To communicate with each LCD via I2C, two TCA9548A I2C multiplexers are connected to an Arduino, along with an RTC to keep track of the time and date itself. As the TCA9548A has three pins ...

Although there are other ways to do this, [Rod] has decided to write up his method of using two Arduinos and the I2C protocol to ... IO would be to buy an Arduino Mega with 54 digital IO pins ...