File Exchange Pick of the Week

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Intruder Alert! 5

Posted by Jiro Doke,

Jiro's pick this week is Intruder Detection by David Leffingwell, a fellow MathWorker.

I really like examples that involve hardware because they are flashy and you can physically see things happening. The MathWorks
provides several toolboxes for connecting to various types of hardware, ranging from data and image acquisition boards to
stand alone instruments.

What I like about this nifty demo is that it combines both Data Acquisition Toolbox and Image Acquisition Toolbox to do motion and noise detection. Once the program detects some motion or noise, it starts recording video and audio for
a specified number of seconds. It's also very simple to try out, because it only requires an off-the-shelf webcam (I'm using
a Logitech USB webcam) and a soundcard which is already installed on my laptop.

Take a look at this short recording I made. I tested this out at a hotel in Kalamazoo, MI (I was there for a seminar).


Anybody doing hardware interfaces? Tell me about it here. I would be interested in hearing about simple examples that you can do with a webcam or a sound card (so that I can try
it out!). And please post them on the File Exchange!

Get the MATLAB code

Published with MATLAB® 7.6


Comments are closed.

5 CommentsOldest to Newest

Mahmood replied on : 1 of 5

Hi there,
when I run this program application, it gives me the following error

??? Error using ==> wavread
Index range must be specified as a scalar or 2-element vector.
Error in ==> intruderdetection>customAlarmData at 175
[data, frequency, nbits] = wavread(‘alarm.wav’,’double’);
Error in ==> intruderdetection at 140
[alarmData, frequency, nbits] = customAlarmData();

Can you please help me out fixing the problem

jiro replied on : 2 of 5


It’s probably best to ask the author of the tool for specific questions regarding the application.

But here’s some advice for debugging m-files. Notice the error message you are getting. It’s basically saying that there’s an error in line 175 with the “wavread” function. Type “help wavread” to make sure that the syntax is valid. In this particular case, it’s possible that you are using an older version of MATLAB, which may not support the particular syntax. You may be able to just remove the ‘double’ argument and make it work. Give that a try.

Girish replied on : 4 of 5

I am using R2006a version.Is it possible to do motion and nosie detection in my laptop? what else i reqired for motion ad noise detection?

Thank You,