530*1LSB @Vref=5V corresponds to 2.588V, wich corresponds to 4.395A...
I think that is the normal accuracy at that sensitivity...
have u read the datasheet regarding accuracy?
what happens when u use different currents?
like 1A, 2A, 0A, -1A, -2A?
the value for 0A seems to drift inspite of self-calibration on my ACS7xx-s...
r u sure that Vref is 5V?
did u get the current direction right?
there is IP**+** and IP**-**...
Amp = (512-analogRead (0))*vcc/1024/0.02-0.02
why do u subtract "-0.02" in ur formula?