What is Bootloader..?

A bootloader is a small piece of code used in the Microcontroller’s memory. The bootloader in Arduino allows us to program Arduino over serial port i.e. using a USB cable. The job of Bootloader in Arduino is to accept the code from the computer and place it in the memory of the microcontroller. if you want to upload programs onto a new ATmega328 Microcontroller IC, you have to use a special programmer. But if you burn Bootloader on ATmega328, you can simply upload program the microcontroller over the serial port. Once the ATmega328 Microcontroller is ready with the bootloader, you can simply use it in your Arduino Board or use it as the microcontroller standalone board.

Components Required

Arduino UNO
ATmega328 Microcontroller IC
16MHz Crystal
22pF x 2 disc Capacitors
10KΩ Resistor
330Ω Resistor
LED
Breadboard
male to male jumper wires

circuit diagram