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HARITHA
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USING DAQ TOOLBOX TO ACQUIRE MICROPHONE ARRAY DATA USING NI USB 9234

Asked by HARITHA
on 10 Feb 2012
Latest activity Answered by Vinh Dang on 5 Mar 2015
Hello,
I am trying to use DAQ toolbox to measure microphone Array data using NI USB 9234.
In LabVIEW, I configure the device using sound pressure measurement mode.
But, I don't know how to do that in MATLAB DAQ toolbox.
My code is:
clc;
clear all;
i=0;
ai=analoginput('nidaq','Dev1');
chan=addchannel(ai,1);
set (ai, 'SampleRate', 1700);
set(ai.Channel, 'UnitsRange', [0 135]); /* tried it in both volts range and db range*/
set(ai.Channel, 'Units', 'dB');
set(ai,'SamplesPerTrigger',inf);
%%start acquisition
start(ai);
while isrunning(ai)
[data,time]=getdata(ai,1);
i=i+1;
data1(i,1)=data;
end
stop(ai);
Data that's being saved seems to contain only noise. I don't see any sound data i it.
It would be great if someone could tell me how to acquire sound data using the toolbox.
Thanks, Haritha

  1 Comment

hi
how you take out data from your recording? I also have problem with that
tq

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2 Answers

Answer by Manisha
on 13 Feb 2012

Hi Haritha,
NI 9234 has built-in IEPE excitation circuitry. Is your microphone IEPE compliant?
If yes, you can use the new feature added in session based interface for your microphone. R2012a pre-release has added a new specialized measurement type called 'Microphone'. This will turn on the IEPE excitation on your device and thus return meaningful results
You may need to modify the following code:
s = daq.createSession('ni');
s.addAnalogInputChannel('Dev1', 0, 'Microphone');
s.Channels.Sensitivity = 0.037; %Set the microphone's Sensitivity to the value specified in the sensor's data sheet in v/Pascals.
[data,time] = s.startForeground();
Hope that helps,
Manisha

  2 Comments

Thanks a lot for your reply.
Yes, my microphone is IEPE compliant.
Can I do it with R2011b version of MATLAB which has version 3.0 DAQ toolbox?
Thanks,
Haritha
i am using this code but do not how to check where it did save my recording.

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Answer by Vinh Dang on 5 Mar 2015

Hello, In my application, I have a cDAQ configuration with AI modules 9234 (for accelerometers), 9237 (for pressure and load cell) and 9215 (for proximity and temperature). All modules are put in one chassis cDAQs-9178. What is the valid sampling rate for this?

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