What Arduino to use?

«What Arduino I can use?» : this is the first question that we ask ourselves after to start a do-it-yourself project. The choice between the various boards of rapid prototyping is vast and includes many types. (We can do a project fully embedded for example).

What Arduino we can use?

On this website was chosen an “Arduino Nano” inside of projects, decisive are the small size of the board (45×18 mm) that matched with the necessity of to have an CPU unity for the application cards, not renouncing Arduino’s intuitive ease and fast of programming.

Arduino Nano is equipped with an ATmega328, and it can be feeded with Mini-B USB, o through a Pin30 with an unregulated voltage between 6-20V or through Pin27 with an externally stabilized voltage included between the 4,5-5,5V. It have an internal memory from 32KB (where 2KB are used by bootloader), 2KB of SRAM e 1KB of EEPROM.

Serial: pin 0 (RX) and 1 (TX). Used for TTL serial data communications.
External Interrupts: pin 2 and 3. Used for handling external interrupts.
PWM: pin 3, 5, 6, 9, 10, and 11. They provide an output PWM signal.
SPI: pin 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support the SPI protocol.
I²C: pin A4 (SDA) and A5 (SCL). They support the I²C standard.

Arduino Nano have also 8 analog inputs with 10 bit of resolution (1024 colours) that of default and they go from 0 to 5V.

There are another one couples of Pin:

AREF. Reference voltage for analog pin measurements used with analogReference().
Reset. Bring the signal to LOW to reset the microcontroller, typically there is a button on the board.

Specifications:

Microcontroller	Atmel ATmega328
Operating logic level	5 V
Feeding (recommanded)	7-12 V
Feeding (maximum)	6-20 V
Digital Pins	14 (of which 6 PWM)
Analog Pins	8
Max current delivered for I/O pin	40 mA
Flash Memory	32 KB of which 2 KB used from bootloader
SRAM	2 KB
EEPROM	1 KB
Clock Speed	16 MHz
Dimensions	0.73″ x 1.70″
Lenght	45 mm
Width	18 mm
Weight	5 g