Connect External Keyboard to iPhone
This project allows you to connect an external infrared keyboard to your iPhone without jailbreaking. It uses Cypress PSoC microcontroller to emulate a simple modem, and then expanded it to detect an infrared signal or read from a USB host controller, which converts this signal to FSK for transmission to an iPhone.
To display the appropriate characters on-screen, an iPhone application has been created to decode the FSK signals to interpret the keyboard data. This interfacing project is designed by Zack Gainsforth and George Dean and need cost less than $20.