William Finucane of revoltlab.com posted this article describing a simple low-cost means of activating devices remotely via telephone.
I wanted to be able to call my house and turn on the lights and television during nights when I was away on vacation. What’s more, I didn’t want to spend any money on cell phone bills and wanted to be able to use virtually any phone. I came up with a light-activated cell phone switch box that uses the display screen that you get from an incoming call to control a physical output.
The BOM consists of an Arduino, LDR (light dependent resistor), 10k resistor, breadboard and servo.
The hoz via the contact form.