The Microchip ATmega328P CMOS 8-bit microcontroller is based on the AVR enhanced RISC architecture. It operates on 2.7V to 5.5V. The AVR core combines a rich instruction set with 32 general purpose working registers. It features 32K bytes of in-system programmable flash with read-while-write capabilities, 1K bytes EEPROM, 2K bytes SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible Timer/Counters with compare modes, internal and external interrupts, a serial programmable USART, a byte oriented 2-wire serial interface, an SPI serial port, a 6-channel 10-bit ADC (8 channels in TQFP and QFN/MLF packages), a programmable watchdog timer with internal oscillator, and five software selectable power saving modes. The idle mode stops the CPU while allowing the SRAM, Timer/Counters, USART, 2-wire serial interface, SPI port, and interrupt system to continue functioning. The power-down mode saves the register contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset.

Up to 16MIPS throughput at 16MHz
On-chip 2-cycle multiplier
High endurance non-volatile memory segments
Programming lock for software security
Two 8-bit Timer/Counters with separate prescaler and compare mode
One 16-bit Timer/Counter with separate prescaler, compare mode, and capture mode
Real time counter with separate oscillator
Programmable serial USART
Master/slave SPI serial interface
Power-on reset and programmable brown-out detection
Internal calibrated oscillator
External and internal interrupt sources
32-lead TQFP, and 32-pad QFN/MLF package