So I can write the code to display 230VAC if the detected voltage is 3.5V at arduino analog input pins . Im I right sirs ?Do I need to include any diodes to prevent damages to arduino ? or just only two resistors enough ? And what if i use a smoothing capacitor inbetween the ground pin and the other side of the grounded resistor ( 100kOhm ) ?
and i assume i get about 10.5VDC after rectifying ) .
also, theres things called hall effect sensors you may want to look into, but i dont know if they would be appropriate for what you are trying to accomplish.