user3029: I have an Atmega328P that I have previously burned with a bootloader configured to use the 8MHz internal clock as described here. I would like to now burn the normal Duemilanove bootloader configured to use an external 16MHz clock onto the chip. However, when I try following the normal procedure, it says "Invalid device signature". I can still upload programs to the chip and they will run, but I would like it to use the 16MHz external clock. How do I do this?

user10794: I have a sketch that will upload the Optiboot bootloader - that will work perfectly well on the Duemilanove.
The latest version will be available on GitHub.
This particular sketch is in the "Atmega_Board_Programmer" subdirectory.
You need to run this sketch on another Arduino (like a Uno) and connect it up like this:


3029: <p>I have an Atmega328P that I have previously burned with a bootloader configured to use the 8MHz internal clock as described <a href="https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard" rel="nofollow">here</a>. I would like to now burn the normal Duemilanove bootloader configured to use an external 16MHz clock onto the chip. However, when I try following the normal procedure, it says "Invalid device signature". I can still upload programs to the chip and they will run, but I would like it to use the 16MHz external clock. How do I do this?</p>
 10794: <p>I have a <a href="http://www.gammon.com.au/bootloader" rel="nofollow noreferrer">sketch that will upload the Optiboot bootloader</a> - that will work perfectly well on the Duemilanove.</p>

<p>The latest version will be available on <a href="https://github.com/nickgammon/arduino_sketches" rel="nofollow noreferrer">GitHub</a>.</p>

<p>This particular sketch is in the "Atmega_Board_Programmer" subdirectory.</p>

<p>You need to run this sketch on another Arduino (like a Uno) and connect it up like this:</p>

<p><a href="https://i.stack.imgur.com/QWfFR.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QWfFR.jpg" alt="Programming bootloader"></a></p>
