How to use audio input of mydaq to interface a sensor voltage acquisition

[Davidson_D]

Hello Guys

I am using a NI myDAQ.

In my project I have to interface 4 MEMS pressure sensor whose output range is (0 to 1)V.

As there are only two AI channels in myDAQ (apart from DMM and Audio input). But I tried to use the stereo Audio input channels for acquiring data.

But it doesn't allow DC input and attenuates completely.

Is there any way I can use 4 channel input in myDAQ.

Any help is greatly appreciated... 

Cheers,

Davidson D

[Kristoff2 · Accepted solution]

Hey Davidson_D,

You should be able to read DC analog voltages using the Audio inputs.  Another option is to build a simple analog multiplexing circuit to switch between the inputs (for example you couldu use the 74HC4051).  You can control the mux using myDAQ digital outputs.

-Sam K

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[Davidson_D]

Thanks Sam.

I tried with Audio input by giving in a sine wave ranging from 1hz to 100 hz. I observed that only above 20Hz i get approximately actual amplitude i sent.

Below that the signal is not correct.

Is there any settings for audio input?

The switching idea is good one. I will try to implement that in my project. 🙂

Regards,

Davidson D