AVR Keyboard Interface Known as ATir

Overview

The ATir interface was designed to emulate the function of a PC AT keyboard and be controlled by an ATtiny45 microcontroller based IR remote control.

Explanation

An existing keyboard gets connected in series with ATir which can also be used without a present keyboard if the device is already programmed. An infrared receiver/demodulator and a few discreet components are featured in this compact system in addition to the microcontroller. It accepts commands from the infrared remote since the interface plugs into a PS/2 keyboard port on the PC.

An individual macro, stored in the EEPROM section of the microcontroller can store key sequences up to 64 keys in order to retain data after removing the power. The ATir can be connected to a PC without a keyboard after macros are defined. To allow operation, the necessary handshaking during boot up will be performed by the ATir. After the system boots, a keyboard can be connected to the ATir which will relay the information between the keyboard and PC.

The Atmel ATtiny45 microcontroller contained in the device hardware consists of low pass filter components and pull-up resistors. The ATir uses the 8MHz internal clock.