Problem with DC current measurement in a circuit with current sensor ACS712

[engr.waqas]

I am trying to interface hall effect current sensor ACS712 which can measure both AC&DC currents to a PIC microcontroller.The sensor is working fine in pure dc path e.g from a solar panel to battery.but when i measure dc current between a UPS and a battery its value fluctuates too much.But when i measure dc current in same path using multimeter it does not fluctuates.
Now if i have problem in PIC A\D then why it is working in pure dc path.
Datasheet of this sensor says that it gives 2.5 to 5 volt in one direction of current and gives 0 to 2.5 in opposite direction so it can measure both AC&DC.

 

[Tahmid]

Current sensor help

Hi,
At the PIC ADC input pins, place a 1k resistor between the pin and the signal and a 100nF capacitor from the pin to ground. This may help you. I've faced situations where the resistor and capacitor maybe required for a stable reading.
And also make sure the PIC is well decoupled.
Hope this helps.
Tahmid.