The simulation only works for core pin manipulation. If your code uses LiquidCrystal.h or Wire.h , the virtual Arduino will simulate the I2C/SPI transactions perfectly because the library models the ATmega328P hardware peripherals.

Arduino Uno Library For Proteus 8.13 !link!

The simulation only works for core pin manipulation. If your code uses LiquidCrystal.h or Wire.h , the virtual Arduino will simulate the I2C/SPI transactions perfectly because the library models the ATmega328P hardware peripherals.