I²C interface for Centronics port

Many circuits, extensions and modules for the Inter-IC-Communications (I²C) bus have appeared in this magazine over the past few years. This two-wire bus designed by Philips allows ICs as well as complete modules such as TV tuners to communicate with each other. The principle of the bus also allows I²C circuits to communicate with a PC. Thanks to the circuit presented here, it is no longer necessary to insert a special interface card in the PC. The interface function is now taken over by the easily accessible Centronics (parallel printer port. That allows even portable computers to make use of the I²C Bus.