Basics of Arduino UNO:

Arduino UNO is nothing but microcontroller board based on ATmega328. The ATmega328 is single-chip microcontroller with Atmel. And the family is megaAVR.


This board includes digital input/output pins, a power jack, analog input pins, a USB connection, an RST button, and an ICSP header.

We can provide power to board using AC to DC adaptor, USB or a battery.

The important features of Arduino UNO:

  1. The operating voltage is 5v.

  2. The input voltage ranges from 6v to 20v.

  3. Digital input/output pins are 14.

  4. Analog input pins are 6.

  5. DC current for each input/output pins is 40mA.

  6. DC current for 3.3v pin is 50mA.

  7. Flash memory is 32kb.

  8. SRAM is 2kb.

  9. EEPROM is 1kb.

  10. Clock speed is 16MHz.

Hardware of Arduino UNO:



  • Fig.1 shows the basic hardware structure of Arduino.

  • The microcontroller is important part of Arduino i.e. ATmega328.

  • There are 14 digital input output pins which are mostly used to connect output devices like LED, LCD, and Relay etc.

  • There are 6 Analog pins which are used to connect analog input or sensors like IR sensor, RF sensor, PIR sensor etc.

  • Power supply for input / output component which is 5v and GND.

  • Power jack is used to give power to Arduino board where we connect the 9v battery.

  • USB port is used to upload program.

  • Reset (RST) button is used to restart the uploaded program.

Software of Arduino UNO:

  • Download the software Arduino ISE from and install it.

  • In the Arduino software, on clicking file there is one option i.e. ”Examples” by clicking on examples we can see the list of all programs available in it which are pre-written.

  • Next is sketch, in this the important part is include library. In library we can include the sensors library which is not present in the software.

  • Next is tools, in this port is select for operation.

  • In tools there one more option is presents i.e. boards, in that we can select the board which is used for operation for ex. Arduino UNO, Arduino mini, Arduino Mega.


LED blinking code:

Fig 2

Output of code on Arduino board:

Fig 3

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