The PIC16F873A-I/SO is a 8-bit CMOS enhanced Flash-based Microcontroller. The PIC16F873A features 128 bytes of EEPROM data memory, self programming, an ICD, 2 comparators, 5 channels of 10-bit Analogue-to-digital (A/D) converter, the synchronous serial port can be configured as either 3-wire Serial Peripheral Interface (SPI™) or the 2-wire Inter-Integrated Circuit (I²C™) bus and a Universal Asynchronous Receiver Transmitter (USART). The PIC16F87XA devices have a 13-bit program counter capable of addressing an 8K word x 14 bit program memory space.