Introduction: Install Bootloader From Arduino Uno to an ATmega328P Microcontroller in 2023
After some frustration with trying to find up-to-date instructions, I thought I would pass along what worked for me.
Supplies
The light and resistor are optional but nice to have
- a 16 MHz crystal,
- a 10k resistor
- two 18 to 22 picofarad (ceramic) capacitors.
- wires
- LED (optional)
- 150 to 330 ohm resistor (optional)
Step 1: Wire It Up
Wire up and plug in the Arduino board and microcontroller as shown in the diagram and turn it on.
Step 2: Select Your Board
Select the board and serial port from the Tools menu that correspond to your board. (Arduino Uno COM#).
(Mine shows as Arduino Uno COM 4)
Step 3: Upload ISP
Select File: Examples: Arduino ISP: Arduino ISP. Then Upload the Arduino ISP sketch onto your Arduino board.
Step 4: Select Target Board
Select Tools: Board: Arduino AVR Boards: Arduino Uno (even if it is already selected).
Step 5: Set the ISP
Select Tools: Programmer, and check that it is set as Arduino as ISP.
Step 6: Burn the Bootloader
Select Tools: Burn Bootloader. The lights should flash on both boards.
YOU'RE DONE!

