50% failure when trying to load 8Mhz Bootloader

[nigelttttt]

Good day
I wonder if someone could shed some light on a problem I am having with bootloaders.

The project I am working on needs low power and a low component count so I find myself messing with internal crystal 8Mhz bootloader

I have about 20 or so ATMega328's and about 50% of them seem to fail when I load up a 8Mhz BL then try to upload a sketch (serial communication error)

If I reburn them with the standard ArduinoISP they work

The bootloader I am using is ATmegaBOOT_168_atmega328_pro_8MHz.hex

[hmeijdam]

When burning for 8MHz with the standard Arduino boards I suspect the fuses are set in a way it expects a 8MHz external crystal.

You could install the minicore core which has an option for burning the bootloader with the internal 8MHz oscillator as clock source.

[nigelttttt]

Thanks for the reply hmeijdam

I do not have those options on my menu (I am using ID 2.2.1)

Where would I find those pls

Thanks

[hmeijdam]

You have to add the MiniCore package in your Arduino IDE.

Here you can read how to install

[ptillisch]

Hi @nigelttttt.

@nigelttttt

If I reburn them with the standard ArduinoISP they work

By "ArduinoISP", do you mean an Arduino board running the sketch available from the File > Examples > 11.ArduinoISP > ArduinoISP menu in Arduino IDE?

The reason I ask is because there is a programmer named "ArduinoISP". Despite the name, this programmer does not use the "ArduinoISP" sketch and is very different from the programmers that do use the sketch of that name. So confusingly the programmer name for an Arduino board running the "ArduinoISP" sketch is actually "Arduino as ISP", not "ArduinoISP".

You mention "ArduinoISP" in relation to the "reburn" operation. Were you using the same programmer the first time when the "Burn Bootloader" operation failed, or did you switch programmers for the "reburn" operation?