burn custom bootloader to arduino

Using Arduino Programming Questions
1

ive compiled a custom optiboot bootloader but i cant figure out how to flash it. im going to be flash a mega2560 and a mega328p. everything i read says to use board manager. i have the hex files. as a note iv never done this before so im not really sure what to do. ive only used board manager to flash official bootloaders how do i flash these custom bootloader?

2

Just like how you would program any other hex with a programmer :slight_smile:

You could do it via the IDE if you make your own board definition but AVRdude is easier I think.

But in reality, why mess with bootloaders if you don't know how to program a hex?

3

septillion:
Just like how you would program any other hex with a programmer :slight_smile:

You could do it via the IDE if you make your own board definition but AVRdude is easier I think.

But in reality, why mess with bootloaders if you don't know how to program a hex?

i know how to send the sketch hex with avrdude but not the bootloader. i had to change the optiboot watchdog timer so i have less problems uploading my sketches through the wifi. Is it a matter of just sending the hex file or do i have to specify that its a bootloader and the starting address?

for example when uplaoding my sketch "avrdude -p atmega328p -c stk500v1 -P net:10.0.0.110:2323 -b 57600 -U flash:w:hex.hex -D -F"

4

Ahh, you're that guy.

But sorry, I'm out if you try to upload bootloaders via the network to programmers I don't know, sorry.

5

septillion:
Ahh, you're that guy.

But sorry, I'm out if you try to upload bootloaders via the network to programmers I don't know, sorry.

i never said i was trying to upload a boot loader over a network. but i understand if this is beyond your scope

6

Because of the net option when you call AVRdude I assumed. But yeah, don't do it often enough to tell you from the top of my head, sorry.

7

If you have a non-networked board for testing, you can burn the official bootloader with the IDE and that will show you the avrdude commands used. From there you should be able to modify the commands for your custom bootloader.

8

what problem do you have with watchdog and Optiboot while doing a network upload? how do you do the network upload?

Mega doesn't use Optiboot at default so the upload speed and fuse settings of Arduino AVR core don't work. you could use MegaCore boards package