about RF Switch 433 Mhz


I have got a doubt, but I haven't found reply. I would like that someone could tell me the solution of my question. I have got an transmissor RF 433 Mhz connected in my Arduino (pin 10), and a receiver RF 433 Mhz connected in the same Arduino (pin 2).

My sketch is simple, but it works enough ok. I can open two lamps and a electrical appliance with my mobile phone. Until here, no problem.

Is it possible know if my switch RF is ON or OFF when I am not at home?

Sometimes, the signal RF doesn't arrive correctly and I don't know if my electrical appliance is run on or not when I am not at home.

I work with library RC-Switch. Too, I've "read" library "Remote Switch" but I haven't found anything. My know about programming aren't very high.

Is there some sketch or code, that I know real state of my devices. If they are ON or OFF.

Thank you very much!


This is a common problem and there is no 100% reliable solution. To start, you would need another sensor at the electrical appliance to report back to you whether the appliance is on or off. In the case of a lamp, you could use a light dependent resistor (LDR), but obviously, any sensor (as well as the lamp itself) can fail.

You can improve the odds of the remote switch being in the correct state by periodically retransmitting the command code to the switch, eg transmit the on / off code every 5 minutes. Still not 100% reliable though.

Yes, I could write in sketch of RC-Switch-

sendON delay(2000) sendON

sendOFF delay(2000) sendOFF

Still not 100% reliable though. :cold_sweat:

Thank you very much jremington and mauried!!! :)