The Arduino Pro Mini is a micro-controller board base on the ATmega328 (datasheet). It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, an on-board resonator, a reset button, and holes for mounting pin headers. A six pin header can be connected to an FTDI cable to provide USB power and communication to the board.
The Arduino Pro Mini 5V is intended for semi-permanent installation in objects or exhibitions. The board comes without pre-mount headers, allowing the use of various types of connectors or direct soldering of wires. The pin layout is compatible with the Arduino Mini.
There are two versions of the Pro Mini. One runs at 3.3V and 8 MHz, the other at 5V and 16 MHz. This is the 5V version.
The Arduino Pro Mini can be powered with an FTDI cable or breakout board connected to its six pin header or with a regulated 3.3V or 5V supply (depending on the model) on the Vcc pin. There is a voltage regulator on board so it can accept voltage up to 12VDC. If you’re supplying unregulated power to the board, be sure to connect to the “RAW” pin on not VCC.
The power pins are as follows:
RAW. For supplying a raw voltage to the board.
VCC. The regulated 3 5 volt supply.
GND. Ground pins.
The ATmega328 has 32 kB of flash memory for storing code (of which 0.5kB is used for the boot-loader). It has 2 kB of SRAM and 1kBs of EEPROM (which can be read and written with the EEPROM library).