RobotFuzz

The PCF8574 provides general purpose remote I/O expansion for most microcontroller families via the two-line bidirectional bus (I2C-bus).

The device consists of an 8-bit quasi-bidirectional port and an I2C-bus interface. The PCF8574 has a low current consumption and includes latched outputs with high current drive capability for directly driving LEDs. It also possesses an interrupt line (INT) which can be connected.

Features:

• Operating supply voltage 2.5 to 6 V
• Low standby current consumption of 10 uA maximum
• I2C-bus to parallel port expander
  
  Price £3.49

An Open Source InterFace is a USB to I2C converter.

This interface converts USB signals to the fast (400khz) I2C interface.

The OSIF is designed to control the OpenServo servo motor controller, but will serve as a generic USB to I2C interface.