The Nano for can be powered via the Mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically to the highest voltage source. The nano has 8 analog inputs,each of which provide 10 bits of resolution.By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the analogReference function. Analog pins 6 and 7 cannot be used as digital pins, some pins have functionality. It is a smallest, complete and breadboard friendly board. It has everything that for / has (electrically) with more analog input pins and on board +5V AREF jumper, compatible with , and Linux . More Breadboard Space:Nano's got the breadboard-ability of the Boarduino and the Mini USB with smaller footprint than either, so users have more breadboard space. It's got a pin layout that works well with the Mini or the Basic Stamp (TX, RX, , GND )on one top, power and ground on the other. This board is using the chips ATmega328P and CH340, not FT232 as official for ,Support ISP download; Support USB download and Power. Colour: blue Material: plastic + metal Package Contents: 4 * Nano Board Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.