WebJack-Firmata is a transport layer for Firmata.js and is based on WebJack, a JavaScript library that uses an audio modem to communicate with an Arduino µC via headphone jack. Firmata is a RPC like protocol, that defines a serial interface to read from or write to a microcontroller's pins. This demo allows web browsers to control an Arduino via headphone jack.
To run the demo, upload this modified version of the StandardFirmata sketch. You will also need additional hardware.
Keyboard Demo
In this demo, specific keys are bound to pins, which are set high on keydown and low on keyup.