

DSP buttonpressed

2 tone sound

2 tone sound

Demonstration2

Demonstration1

No

Yes

No

Yes

No

Yes

DSP buttonpressed

DSP buttonpressed

2 tone sound

DSP buttonpressed

Change 4 or 8 levels

Normal operation

No

Yes beep numberof DSP levels

Yes No

DSP buttonpressed

Yes

No

4.O

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4.2 Set up.The following flow chart shows the functions of the DSPbutton.

Releasing the DSP buttonat this point the modulegoes in to demonstrationmode 1

Keep the button downuntil the desired levelhas been reached, thenrelease the button. Themodule will continouslyscroll through 4 and 8levels until the button isreleased.

Figure 18. 4/8 level setting.

Holding down the DSPbutton when switching oncauses the module to enterthe set up mode.

This is indicated by a 2tone beep.

Releasing the DSP buttonat this point the modulegoes in to demonstrationmode 2

1062-107D Issue E published

Documents

Transcript of 1062-107D Issue E published