Note: Download aduino IDE ATmega 328P (old bootloader) the USB chip driver first. An additional expansion board which brings the I/O out to a series of screw terminals that can be handy for projects that are interfacing with a lot of wiring. The Nano has a number of facilities for communicating with a computer, another Arduino, or other microcontrollers.Such as UART TTL (5V) serial communication and I2C (TWI) and SPI communication. Nano V3. 0 ATMEGA328P Improved version with 3pcs pin headers soldered (2pcs 15pin headers +1pcs 6pin headers). Each of the 14 digital pins on the Nano can be used as an input or output.They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, analog pins 6 and 7 cannot be used as digital pins, some pins have specialized functions. The Nano is a small, complete, and breadboard-friendly board based on the ATmega328P (Arduino Nano 3.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package. The Nano 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.