Getting An Arduino To Control A Wireless Outlet

[Reza’s] methodical investigation of this remote controlled outlet let him patch in with an Arduino using a 433 MHz transmitter. This is a single-device unit, but the techniques used here should allow you to take control of wireless rigs that have multiple modules to control many devices.

We’ve seen some folks at our local hackerspace try to patch into the remote control itself. That used some type of weird button scanning (not just connecting a pin to ground or voltage) and didn’t pan out. [Reza] doesn’t even crack open the case of either of the units seen above. Instead, he goes straight for a wireless receiver he had on hand, using a logic analyzer to capture the signals coming from the remote.

Once he had a good snapshot of the signals sent when pressing the on or off button of the remote he set out to replicate it in his Arduino code. His function called setStateWithDelay takes three parameters: the transmit pin, the level (high or low), and a number of milliseconds to delay. Each signal calls this function many times, but working the bugs out is pretty easy; just capture the signal with the logic sniffer and compare to the stock remote.

9 thoughts on “Getting An Arduino To Control A Wireless Outlet

    1. This library is really awesome and i use it with an arduino with ethernet for controlling my lights over webinterfaces/android app/etc…
      the library makes controlling 433mhz switches as easy as copy/pasting sequences :)

  1. The Mag Pi had a great article on capturing and reproducing these signals using the GPIO pins on a raspberry pi.

    You don’t need a logic analyzer. Hook a 50 cent receiver up to a headphone jack through a resistor and you get the same result in audacity.

    On the pi you can then control them using a cgi webapp or a cron job.

    Looks like another russian pencil.

    1. Long shot… It’s been many years since you posted the above… Anyway, are you sure it was MagPi? I looked through all the issues before Feb 2013 and could not find the article that showed how to capture such signals on GPIO…

  2. Question; are wireless doorbells usually 433mHz? Because this leads to some ultra cheap home automation if so. Doorbell rings, arduino/raspi turns on light, send email/sms. We need to make our own internet of things, it wont come unless we build it ourselves. I just bought the receiver/transmitter on ebay and have everything else, will keep ya posted.

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