ftp://imall.iteadstudio.com/IM120417022_ISShield/DS_IM120417022_ISShield.pdf
I am using this relay shield's sensor interface pins and I had things working fine then things went south the 5v in gone on the pins by the sensor interface.... the middle pins, what I am doing is connecting the signal pin to the 5v pin then a 10kohm resistor from the signal pin to ground.....