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

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

[Atiqah Selamat]

hi

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

tq

Answer 1

[Manisha]

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

[HARITHA]

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

[Atiqah Selamat]

i am using this code but do not how to check where it did save my recording.

Answer 2

[Vinh Dang]

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?