Can you burn a bootloader on a previously bootloaded Atmega328P?

HI guys, so i need to use a minimal standalone arduino, just the chip. I tried using your tutorial, other tutorials and so many things and failed every time. I'm using a chip that i took out of a arduino uno board, so my question is, can you burn the 8Mhz bootloader on an Atmega328p-PU that had another bootloader previously burned into it?

Yes you can install the bootloader as many times as you wish. And you can change bootloaders.

How, i tried the "normal" way but allways with errors like "invalid device signature"?

Well it depends on your definition of normal. Invalid device signature could be caused by anything, actually programming a MCU that has a different signature, damaged MCU, incorrect wiring, or fuses are set such that a crystal is required but you don’t have a crystal attached.

Please do this:

  • (In the Arduino IDE) File > Preferences
  • Check the checkbox next to "Show verbose output during: upload
  • Click “OK”
  • Tools > Burn Bootloader
  • After the Burn Bootloader process fails, you’ll see a button on the right side of the orange bar “Copy error messages”. Click that button.
  • In a forum reply here, click on the reply field.
  • Click the </> button on the forum toolbar. This will add the forum’s code tags markup to your reply.
  • Press “Ctrl + V”. This will paste the Burn Bootloader output between the code tags.
  • Move the cursor outside of the code tags before you add any additional text to your reply.