Since we’re so focused on our email and text nowadays, we often neglect to check our snail mail. Now, with the help of an Arduino, you can easily setup notifications and alerts for just about anything. This project uses an Arduino, a PHP-enabled web server and Prowl (an iPhone app) to build the lert system for your mailbox. A small switch is triggered when the mailbox is opened. The Arduino takes this signal and requests a URL from the PHP server that can be setup on your own computer or online. The PHP Proxy Server sits between the Arduino and Prowl’s API so that they can connect using a secure SSL connection.
The PHP server code (ProwlPHP) is free, downloadable, and all you have to do is paste your Prowl API key. The Snail Mail Push Alerts project is a fine example of a basic Arduino project that connects the physical world with the digital one.