The Arduino Pro Mini is a microcontroller board based on the ATmega 328P from Atmel (datasheet). It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, an on-board 16Mhz resonator, a reset button, and holes for mounting pin headers (2.54mm). A six pin header can be connected to an FTDI cable.

The board comes only with holes (with 2.54mm spacing), without pre-mounted headers, allowing the use of various types of connectors or direct soldering of wires.

The pin layout of the Pro Mini board is compatible with the Arduino Mini.

This version of Arduino runs at 5V and 16 MHz, but it has a raw power connector where you can add power supply from 5V up to 12v (DC voltage!).

 Arduino Pro Mini specs

- Bootloader write inside

- ATmega328 CPU

- speed 16MHz with external resonator (0.5% tolerance)

- USB connection off board

- 14 Digital I/O Pins (6 for PWM)

- Supports auto-reset

- Max 150mA output

- Over current protected

- Reverse polarity protected

- DC input 5V up to 12V

- On board Power and Status LEDs

- Size: 33mm *18 mm *6mm (high)

- Ebay price 5$

This Arduino Pro Mini can be programmed with the Arduino software.

The Arduino Pro Mini has a number of facilities for communicating with a personal computer or another Arduino. The ATmega 328p provides UART TTL serial communication, which is available on digital pins 0 (RX) and 1 (TX).