My washing machine doesn't have any bells/whistles/buzzers to let me know when it's done. I just got my first Raspberry Pi and am thinking wiring it up so it texts me when a load of clothes is finished would make a good first project. First thing I need to get started is a way to monitor the current going to the washer. (There is nothing digital on the washer so when it's not running there is no current moving.)

I can think of three options:

  1. Wire the Raspberry Pi directly to the washer cord to monitor changes.
  2. Use something that go between the washer cord and the wall that can signal the Raspberry Pi.
  3. Use something that will monitor current going through the cord externally.

I would much prefer to do option 2 or 3 since I'm new to this. Is there something like a SmartThings SmartPower Outlet that can talk to a Raspberry Pi?

  • 1
    Usually setting a timer like 90 minutes on my phone did the trick for me, but I admire your enthusiasm :)
    – Piotr Kula
    Commented Jan 8, 2015 at 13:36
  • 2
    Yep. The phone timer is exactly what I use now. It's burned in my mind that a regular load takes 27 minutes. This project is more about a first experiment with a Raspberry Pi. Not having to deal with setting the phone is a side benefit. ;) Commented Jan 8, 2015 at 14:34

2 Answers 2


You could make a tweet a watt (option2). Alternatively, you could use a clamp on current sensor - as discussed on the Raspberry Pi forums (option 3)

There are a couple of alternatives that you may not have thought about:

  • If the washer has an LED you can monitor that,
  • depending on how loud the ambient noise level is you could use a microphone,
  • you could attach a piezo disk/vibration sensor, or
  • simplest of all set the Pi up as a timer that you set when starting the washer.
  • 1
    All very good suggestions and if all fails, yea, timer always did the trick ;)
    – Piotr Kula
    Commented Jan 8, 2015 at 13:37
  • You could use a waterproof wireless pedometer inside the drum to detect start and end of centrifugation.
  • You could use a small floatation device in the drain or a simple electrical circuit in the drain pipe to detect when the machine is emptying.
  • If SmartThings uses some open standard wireless protocol, you can definitely use that, but it might need some reverse engineering. Also maybe have a look at http://www.thesmartcord.com/
  • 2
    Probably not the direction I'm going to go, but definite points for creativity on these. Commented Jan 9, 2015 at 9:07
  • :-( "The smart cord" looks like it's no longer available Commented Sep 8, 2017 at 21:50

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