how to select input sound devices to acquire data in labview

[mehran-ne]

hello

i'm working with a radar sensor and its receiver connected to my laptop by microphone/headphone device. i want to acquire signals from that receiver. i tried using acquire sound in labview but it doesn't work. when i want to configure acquire sound , just microphone that is related to webcam appears and labview doesn't identify microphone input device that can acquire data from receiver. how can i fix this problem?

 special thanks

[Bob_Schor]

To acquire data from an external device, you need a hardware interface.  National Instruments got its start (and its name) building instruments for acquiring data from the outside world and presenting it to the PC for processing.

I assume that you do not have external hardware (such as an NI USB-6002) with an A/D converter, but do have a PC (or Mac) with a Sound Card having Microphone Inputs and Headphone Outputs.  Windows can access this hardware to input signals represented by voltages at the Microphone input (two channels), and LabVIEW has some VIs that tap into the Windows routines.  Look in the Graphics and Sound Palette.  Now all you need is a small Microphone Plug and some wires to connect it to your voltage source.

Bob Schor

[altenbach]

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@mehran-ne wrote:

i'm working with a radar sensor and its receiver connected to my laptop by microphone/headphone device.

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Does the sensor mimic a microphone and ouputs small AC signals in the typical audio range on the contact corresponding to the mic input or does it use a proprietary connector that just happen to look similar to a mic/headphone plug?

Do you have a link to a website or manual that described your device. Is this a scientific instrument or just some cheap device warning you of police radar, for example? Do you have a full description on the interface specifications? Did it come with software? (Make sure to link to a real technical page, not some bulk advertiser).

Many modern jacks on computers are muti-purpose and need to configure themselves when you first plug in a device. The computer might ask you what you just plugged it to correctly set things up internally (choices might be e.g.: headphone, headphone with mic, powered speakers, mic only, surround system, etc.). Do you get a dialog when you plug in your device? Do you get a dialog when you plug in headphones instead?

What is your OS? In windows there are control panels to setup the audio inputs and outputs.

[mehran-ne]

you are right .  for the next step we will provide ni-myrio daq device to data acquisition but now i just want to display raw signals on the screen like another sound recorder apps. i had been used graphics and sound pallets to acquire signals but when i configured acquire sound vi ,the input port that receiver cabled to it did not identify and just microphone which located near the webcam was identified ( microphone (realtek high definition audio)).

[mehran-ne]

yes its look like a microphone and the voltages corresponding  to the  signals are between 0.8 and -0.8  and its connector is a wire that similar to mic/headphone plug.

and also its a scientific instrument that will be operational in the future. for the first step we have to receive and display raw signals acquired by the sensor. there are many simple apps to this work but i want to do it in labview. 

and when i plug in either the device or headphone, i do not get any dialog .

[altenbach]

Again, at this point it is not a LabVIEW problem, but a windows problem. Does the jack work if you e.g. connect a headphone with mic or just a mic? Does your sound system have it's own proprietary audio control panel, e.g. in the system tray?

What do you get if you right-click the sound icon (volume control) in the lower right and do an "Open sound settings"? Have you tried the troubleshooting wizards?

You still have not given us the OS version.

[Bob_Schor]

What have you tried?  It took me about a minute to do the fairly brainless operation of wiring an Express VI for Sound Input to another Express VI for Sound Output (I dislike Express VIs, but for doing brainless "Proof-of-Principles", I don't have to think).  When I ran the VI and said "Test, test, test, test, test" to my Laptop, about a second later it said "Test, test, test, test, test" back at me.

Show us the VIs you've written.  Tell us about your environment.  You are either doing something horribly wrong, or possibly not doing anything, just waiting for us to do it for you.

Incidentally, I didn't "select" any input sound device, I just used the (Windows) default Device 0 (the only one showing, called "Microphone (High Definition Audio Input)".

Bob Schor

[altenbach]

Bob, windows has no way of identifying what was plugged into an analog jack if the jack is multipurpose (the back of the computer case might have separate inputs for various purposes (speakers, line in, line out, etc.), but he has a laptop.

My desktop does not have a built-in mic (most laptops do, nowadays). If I plug in my USB webcam, it will have a MIC. If I plug "something" into the jack at the front of the case, it immediately asks me what it is and only if I say MIC, Line in, or headset (not headphones!), windows will list it as input. Simple analog gadgets (speakers, headphones, mic, etc.) are NOT plug-n-play and there is no way for the computer to figure it out on it's own unless the computer has dedicated jacks for each type. These days they don't.

He would need to configure his laptop headset jack as a "line-in" device, and that might not even be possible, depending on the hardware.

To repeat, this is not a LabVIEW problem, but a [windows/computer hardware] problem. Here's what I see in Windows 10

[Bob_Schor]

Valid point!  Thanks for pointing this out to me.

BS

[mehran-ne]

you are right , i found out that the problem was  from my laptop(hardware) and when i test the VI in another system , it worked so it has been solved and the VI is operational. 

thanks a lot for your guidance

now there is another problem. new laptops have just one input to connect to either mic or headset and as you know two analog data transmitter have been located on the analog input stereo convertor. in this case one is corresponding to the transmitter and another for receiver(mic and headset)

how can i access to these channels separately?