ATmega328P Microcontroller IC

This is a bare ATmega328P that's been loaded with the Arduino bootloader.

Features:

• ATMEGA328P (the P means this chip supports picoPower energy saving mode)
• Arduino Bootloader
• 8-Bit Processor
• 28 pin DIP package
• 32K of program space
• 23 I/O pins (6 pins are channels for the 10-bit ADC)
• up to 20MHz with external crystal
• Operating Voltage: 1.8V to 5V
• Can be programmed in circuit.