16-Channel Open Collector Driver MCP23017 with I2C Interface

This device consists of a MCP23017 general purpose input output port expander connected to two ULN2803 open collector output controllers. This device can be used to control up to 80ma of current per channel using I2C communications. Applications include control of small incandescent lights, relays, super-bright LEDs and other low-power devices. This device will connect or disconnect external loads to ground to turn them on or off. Voltage is applied to the external load with the ground connection flowing through this controller. Up to eight of these devices can be daisy chained to a single I2C port using 3 on-board address jumpers. The MCP23017 should be programmed to 8-Bit Output mode for proper operation, each open collector output is activated when bits are turned on. Eight on-board status LEDs are dim when outputs are off. LEDs glow bright when outputs are activated. Our example library makes it easy to use this device across many platforms.