They used the webaudio API to send serial data to a remote Arduino. The hack uses a FET, a capacitor, and a few resistors. They didn’t quite build a real modem with the audio.

This application connects an Arduino that reads data from sensors* (temperature and humidity in this case) to a PHP application that stores the information on a Database and displays it with a ...

[Stewart] tipped us about his very nice project: pokewithastick. It is an Arduino compatible board (hardware, not footprint) based on the ATMEGA1284P which can be programmed to collect and post dat… ...

Arduino devices have had the option of a GSM linkup for awhile, but getting that cellular link to truly strut its stuff hasn't always been easy, even for those of us who'd be inclined to program ...