Problem: I want to try to assemble a circuit that would turn a light bulb (230V) on and off, controlled remotely by a PC. Ideally, the control will be over WiFi, next in line is Bluetooth and least preferable are RF and IR. Cost is a consideration and it would really be nice to be able to manage in 50-100$ total (including a newbie's kit).

About me: I'm a programmer and a total noobie to electronics. I want to learn to do such things. I also want my home lights to be controlled from a smartphone.


  1. Where to start? What should I know about electronics?
  2. I've read about Arduino, is this what I need?
  3. What components should I buy?
  4. How much should it all cost?
  • 1
    \$\begingroup\$ Unsuitable question. It should be closed. \$\endgroup\$ Feb 28, 2012 at 0:30

2 Answers 2


Arduino and XBee play nicely together and would be in your price range. There are a lot of videos to watch, blogs, articles and books to read about XBee.

You can make this cheaper, but you will have to do some design work or hack up a prototype.


Definitely look up other questions here about controlling line-voltage devices with a micro-controller. It is seriously dangerous if you don't do it right. Look up and read about opto-isolators.

Arduino is more than you need for this task, but if this project is for learning, and that you intend to eventually tear this one down and re-use the the Arduino in other things, it is a pretty painless way to go. An awful lot of design and preparation has been done for you up front, between the on-board facilities and the available programming tools. Arduino boards run from US$20 - 60, depending; but I'm guessing (from the voltage you want to control) that you're not doing this in the US, so you'll want to check your local sources.

I'm in the middle of a project right now that I started on an Arduino Mega2560. It has a lot of memory, built in serial I/O, lots of digital I/O, analog I/O (the 'O' is PWM, though, not true D/A), boot-loader already on the board, and USB powered. Great for getting started and learning my way around with no concerns for power supplies, tool-sets, etc. Now it's running on a bare ATmega 328p chip with a battery a few LEDs, and a 7-segment numeric display. The transition was easy once I was into it and knew I could compile and download a trivial "blinky" program to prove the breadboard was working.

Good luck!

  • \$\begingroup\$ thanks! how can I do this without Arduino? couldn't find anything.. \$\endgroup\$ Feb 28, 2012 at 1:01
  • \$\begingroup\$ +1 for the bold statement about being dangerous. @MichaelLitvin, its a good idea and a fun project, just be very careful when dealing with mains voltage. NEVER play with the wires when they are live. \$\endgroup\$ Feb 28, 2012 at 2:23
  • \$\begingroup\$ @michael-litvin: If you're comfortable bread-boarding or looking up how, do it with a bare chip and support components (some kind of power supply, capacitor(s), crystal, USB-serial cable for downloading, push-button for reset,...). If you'd like to see something up and running sooner and then learn to bread-board it, a development board like Arduino will get you there quickly. This tutorial - arduino.cc/en/Main/Standalone - will walk you through bread-boarding if that's your choice. BTW, that site covers nearly everything Arduino. \$\endgroup\$
    – JRobert
    Feb 28, 2012 at 23:58

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