Can't upload sketch!


I can't upload anything to my arduino. It was working fine like 10mins ago, and it has just died. When I upload, it just says:

avrdude: stk500_getsync(): not in sync: resp=0x18 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x78

There is a sketch on there at the moment, and it's sending serial messages that I can recieve. So, the Arudino works. And it's totally using the right port.

And yes, ive restarted everything.

Any ideas?

Edit: Tried reinstalling the fdti drivers, nothing. I need this project finished for Tuesday, so any help would be great :). Been reading a few posts with the same problem, and none of them seem to solve it. Is it possibly a bug?


Nick D

I don´t know if this problem is the same, but I read somewhere in this forum about a sketch that sends constantly messages from arduino´s serial port, and makes it uncommunicable to receive new sketches. Is the actual sketch a loop of this kind?


Well that's the feeling im getting. Is there a way to reset the arduino to factory settings? I think the sketch sending serial data is what's causing the prob.

Just if it helps, im running: Vista sp1 Arudino Diecimila

I would just buy a new one, but ive got to fly out to Berlin on tuesday, typical bad timming ;)


You can try to reburn the bootloader.

Yeah i was thinking that, but don't i need some kind of fancy programmer todo that?

The cheapest way is to use a parallel port programmer:

Ok, that's one option.

Tried another PC, same problem. I really was planning to take this project with me to Germany on Tuesday, so if anyone has any ideas how to fix this without a programmer, i would be most appreciative!!


Which arduino is it?

What do you have hooked up to the board?

Is it getting power?

You should not need to reload the bootlader.

If you think you are putting out a lot of serial traffic you can verify this buy turning on the serial monitor in the arduino ide. You should see the output.

When you “Upoad to board” the arduino board automatically gets reset, and listens for a short period on serial to see if a new sketch is being uploaded.

Today i had the same problem: I just disconnected all Peripherie from the Ardiuno (2009), upload the new sketch again and anything works fine ...

I get the same error as OP. I'm going to try some more snake oil today, including possibly the parallel port programmer.

Just got back from holidays! So to answer your question:

Which arduino is it? Diecimila

What do you have hooked up to the board? Nothing, other than the USB lead.

Is it getting power? Yes, to works

If you think you are putting out a lot of serial traffic you can verify this buy turning on the serial monitor in the arduino ide. You should see the output. Yes, there is a programme on there outputing serial data. I can read this, so I know the board works.

I dont even have a parallel port on my notebook. Is there any solution, because im not really in the mood forking out for a new one.

edit: Seems since ive been away even more people have had this problem, with no obvious solution. Is this a major bug?


Nick D

That's why there is supposed to be a short delay after pressing reset... no? That delay allows you to UPLOAD a new sketch with the bootloader. If you wait too long... you miss the window and you will have a serial conflict as seen.

If you have a different bootloader that has the delay removed... oh well.

I haven't changed the bootloader, can you explain what you mean by this?

can you explain what you mean by this?

Connect the board to the computer. Ensure you've selected the right serial port in the IDE. Hit the Reset button on the board. Hit the Upload Sketch button on the IDE before two seconds has elapsed.

When you hit the reset button, the board starts running the bootloader program instead of your program. The bootloader program watches the serial connection for two seconds, and if there's nothing that looks like a valid program-upload process being attempted, it will start running your program.


I'm having pretty much the same problem, and have gone through as much doc and forum notes as I can find.

I'm running Windows XP, have an older Arduino NG with '168 that I bought about 2 years ago but am just now trying for the first time. I've tried hitting the IDE's upload button everywhere from as-soon-as-i-can-after-pressint-the-reset-button to about the middle of the led-blinking period to as long as 10 seconds after the led stops blinking. I uniformly get:

avrdude: stk500_getsync(): not in sync: resp=0x00 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

I've programmed AVRs directly from the Atmel Studio IDE, and even used avrdude a time or two, so this frustrating :-[ ... and a bit embarasing ;)

Has anyone figured out what's going on?

cheers, Don

Yeah, i tried resetting my arduino manually pretty soon after this prob came up, with no avail. I think the Arduino head honchos need to admit this is a bug and look into it.

Hi All,

my son & I just got an Arduino and everything worked fine till now when I tried to send something out of the serial port. Now I can no longer upload - even though my old program on the Arduino still works. Basically its identical to what the others are reporting here! The message on the console is:

avrdude: stk500_getsync(): not in sync: resp=0x30 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

I've tried playing with pressing reset and immediately hitting upload to get it in those 2 secs - but nothing works - HELP !

I feel your frustration ;)

I got my arduino duemilanove today and had the same error message today. I had to change to com 5 in order to get it to work. Apparently, it does not automatically detect and configure all of the correct settings. Once I did this, it has worked fine.

Now, it's time to start learning and having fun. Best of luck to you.

Good One Flyboy! I changed USB ports and it works!!! I was waiting for some components I ordered to build my own parallel programmer to reload the bootloader - Sooo glad I didn't do that!

However, it now works but when I open the Serial Monitor the Arduino starts sending gibberish data even though I have no Serial.X code - need to look into this...

FYI, I am using Vista on the PC