The duino Nano is a small, complete, and breadboard-friendly board based on
the ATmega328 (duino Nano 3.0) . It has more or less
the same functionality of the duino Duemilanove, but in a different package. It
lacks only a DC power jack, and works with a Mini-B USB cable instead of a
|Operating Voltage (logic level)
|Input Voltage (recommended)
|Input Voltage (limits)
|Digital I/O Pins
||14 (of which 6 provide PWM output)|
|Analog Input Pins
|DC Current per I/O Pin
||32 KB (ATmega328) of which 2 KB
used by bootloader|
||2 KB (ATmega328)|
||1 KB (ATmega328)|
||0.73" x 1.70"|
The duino 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
The FTDI FT232RL chip on the Nano is only powered
if the board is being powered over USB. As a result, when running on external
(non-USB) power, the 3.3V output (which is supplied by the FTDI chip) is not
available and the RX and TX LEDs will flicker if
digital pins 0 or 1 are high.
Input and Output
Each of the 14 digital pins on the Nano can be used as an input or output,
using pinMode(), digitalWrite(), and digitalRead() functions. 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, some
pins have specialized functions:
- Serial: 0 (RX) and 1 (TX). Used to receive (RX) and
transmit (TX) TTL serial data. These pins are connected to the corresponding
pins of the FTDI USB-to-TTL Serial chip.
- External Interrupts: 2 and 3. These pins can be
configured to trigger an interrupt on a low value, a rising or falling edge,
or a change in value. See the attachInterrupt() function for details.
- PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output
with the analogWrite() function.
- SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins
support SPI communication, which, although provided by the underlying
hardware, is not currently included in the duino language.
- LED: 13. There is a built-in LED connected to digital pin
13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off.
The Nano has 8 analog inputs, each of which provide 10 bits of resolution
(i.e. 1024 different values). 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. Additionally, some pins have specialized
- I2C: 4 (SDA) and 5 (SCL). Support
I2C (TWI) communication using the Wire library (documentation on
the Wiring website).
There are a couple of other pins on the board:
- AREF. Reference voltage for the analog inputs. Used with
- Reset. Bring this line LOW to reset the microcontroller.
Typically used to add a reset button to shields which block the one on the