Hello, in my house, instead of using switches, I've placed buttons in each room, and a central electrical box filled with relays. This allows me to control each room's light from a central place, and gives me some flexibility. What I would like to do now is to drive these relays using Arduino, and the problem is: how can I "read" the relay state, considering that it could be "on" or "off" (they are latching (bistable) relays)?
The ideas that I've already discarded are: - use a transformer and a rectifier for each relay; - use a second relay, with 220v coil, for each relay.
Have you ever done something like this? Ideas?