Powering you Arduino Nano:
There are totally three ways by which you can power your Nano.
USB Jack: Connect the mini USB jack to a phone charger or computer through a cable and it will draw power required for the board to function
Vin Pin: The Vin pin can be supplied with a unregulated 6-12V to power the board. The on-board voltage regulator regulates it to +5V
+5V Pin: If you have a regulated +5V supply then you can directly provide this o the +5V pin of the Arduino.
Input/output:
There are totally 14 digital Pins and 8 Analog pins on your Nano board. The digital pins can be used to interface sensors by using them as input pins or drive loads by using them as output pins. A simple function like pinMode() and digitalWrite() can be used to control their operation. The operating voltage is 0V and 5V for digital pins. The analog pins can measure analog voltage from 0V to 5V using any of the 8 Analog pins using a simple function liken analogRead()
These pins apart from serving their purpose can also be used for special purposes which are discussed below:
Serial Pins 0 (Rx) and 1 (Tx): Rx and Tx pins are used to receive and transmit TTL serial data. They are connected with the corresponding ATmega328P USB to TTL serial chip.
External Interrupt Pins 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.
PWM Pins 3, 5, 6, 9 and 11: These pins provide an 8-bit PWM output by using analogWrite() function.
SPI Pins 10 (SS), 11 (MOSI), 12 (MISO) and 13 (SCK): These pins are used for SPI communication.
In-built LED Pin 13: This pin is connected with an built-in LED, when pin 13 is HIGH – LED is on and when pin 13 is LOW, its off.
I2C A4 (SDA) and A5 (SCA): Used for IIC communication using Wire library.
AREF: Used to provide reference voltage for analog inputs with analogReference() function.
Reset Pin: Making this pin LOW, resets the microcontroller.
About Power
Vin: Input voltage to Arduino when using an external power source (6-12V).
5V: Regulated power supply used to power microcontroller and other components on the board.
3.3V: 3.3V supply generated by on-board voltage regulator. Maximum current draw is 50mA.
GND: Ground pins.
Resets the microcontroller.
Analog Pins A0 – A7 Used to measure analog voltage in the range of 0-5V
Input/Output Pins Digital Pins D0 – D13 Can be used as input or output pins. 0V (low) and 5V (high)
Serial Rx, Tx Used to receive and transmit TTL serial data.
External Interrupts 2, 3 To trigger an interrupt.
PWM 3, 5, 6, 9, 11 Provides 8-bit PWM output.
SPI 10 (SS), 11 (MOSI), 12 (MISO) and 13 (SCK) Used for SPI communication.
Inbuilt LED 13 To turn on the inbuilt LED.
IIC A4 (SDA), A5 (SCA) Used for TWI communication.
AREF To provide reference voltage for input voltage.
Arduino Nano Technical Specifications
Microcontroller ATmega328P – 8 bit AVR family microcontroller
Operating Voltage 5V
Recommended Input Voltage for Vin pin 7-12V
Analog Input Pins 6 (A0 – A5)
Digital I/O Pins 14 (Out of which 6 provide PWM output)
DC Current on I/O Pins 40 mA
DC Current on 3.3V Pin 50 mA
Flash Memory 32 KB (2 KB is used for Bootloader)
SRAM 2 KB
EEPROM 1 KB
Frequency (Clock Speed) 16 MHz
Communication IIC, SPI, USART
Difference between Arduino UNO and Arduino Nano
The Arduino Nano is very much similar to the Arduino UNO. They use the same Processor (Atmega328p) and hence they both can share the same program. One big difference between both is the size UNO is twice as big as Nano and hence occupies more space on your project. Also Nano is breadboard friendly while Uno is not. To program a Uno you need Regular USB cable where as for Nano you will need a mini USB cable. The technical difference between Uno and Nano is shown below.
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