






I was having this same problem and it was driving me nuts. I had tried installing 1.5.2 on three different machines (XP, 2x Win7), re-installing 1.0.5 and loading code to a 2560, rebooting multiple times, replacing the 16U2 firmware (2 other versions), different USB cables - but nothing worked (except manually erasing and resetting the board).


THEN, I read the post from Aiekakiku http://forum.arduino.cc/index.php?topic=168399#msg1279303 and decided to try it. I shorted out R23 with a small flat blade screwdriver (pressed on the side of R23).

It worked!

I then soldered a short across R23 - and it has continued to work on both my Win7 and XP machines, every time. The short is not the safest solution and I will try a 1K resistor as a permanent fix.

So this appears to be a design flaw in the DUE. R23 is the wrong value. Specifically, natural variation of R23 and the 15K pull-up on the SAM3X can result in inadequate margin to the input threshold (Vil) of the NRSTB signal on the SAM3X. This means some systems work OK, some are intermittent and others fail all the time.


Many thanks to Aiekakiku for his original post.


Is R23 still incorrect on the Due R3 board?

(could just be soldered in parallel with the existing resistor)


UPDATE on R23:
I confirmed that changing R23 to 1K does correct the “No device found on COMxx” problem.


However - changing R23 value has an unintended consequence:

I’m not sure why this occurs, but it is very repeatable.


	TCNT0 = 0;
	TCCR0B=0;  // Stop the counter
	TCNT0 = 0;  // re-init timer count



So in summary:



Arduino-DUE-usbserial-prod-firmware-2013-02-05_resetfix.hex (11.9 KB)

what if your solution doesn't work for me? i changed r23 to 1k and uploaded the firmware you attached but the ide still tells me "No device found on COM"

@aureliusss: Sorry to hear that it did not work for your board. I assume that you are trying to connect to your custom built Due board? (From your posts in http://forum.arduino.cc/index.php?topic=181680.msg1381529#msg1381529)

Note that the R23 fix and the 16u2 firmware fix are intended for Due boards where you can press the reset button to manually fix the "No device found on COMx" error. If your system is not recognized by the IDE when trying to download after you press the reset button - there is likely something else wrong.


Sometimes, if the PC is recognizing your Due's Programming Port, you just need to completely close and restart the IDE program.


I get that Arduino is for the DIY crowd, but it seems off to me that I should have to short a resistor to get it to do what's advertised. If this is a problem with the board, should this not mean fixing the problem and then recalling/replacing the boards?

I keep running into this problem, and unplugging and re-plugging my board seems to fix the issue. But, after doing it 30 times in an hour I'm starting to notice that the usb port is getting a little wiggly. At this rate, no doubt that port is going to fall off.

Admins? Is this a known hardware problem?

Cheers, Mike

we change the R23 to 1K, but it didn't work. Is there anyone solve the problem with this?


I feared this too, so during development I unplug the other end of my USB cable from the PC to save wear on the Due.

Unfortunately, because of Apple and all of their wisdom, my usb port is on the back of my computer, make it kind of difficult to access.

Admins / Arduino staff - is this a known problem and, if so, are you going to fix it?

Cheers, Mike

Hi all,

The correct value for the R23 resistor is 1k ohm. R23 resistor is used to adapt the 5V logic of the 16u2 to be compatible to the voltage logic of the SAM3x, the 10k ohm gives completely wrong values to the reset pin.
I want to figure out if it happened a mistake during assembling.

Can I ask to those of you who have experienced the problem to write me the serial number of the Due, you can find on the cardboard box?
You can reply here or write me an email (f.vanzati at arduino.cc)

NB: the serial number is not the number written below the bar code, is on a separate sticker.


Is there another way to give you the serial number? My wife threw away the box and any associated stickers.


Unfortunately there isn't another way to go back to the serial number. Can you send me a picture and possibly the invoice of the distributor where you purchased the board?

cheers Federico

It makes zero sense to put the serial number on the box but not the board. Exactly for this reason.



This is a bit silly to have to post this, but here we go (see attached).


Thank you Mike, I meant to sent me the things I requested via email to the email I provided in the message above. I'm sorry for not having specified again I removed the invoice attachment contained in your reply.

We are checking the last batch of Due produced. I'll be able to answer in the coming days