340
Simulation
*Note Proteus VSM could not simulate I2C-based simulations. The simulation here only shows
connections.
Explanation
The code utilizes the same USI-based I2C library as in the USI-I2C example. Just like the software SPI-
based LCD example, the main difference is the way the LCD is driven. LCD data and commands are
sent through I2C bus and the PCF8574 GPIO expander IC converts these to parallel outputs. The
expanded GPIOs are then used to drive the LCD in 4-bit mode.