Using the ACS712 as a DC current measure connected to a PIC16F819

[Khallos]

Hi all,

At the moment I am trying to connect the ACS712 to a PIC16F819 to give me a value for the current flowing in my curcuit. It is a simple circuit with 1 resistor and 1 variable resistor. The current when measured with a DMM is 1- ~0 mA. The output of the ACS712 however stays constant at 2.49V. I used the set up as drawn on the first page of the data sheet. any help on how to get this to work would be appriciated.

Many thanks.

Khallos

[Acetronics2]

Hi all,

At the moment I am trying to connect the ACS712 to a PIC16F819 .... The current when measured with a DMM is 1- ~0 mA. The output of the ACS712 however stays constant at 2.49V. I used the set up as drawn on the first page of the data sheet. any help on how to get this to work would be appriciated

Khallos

are you serious ???

5.0 V, single supply operation
66 to 185 mV/A output sensitivity
Output voltage proportional to AC or DC currents

AND

Output.pdf


Alain

[HenrikOlsson]

Hi,
Are you saying that the current is between 0 and 1mA? If so I'd say that explains it since the sensitivity of the sensor, for the X05B version of the ACS712, is 185mV/A nominally which for 1mA means an change in output voltage of 185uV.

If you're saing that the current is from 0 to 1A then you should see the output voltage of the sensor change from the 2.5V nominal to 2.685V OR 2.315V depending on the direction of current flow.

If you have the X20 or X30 version the sensitivity is even lower at 100 and 66mV/A repectively.

/Henrik.

EDIT:Alain beat me to it....

[Acetronics2]

Good reading ...
http://www.picbasic.co.uk/forum/showthread.php?t=11545

Alain