The dryer in our house is in an out-of-the-way corner where it’s hard to hear the buzzer. When we miss it, the clothes sit in the dryer getting wrinkly, so we start the dryer again, don’t hear the buzzer again … it’s an endless cycle. After what seemed like the thousandth time, my wife quipped, “I wish the dryer could just tell us when it’s done.”

I had just started playing with Arduino, so I thought a Dryer Messenger would be a good first project. When I ran the idea by my wife, she was enthusiastic but didn’t want me disassembling the dryer or voiding its warranty, since it was only months old. We decided to use SMS since our phones are usually nearby. Fast-forward a week or two and the dryer was texting us like a household assistant. We haven’t forgotten a load of laundry since.

Materials and tools

  • Non-invasive current sensor, 30a YHDC model SCT-013-030
  •  microcontroller, arduino Pro mini 328, 3.3V, 8mHz SparkFun Electronics #DEV-11114, sparkfun.com
  • Wi-Fi module, Roving Networks WiFly RN-XV
  • Breakout board for XBee module SparkFun #BOB-08276
  • XBee sockets, 2mm, 10-pin (2) SparkFun #PRT-08272
  • Protoboard
  • enclosure Digi-Key #HM1068- ND, digikey.com
  • Capacitor, 10μF
  • Resistors: 330Ω (2), 10kΩ (2)
  • Leds: green (1), red (1)
  • Headers, 40-pin breakaway, 0.1″ spacing (2) SparkFun #PRT-00116
  • stereo jack, 3.5mm SparkFun #PRT-08032 has pins with breadboard spacing.
  • dC barrel jack, 5mm×2.1mm SparkFun #PRT-10811 has pins with breadboard spacing.
  • Hookup wire
  • Wall adapter, 9V 650ma
  • Computer with arduino ide software free from arduino.cc
  • FTdi programmer such as FTDI Friend, Maker Shed #MKAD22, makershed.com, or FTDI Basic Breakout 3.3V, SparkFun #DEV-09873
  • soldering iron and solder

Downloadable Files


MAKE Volume 34: Join the robot uprising! As MAKE's Volume 34 makes clear, there’s never been a better time to delve into robotics, whether you’re a tinkerer or a more serious explorer. With the powerful tools and expertise now available, the next great leap in robot evolution is just as likely to come from your garage as a research lab. The current issue of MAKE will get you started. Explore robot prototyping systems, ride along with the inventors of the OpenROV submersible, and learn how you can 3D-print your own cutting-edge humanoid robot for half the price. Plus, build a coffee-can Arduino robot, a lip balm linear actuator, a smartphone servo controller, and much more

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