how to enable 2 or more analog input pin in arduino uno labview simultaneously for voltage analysis?

[syedanas]

Hi everyone,

i am new to labview and using arduino uno board for measuring microwave analysis in my project. i want to measure the refflection coefficient by dividing two analog input received to arduino (Vref and Vin) to obtain so. problems come where i just can analyze only one analog input pin only. please, kindly helped to figure it out.i've try the others solution where i create two while loops for different analog pin. u can refer to my circuit in the attachment below.i really2 appreciate ur help, thank you.=)

    

[mknix]

Hi,

You mentionned "i've try the others solution where i create two while loops for different analog pin"

What was the first solution?

What is sure, is that you should avoid tunnel between two while loop. (i.e, the stop button of second loop shall be controlled by a local for example).

Also the calculation (reflection coefficient, return loss) shall be include in the while if you want the value to be updated continuously.

Did you try something simple like this, with only one loop? :

[syedanas]

hi mknix,

thanx a lot for helping me..i did not realize that we just need to connect the analog read in series only for analysing more than 1 voltage input.btw, i will try the circuit that u suggested with the real input voltage later..thanx again for helping me buddy..=)

[hrh1818]

The Arduino Uno only has one ADC.  Hence you can not read two analog signals simultaneously.  It takes about 100 micro seconds to do a conversion.  For a discussion on this topic see:

<http://arduino.cc/forum/index.php?action=printpage;topic=77715.0>

hrh1818

[hrh1818]

For simultaneous sampling of multple analog inputs you could use an IC with a SPI interface such as the following.

<http://www.linear.com/product/LTC2351-12>

hrh1818

[mknix]

interesting readings, thanks a lot hrh1818.

[santhosh40]

hello guys,

         i think i had this same type of problem but instant of analog pins and i would like to use digital pins, can anyone plz give me some example block diagrams which   IT SHOULD USES MORE THAN ONE DIGITAL PINS which it may input or output

[Kristoff2 · Accepted solution]

MKnix gave one solution.  The other would be to ues a single analog read port VI.  The analog read port VI reads all the analog pins as fast as it can (as hrh1818 mentioned there will be about 100 uS between reads due to the muxed ADC).  If you use two analog read pin vis in series in a loop (the other 'good' way to read two pins) you will have to wait for data to go from the arduino back to LV, from LV back to the arduino between the analog reads.  This latentcy will be in the 5 mS range so if you want to compare the two AIs at 'the same time' the read port options is much better.

-Sam K

LIFA Developer

[mknix]

Thanks a lot Sammy_K, Indeed, analog read port is much better.

[Kristoff2]

Happy to help.

-Sam K

LIFA Developer