labview arduino allegro current sensor

[arios85]

Hello,

I am trying to read current through my load. Basically I have a buck converter with a P channel mosfet. This mosfet is controlled by a high switching opto coupler. This optocoupler is attached to the arduino. Arduino is being controlled through labview. I have everything done ( circuit built, everything talking to one another, voltage at my output through a voltage divider, etc.) aLl I would like to do is measure current at my load. i have a allegro acs 712. I already calibrated it, (meaning did the linear fit equation), but cant get it to read across my load. I put  Ip+ to through one end of my load and Ip- to the other end which goes to ground. the 5v pin on the sensor goes to 5 v on the arduino. Ground goes to ground. Vo on the sensor goes to my analog port 5 on my arduino. I am simply trying to read the current, but I am only get 5 volts at my graph. So i am picking up a voltage but its from the arduino and not my load. Do I need to convert this voltage through the linear fit equation I did for the sensor in order to have it convert to current?? has anyone does this sort of example before? I can send code if someone wants. Thanks so much

paul

[johnsold]

paul,

I have used other Allegro Hall effect sensors quite successfully.

Your terminology has me wondering if you have the current sensor connected correctly.  The Ip terminals connect in series with the load, not across it. If you have the Ip terminals in parallel with the load, you have shorted out your buck converter.  The 5 V output may correctly indicate the overranc ge short circuit current.  Can you post a .png image of your circuit schematic?

At zero current you should get 2.5 V at the output of the sensor.

Lynn

[arios85]

[arios85]

Lynn,

Thanks for your response. Yeah I am sorry about the incorrect usage of words. I meant to say in series with my load. my load through hole 10W 24 R resistor goes to ip+ and ip- goes to ground. for the code in labview,, as you can see all im doing is putting an analog read comand and attaching a wave form at my output. do I need anything else>??? thanks for yours and anyone else's time.

does everything else seem to be connected right? 5 v going to 5v on the arduino. V0 going to A05 in arduino. ground to ground?

paul

[whatsap45]

I had the same connection and it does not give any reading from the current sensor where 2.5v is expected to be read. 

[johnsold]

Did you verify that you have power and ground on the appropriate pins of the sensor? When you say "does not give any reading...", exactly what do you see? Zero volts is a reading, just not what you expect. "does not give any reading..." tends to mkae me think that your voltmeter turns off when you connect it to the output!

Are you referring to a voltmeter reading or the output of the Arduino?

What tests have you done to isolate the problem?

Lynn

[whatsap45]

https://decibel.ni.com/content/thread/21527

Similar question I have posted, but in detailed...

[whatsap45]

It gives 0.00, but 2.5v is the expected value from the current sensor ACS712.

[vmohadeb]

I am trying to do the same thing.

What did you write for your Arduino program?

Do you still have the labview VI?

[Chantastic!]

Hi Vmohadeb, you would probably be better off making a new topic. The last post in this one was almost two years ago, if you're having problems a new board post would probably get more attention.