Programming arduino using another standalone arduino by serial communication

Hello, guys, I am working on a project to flash arduino using another arduino which was using external EEPROM to store the program need to be flashed using opti bootloader. I have followed the protocol of stk500 to flash another arduino but I was facing problem while flashing program over any other program which is already present in arduino.So, does anyone solution for this kindly share, please.

Note- I am able to flash arduino when flash memory contains the only bootloader.

If you start from one of the ones with the bootloader only, which you report works only once with your uploader, what happens if you try to program it with the IDE using a normal serial adapter - can you upload a sketch more than once that way?

If yes, you're probably not doing the autoreset correctly on your controller.

If not, that indicates you probably have the BOOTRST or BOOTSZ fuses wrong, or you're doing autoreset wrong in both places.

For details on how to make autoreset work, I'd need to know what board you're using, or if it's a custom one, what the schematic is. There are different caveats depending on what board you're using.

Thanx Dr Azzy for your advice but my problem has been solved. Now I am able to program one arduino uno by another arduino uno with program stored in external eeprom. :slight_smile: :slight_smile:

It would be useful for 'future generations' if you could indicate how you solved your problem.