Helppppppppppppppp Watchdog problem!

Guys i'm burning!I've got a big problem! I've done something very very stupid like newbie!I see from a forum that i can restart the board( Arduino mega 2560) with watchdog.

So the problem is that from then when i use an example every 15ms board is restarting, It stucks on restarting and it not let me to upload a new sketch.What should i do ??I want to save my board pleaseeeeeeeeeeeeeeeeeeeee!!!

Thanks in advance!

sirus: Guys i'm burning!I've got a big problem! I've done something very very stupid like newbie!I see from a forum that i can restart the board( Arduino mega 2560) with watchdog.

So the problem is that from then when i use an example every 15ms board is restarting, It stucks on restarting and it not let me to upload a new sketch.What should i do ??I want to save my board pleaseeeeeeeeeeeeeeeeeeeee!!!

Thanks in advance!

I suspect you need to burn in an updated bootloader for the 2560 that correctly handles WDT interrupts. I know one exists but where you find it and what you will need to install it are details better left to those with first hand experience. I'm sure help and advice will soon follow.

Lefty

Have you got an ICSP programmer (like USBtinyISP) or another Arduino board? With one of those you can change the bootloader.

For now, though, you should be able to recover by getting another sketch ready (eg. blink).

Power off your board (ie. unplug the USB) and plug it back in while holding down the reset button. Keep it held down (you might need a friend to help) and then hit the Upload button on the IDE. When it starts to upload, release the reset button. That should go straight into uploading mode without running your sketch, and therefore without changing the watchdog timer.

Next time, go easy on the 15 mS watchdog. Normally something like one second should be enough.

If you don't have a friend handy, and have trouble managing it all single handed, plug a jumper between reset and Gnd. Then at the appropriate moment pull the jumper out.

Thank you very much Nick for your very very usefull informations.I want to ask you something else...!Do you believe that my problem is gonna fix if i burn new bootloader?? Have you got a website which contains step or guides about it?You're much experienced than me so let me trust you my friend???

The 2nd way in order to replace the old sketch with a new one i thing that is pretty much imposible.I should try every day and all night something like that...

As for the programmer:

Do you believe that something like this could do my job??? http://www.ebay.com/itm/USBTiny-USBtinyISP-AVR-ISP-programmer-for-Arduino-bootloader-with-guide-/320916643827?pt=LH_DefaultDomain_0&hash=item4ab81f5ff3

Thank you very much.

If you burn the correct bootloader, yes. In fact burning a bootloader generally removes the sketch as well, so it would fix your problem as a side-effect.

The USBtinyISP is the one I use most of the time so that should do it.

If you have a spare Uno you can use that to upload the bootloader:

http://www.gammon.com.au/forum/?id=11635

OK i understand Nick everything and now i've got more clear mind.But to be 100% sure for what i'm doing, how can i find the correct bootloader?In arduino's folder C:\Arduino\hardware\arduino\bootloaders?

Which of the should i burn?? Or should i go in website to find the same bootloader? You calm me alot and thank you very much!I was ready to buy a new one.My work is to programming the embebbed part and develop an C# application with this. I've almost complete everything, and i've stuck to this foolish which i've done.

Thank you very much for one more time....

I think it’s this one:

C:\Arduino\hardware\arduino\bootloaders\stk500v2\stk500boot_v2_mega2560.hex

But like I say, once you burn the bootloader it gets rid of the sketch (it erases flash) so your problem sketch will be gone too.

Thank you very much Nick! I don't care for my sketch!I've got the code so i don't bother about it....

Thanks for one more time!