acs712 current sensor

Other Hardware Sensors
1

I am trying to detect if a 100w 120v lamp is on or off using a sparkfun acs712 low current sensor and an arduino.

Does this schematic look right to you?
Just using a volt meter the change from off to on registers, but then the voltage will fall to the same as if it was off. I have experimented with vref and gain to try to stabilize the output but I haven't had any luck.

2

Did you perform the calibration as suggested on the product page at Sparkfun ?

Did you also read the comments about possibly removing the gain module ?

Craig