The Arduino Uno is a microcontroller board that is based on ATmega328. It has 14 digital I/O pins, 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button. The ATmega328 microcontroller has 32 KB of memory space. It also has 2 KB of SRAM and 1 KB of EEPROM.
Arduino Uno allows the analog port to be used as TWI, which in this case is the I2C. The pins A4 and A5 are used as SDA and SCL respectively . The Arduino Uno has two power supply connections, 3.3V and 5V. The MLX90614 works on 3.3V. With reference to the pin out diagram of the MLX90614 , we have the following connection as shown in the figure below (Bildr 2011).