Solution: avrdude stk500_getsync(): not in sync resp=0x30 error for Arduino

So the reader is aware: This article covers the main causes for this issue, but some of the other Instructable users have found somewhat "niche" causes to the issue that were not covered in this article and are discussed in the comment section below. If this article does not solve your problem, please visit the comment section below.

I have had this error: I would plug my Arduino Uno into my Windows 7 PC (this guide should be relevant for Windows 8, Vista and XP also) but whenever I would upload any sketch to the board, all I would get is

avrdude stk500_getsync() not in sync resp=0x30

for a response. This board however worked seamlessly with my Linux machine.

After much searching online, I found there was no 'clear' solution to this.

Joyfully, the fix is actually very easy (at least for me, hopefully for you as well!). So far, there seems to be 2 3 big causes to this issue:
  • A wire is connected to pin0
  • You have the wrong COM port selected (the IDE does not see your board)
  • Your Arduino drivers are not set properly.

Unlikely Cause #1: Bootloader is missing

Before we begin, we should check the bootloader of the Arduino for comprehension. If the bootloader is gone or corrupt, this can cause the issue.

To do this: power and reset the board. Check to see if the pin 13 built-in LED lights; if it is not then your bootloader may be missing. If this is the case, then your problem is beyond the scope of this guide. I would suggest visiting this Sparkfun guide:

If the LED lights, then your bootloader still exists.

Cause #0: Wire coming out of pin 0, (RX)

All credit goes to tvance929 and his comment below for finding this one. Some people seem to have this happen to them so it seems worth it to bring this up top here.

Apparently this issue will also occur if you have a wire connected to pin 0 (RX) on the Arduino.

Cause #1: Wrong COM Port 

With the Arduino plugged to the computer, open "Device Manager" and check the "Ports". Check to see if an Arduino device is listed here; if it is, then make note of which COM port the Arduino is on and check that you have this selected in the Arduino IDE (Tools -> Serial Ports). If the COM port your board is on does not show within the IDE, then try different USB ports.

If you can't even see "Ports"; then for some reason, your computer isn't even recognizing that a device is plugged into it. Test your computer by plugging other USB devices into that port. Possibly your Arduino fails at life; try it with other computers.

Cause #2: Drivers not Installed

This is what you should see when you open Device Manager:

If you don't see an Arduino device listed under Ports; then you are probably seeing an "Unknown Device". Check to make sure that "Unknown Device" is indeed, the Arduino by plugging and unplugging the board from the computer. "Unknown Device" should appear and reappear. Assuming this is the case, you will need to install the drivers manually for your Arduino. Windows XP, Vista and 7 users may continue with the guide; if you are a Windows8 user, then please make reference to the comment left by finnigan16 below.

Right click on that "Unknown Device" and select "Properties". Click on the "Driver" Tab. Below, you can see I already have the driver set, hence why my window reads "Arduino UNO R3 (COM4) Properties", when yours will probably read "Unknown Device Properties".

Select to "Update Driver..." and then choose to select the folder containing the driver on your computer. Conveniently, you already have the drivers for the Arduino on your computer when you downloaded the Arduino IDE. Navigate to the Arduino folder you downloaded that contains the Arduino IDE.  In that folder, go to the "drivers" folder and choose the "drivers" folder itself (see the picture below for the path). The computer should automatically choose to install one of the drivers within the folder you selected. Simply proceed with the installation and that should fix the problem.

Make sure the Serial Port is then selected correctly!

If you have checked the possible causes discussed here and your issue still isn't solved, be sure to check the comment section. Some of you have found niche causes to the issues which are discussed below.
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finnigan161 year ago
great Instructable. Unfortunately It didn't work for me, however I did find a fix so I thought I'd post it here for anybody else with the same problem. My problem is that I'm using Windows 8 and apparently the arduino drivers aren't signed and therefore windows 8 will not utilize them. Fortunately YouTube user beachedwhale found an easy work around that'll get it working without turning off driver signing. You can watch his video by following this link:

In a nutshell, you update the driver through device manager and use the wizard to pick from a list of device drivers on your computer, when this list comes up you choose a Compaq Ricochet Wireless USB Modem, apparently the two devices use the same driver, you just need to change a few of the driver's settings once it's installed (make sure the baud rate is 9600, etc...).

It only takes about two minutes to do, definitely worth a try if your getting this error and running Windows 8.

but it didnot work for me. i have tried many process and still the problm is not solved

N.fletch (author)  finnigan161 year ago
I never verified this error with Windows8; thanks for helping make my Instructable more comprehensive. I'll make an edit above pointing to this for those with Windows8.
SabriM7 days ago

Just watch the video below. The guy answers in the last seconds. 3.57 sec .

Pretty simple. Plug off tx and rx cable and upload. Then plug them in. Thats all.


tvance9297 months ago

My problem ... I had a wire coming out of pin 0 -- Dont do that when uploading... ugh!

"DISCONNECT ANY WIRES going to pin 0 (RX) while you do the upload." <-- thanks Keith!


N.fletch (author)  tvance9292 months ago

Stuck your solution up top here; all credit is for you. Thanks!

Cool!!! Thanks Fletch! **But honestly, all I did was find Keith Parkansky's site - he's the real hero! **

Thanks a lot ..It helped..

That was my problem as well it took me 5 hours of searching the net to fix it !!! thank youuuuu

@tvance929 - thank you! That was my problem, too.

You saved me a lot of pain! I don't know what changed, I tested out my system, a greenhouse control, then placed it in the greenhouse. It failed, a wire disconnected. I brought it back in, and had this problem. Fortunately, I came across your suggestion quickly. I adjusted my outputs to begin at 1 rather than 0, and poof, problem solved! So a wire in output 0 seems to generate the problem intermittently.

@tvance929 You were the guy for my problem ! Thank you for sharing your fix. I indeed did connect my pin 0 to the Tx of a device i want to control from my arduino and ended up with this error (resp=0x07 in my case).

The funny thing is that i even didn't need to connect this pin since i'm not expecting any data from my device, just have to tell it what to do.

Thanks to Keith too :)

cdogjune17 days ago

I got this error and found that I didn't have the correct version of arduino selected in my setup.

I'm getting the same error with a Nano. I hit "Ctrl+U" (upload), and after a while the console says "avrdude: stk500_getsync(): not in sync: resp=0x00". I have observed that the Nano isn't showing up as an Arduino on COM3, but rather just a USB Serial Port. I've tried everything I know about drivers, and nothing is happening. Can anyone help me?

one VERY useful comment to add is to make sure no other programs are currently using the specific COM port that the Arduino is using. For example, I spent 2 hours trying to fix the error described in this page, and then I realized that I had run a few MatLab commands that opened the serial port but I never closed it. The problem persisted even after uninstalling and then reinstalling the Arduino drivers, until I told MatLab to close the serial port.

Also, try restarting your computer in worst cases...

Thanks for the helpful instructable!

avrdude stk500_getsync(): not in sync resp=0x00 <--- 00 was my problem, i wasn't pressing the reset button at the right time, i dont have an auto reset USB to Serial,, no DTR pin, so i was looking everywhere for the right reset method,some said keep holding it untill it shows upload, some said press once right before upload, nothing worked, but somewhere i found that if i turn on verbose output (file-> verbose) then it shows
Using Port : \\.\COM14

Using Programmer : arduino

Overriding Baud Rate : 57600

avrdude: Send: 0 [30] [20]

avrdude: Send: 0 [30] [20] <---NOW press the reset once, and hard (atleast on the pro mini) for atleast 100-200ms

avrdude: Send: 0 [30] [20]

psgarcha9228 days ago

Guys, check out my unique experience with this error. Might help you people


JohnN31 month ago

None of this worked for my issue. Here's what I have. I purchased and used an Uno R3 board, and it worked (and still does) quite well. I decided to go the route of building my projects on perf boards thereby saving the Uno for developing new ones. So I bought 5 Atmega 328p PUs, presumably with bootloader installed. To test/verify them I plugged each into the Uno board in place of the original. None worked ! Sketches would not upload with the error

avrdude stk500_getsync() not in sync resp=0x00

I verified each and every item listed, and even tried to load a boot loader, to no avail. The only other differing indication between the original chip and new ones is that the pin13 led would blink several times at power up with the original chip and just come on solid with the power led with the new ones. If anyone knows what's wrong here I'd appreciate any help.

N.fletch (author)  JohnN31 month ago

Right, your explanation of what you experienced is what you should expect. A fresh ATmega328 (and other AVRs) do not come pre-flashed with the Arduino bootloader. That's why you see the pin13 led light up when you have the fresh AVRs plugged in. There are plenty of methods to flash an ATmega328P and other AVRs with the Arduino bootloader and those guides are readily available online and a Google search away.

I respect your choice of developing your own embedded HW applications, I like to do the same thing (and using development boards like the Arduino for quick development). The SW programming for a fresh AVR is lower level, and more difficult than Arduino; but it is much more satisfying and you have a significantly greater understanding of what is happening in the AVR if you ditch the Arduino wrapper.

The best guide I've seen for getting started in embedded design is from Sparkfun here:

Best of luck.

JohnN3 N.fletch1 month ago

Thanks for the reply. Two things come to mind though. 1. The chips were supposed to be and advertised with the arduino bootloader installed. 2 I did try installing the bootloader but when trying to load, I used methods from the arduino (dot) cc website and it didn't work, I simply got more error codes. I only tried the "self clocking" method (with the subject chips on breadboard) so far as I didn't have the 22pf caps on hand, that used the uno as an ISP programmer. All that did is generate more error codes. At this point I am at a loss. Geesh I thought working with the 8080 in the old days with multi-phased clocks was tough.......

I had this issue (except that instead of 0x30 it would show different numbers, including 0x3a and 0x53 if I recall correctly), and it turned out that my issue was that I had the wrong board selected; I was using an Arduino Uno, and I noticed that on the bottom right of my Arduino window, it said "Arduino Mega (ATmega1280) on COM3" (it should have said "Arduino Uno on COM3"). I went to Tools -> Board and clicked "Arduino Uno", and it worked again! So that's another possible issue others could be having.

rhenry91 month ago

I am still getting the above error ... I am running an Arduino Uno from a laptop with Windows 7, I have
nothing in pin 0, My driver agrees with my Arduino selected port (port
5), When I reset my Arduino the little yellow light near pin 13 blinks a
few times and goes out for a few seconds then glows steadily again.

did notice that when I attempt to upload the code, first the light by
pin 13 goes out, then the RX and TX lights blink a few times and
eventually the light near pin 13 glows very dimly ... you have to be in
the dark to see it. HELP please

lugia2 months ago

I got my fixed eventually by removing all connection to input/output pins THEN upload. Uploading has been working well after that.

ZeelP2 months ago

I am facing error: programmer is not responding

xantraxx2 months ago

Qué tal amigos, espero me puedan auxiliar!

Tengo este problema de comunicación con un Arduino Nano, al momento de conectarlo e instalarlo, solamente me lo instala como puerto COM, pero no me lo etiqueta como "Arduino Nano" y al querer programarlo me arroja dicho error. Verifiqué el archivo *.inf de los drivers de arduino y ni siquiera se lista ahí. Este error comenzó desde que instalé la versión BETA1.5.7. Anteriormente tenía instalada la 1.0.6 y trabajaba sin problemas, pero ahora que desinstalé la versión BETA para instalar la antigua, aun así no me jala. Alguien que pueda auxiliarme?

hey guys, I have an ARDUINO PRO MINI and i don't know what driver to install for it, i don't think there is a specific driver for it, or is there? Help please! :(

N.fletch (author)  PeppaQuotaPeeps3 months ago

When you downloaded/installed the Arduino IDE, the driver should be included in the drivers folder. When updating the driver, you only need to select the "Drivers" folder and let Windows pick the driver. At least that's how I did it.

creative_353 months ago

I removed the power(5v) of blue tooth and it worked for me

the same here.

if the bluetooth is connected unplug the 5v.

idawaty.ahmad3 months ago


idawaty.ahmad3 months ago


Thank you very much!!

It was a simple fix for me. COM1 was automatically selected in Ardunio Tools and I had to set it to COM3.

Thank you for the help!!

chearn4274 months ago

Worked for me; great instructable!

ecozcelik4 months ago

Thank you so much !!!

ceeyus4 months ago

Help Please...

I am using a Freeduino board with atmega 8 and i am having this error. I tried installing drivers multiple times , restarted it , tried changing the com ports and even the board (arduino uno to arduino duimilanov) but no avail . only thing i can see is a green light and also there are no issues with the boot loader.

Dave J11 months ago
Thank you for this instructable, I just spent an hour trying to get this sorted out and your instructions got my sketch up and running in 10 minutes.
N.fletch (author)  Dave J11 months ago
Thanks! Glad to hear this guide is still helping people.
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