avrdude: stk500_getsync(): not in sync: resp=0x00 error

Posts: 2
Joined: Mon Nov 13, 2017 3:36 pm

avrdude: stk500_getsync(): not in sync: resp=0x00 error

Post »

Each time I try to upload a program to my Arduino Uno, I get the following error message:

avrdude: stk500_getsync(): not in sync: resp=0x00

What does this mean, and how can I fix it?

Posts: 3
Joined: Thu Jan 11, 2018 8:55 am

Re: avrdude: stk500_getsync(): not in sync: resp=0x00 error

Post »

Typically, this is a Bootloader issue (I've experienced this error many times).

When you get this error: avrdude: stk500_getsync(): not in sync: resp=0x00

Try this:

Change Tools->Processor->Atmega 328P to Atmega 328P (Old Bootloader). FYI the 'Processor' option is only available when you select some specific Boards at Tools>Board.

If that doesn't work, then don't panic...there are a bunch of other things you can try:

Disconnect and reconnect the USB cable.
Restart the Arduino IDE.
Press the reset button on the board.
Make sure you select the right board in Tools -> Board

If none of those work, you will want to try to isolate the issue by replacing things: i.e - Try a different computer with the same Arduino and vice-versa.

Hope that helps :-)

Posts: 11
Joined: Thu Apr 11, 2019 7:43 am

Re: avrdude: stk500_getsync(): not in sync: resp=0x00 error

Post »

Yeah, what @MakerFan stated. I've seen this loads of times. Basically, avrdude: stk500_getsync(): not in sync: resp=0x00 error has nothing to do with your code luckily, so (hopefully!) that will compile and upload just fine. You're seeing this error because your PC isn't communicating properly with your Arduino board. So check that your Arduino USB cable is correctly plugged into the Arduino itself as well as your computer, download the latest drivers, and head to Tools > Board to double check that you've selected the right Arduino. Also look under Tools > Serial Port to make sure that you're utilising the right COM port.

Posts: 2
Joined: Mon Nov 13, 2017 3:36 pm

Re: avrdude: stk500_getsync(): not in sync: resp=0x00 error

Post »

Thanks, guys!

Turns out it was a bootloader issue. I followed what Makerfan suggested (Change Tools->Processor->Atmega 328P to Atmega 328P (Old Bootloader) ) ...and Voila! Code uploaded and the error disappeared.

Hopefully, I won't be seeing avrdude for a while !!