Detecting device/bulb/socket state without using ACS217

arduinohome-automation

I am planning to do home automation using Arduino.

It includes a manual switch and can be also controlled by Arduino.

My problem is I want know the status of the bulb/device or socket. Recently I learned about the ACS217, the problem with ACS is it can measure very large current more than 1 amp.

So I came up with the design below. Should I go ahead with this or are there better solutions?

Schematic

Best Answer

Use a NPN optocoupler instead of a LED and a LDR. You'll find it easier to work with since you can treat it as a normal transistor and put it between ground and an input with its pullup enabled.