Microcontroller module with USB connection 30 pin module, breadboard mountable Specialized library functions for robotics It is intended for roboticists, artists, designers and hobbyists Based on ATmega328 No pin headers The Arduino Nano USB Microcontroller v3 (No Headers) is a breadboard ready version of the Arduino Mini 05 Microcontroller Module with integrated USB. The Nano has everything that the Arduino Duemilanove USB Microcontroller Module has (electronically) with more analog input pins and an onboard +5V AREF jumper. The Nano automatically senses and switches to the higher power supply, so there is no need for a power select jumper.The nano's pin layout works well with the Mini or the Basic Stamp (TX, RX, ATN, GND on one top, power and ground on the other). The Arduino Nano USB Microcontroller v3 (No Headers) 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 selected to the highest voltage source. The package contains only the microcontroller. Features: Automatic reset during program download Power OK blue LED on the bottom Green (TX), red (RX) and orange (L) LED +5V to AREF jumper Auto sensing/switching power input Small mini-B USB for programming and serial monitor (cable not included) ICSP header for direct program download Power OK blue LED on the bottom Standard 0.1" spacing DIP (breadboard friendly) Manual reset switch