Driving multiple LCD displays through an I2C interface
Jesus Echavarria tipped us off about his latest project of controlling multiple HD44780 LCD displays through an I2C interface. He used Microchip’s MCP23017 I/O port expanders and successfully drove eight LCDs with only two microcontroller pins.
Connecting multiple LCDs on an I2C bus
The MCP23017 device provides 16-bit, general purpose parallel I/O expansion for I2C bus. Upto 8 such devices can be connected on to the same I2C bus by varying their slave addresses through the hardware address pins. In his project, Jesus used eight MCP23017 devices (one for each LCD) to control eight LCDs over an I2C bus.