Uploading Sketches (not in sync) Is Not Possible (Anymore..)


i know that there are already a lot of these issue (avrdude: stk500_getsync(): not in sync: resp=0x00) solutions spreaded on the web, but i read the troubleshooting and fighted through a lot of entries and haven´t found the right one yet.. so i hope one of you guys have maybe a specific solution.. :)

it worked yesterday and isn´t anymore since today.. i tryed a different circuit (#10 from vilros) when it "happend", but i don´t think that the issue is here.. nothing is working now, not even the easiest circuit (read somewhere that a wrong pin use can also "disconnect" and evoke this issue).. i guess it´s not the code or the circuit!

i tryed it with multiple usb deviced on win 8.1 (64bit) and win 7 (64bit). based on the troubleshooting thread, the bootloader should work (led is blinking). but he isn´t finding the usb #3 on win 8.1 anymore with the ide.. = it was also plugged in usb #3 when it ceased working.. there i get a "avrdude: usbdev_open(): did not find any USB device "usb"".. so he isn´t finding usb# 3 in win 8.1 and is´t working with the other plugs.. and is also not working with any usb plugs from win 7 on a notebook..

ide = 1.0.5 - arduino uno r3 and yes, i got the right board :)

havent had the possibility to check it with another usb cable..

maybe one of you have an idea?


Does it work if you hit the reset button on the board .1 seconds after starting the upload?

In my limited experience so far, that error message happens when the Arduino refuses to reset. I use a breadboard Arduino equivalent, so it my case it usually means I've dislodged one of the comms pins or particularly the reset wire. Obviously, anything that stops comms from working reliably will cause this error, so it could be lots of things, e.g. wrong bootloader using wrong baud rate. But most of those become increasingly unlikely in a setup that was previously working.


unfortunately not. tryed it multiple times and with multiple variants (before, 1 sec after, after every plug change....) reseted it felt 100 times : )

is the reset button the deepest instance? i mean would it help to let it unplugged for xx time like by a motherboard where u have to remove the motherboard battery for killing the bios password.. ?

is there a possibility to check something like a wrong baud rate?

Unplugging is basically a power cycle, and no it will have no effect. Resetting the board much before the upload will not help either.

When you start an upload the first thing avrdude does is try to reset the board. On reset the board will run the bootloader, which will check for and download the new firmware. Avrdude doesn't know how long it will take for the bootloader comms to respond, so it will wait a little while (I've not checked how long). So, if you start the upload and then immediately hit the reset button then you can compensate for avrdude being unable to reset the board for some reason.

However: if the problem is not reset then the above will not help. You would then need to look to other reasons for comms failure - there are a huge possible number of reasons for this, starting with configuring the wrong serial port selected or the wrong baud rate on the host (check), damaged cable (try alternative), down to fried RX and TX pins on the AVR (try carefully replacing with a known good ATmega328p).

gRoTeSk: is there a possibility to check something like a wrong baud rate?

If the same AVR was working before then the AVR can't have changed baudrate - the bootloader baud rate is hard coded. Presumably you must know if you changed the baud rate in the Arduino PC IDE. On current Arduino Uno's using the optiboot bootloader the baudrate is 115200, in my experience.

thx for your help DonMilne.

FYI: it was the first of your reasons :) -> installed the uno under windows 8 like in the youtube video under -> http://forum.arduino.cc/index.php?topic=205882.0..

had to choose usb port 2 and set a max. transmission rate. by windows, usb #3 is assigned.. maybe this overlap led to the issue? makes in some way no sense cause it was the same on 2 pcs.. but how ever, it works again..

It seems to be normal behaviour for USB-RS232 adapters to be assigned different COMx numbers based on which USB port they're plugged into, and what else is plugged in at the time. The same applies to drive letters for storage devices. It's a pain all right.

sry for spaming this thread, but i have not had any issues like this before yesterday.. it hadn´t mattered which port i use.

so after it worked again i retryed the motor circuit more aware:

the first upload worked well, after i set the speed per serial monitor it caused an error and led to the port issue. but after assigning it to a port and fixing the issue this way, i can plug it again where i want..

i´d like to post the code, but it´s not mine.. copyright (?).. but i have this issues with the vilros ultimate handbook circuit #10

Did you try searching the board? This or similar errors comes up a fair amount of times.

Your Arduino probably has a counterfeit FTDI chip. Windows may have updated the driver, which doesn’t seem to work with the counterfeit chips. Download and install an older version of the driver, it worked for me. I bought a couple of Nanos that won’t work with the latest driver, but do with the driver downgraded.

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