DFU-port not working for Arduino Uno and Arduino Uno R4 minima

Hardware UNO R4 UNO R4 Minima
1

Hello,

I coming back on the DFU-port not working for Arduino Uno and Arduino Uno R4 minima (to be sure that there is no problem with one of the Arduino device). The message is the following:

“No DFU capable USB device available - Failed uploading: uploading error: exit status 74”

I tried th e command “cd "${Env:LOCALAPPDATA}\Arduino15\packages\arduino\hardware\renesas_uno\1.0.4"; & ".\post_install.bat"”.

It makes the DFU 4 installation, so it’s great but nothing changes on the DFU. Nothing appearing in the device manager, like explained in the forum.

I have the same problem on Windows 11 and Windows 10, two different PC - they both are up to date.

It was working before but I didn’t used the Arduino for 2 weeks and now it’s not working. So my interesting project which was working is going south.

I do not see any working solution on the forum.

Can you help me?

Thanks

1 Like
2

let's focus on Minima. DFU mode on Uno R3 is only for the ATmega16u2, which servers as USB adapter.

what do you want to do with the DFU mode on Uno R4 Mninima. do you wan to burn the bootloader?

or you just try the upload a sketch and you get that error? did you try the double reset to activate the bootloader?

1 Like
3

Hello I have this error when uploading the sketch. Yes I tried the double reset.
Thanks

1 Like
4

This might indicate a bad cable or bad USB port. Try different cables and ports.

1 Like
5

Thanks

I used two different Arduino (Arduino Uno and Arduino uno R4 minima), on both it’s the same problem. They have different USB cable. And I tried on 2 different Windows PC. So all the basic have been eliminated.

I tried on a 3rd Windows PC without any Arduino IDE previously installed. At first the Arduino uno was reachable on the com port. To use the Arduino uno R4 minima I had to add the Arduino uno R4 minima software package. It reinstalled the DFU-port.

And then both of them was not working.

I seems to be problem with the driver on Windows. I think a security one.

Do you have an idea?

Thanks

1 Like
6

I removed all the boards in “board’s manager” and reinstalled only “Arduino uno R4 minima”. The status is:

  • Serial port on Arduino Uno is seen as connected on the IDE, but when I upload a simple sketch “No DFU capable USB device available Failed uploading: uploading error: exit status 74”
  • Serial port on Arduino uno R4 minima is not working on the IDE. May be the “Arduino uno R4 minima” is not working any more.

Thanks

1 Like
7

as expected with Uno R4 selected in Tools menu

try the double reset again

8

Nothing happens after the double reset, no port discovered.
Thanks

9

What should happen with the double rest?

10

the L LED should pulsate. try the upload even if no port is available

11

Yes, the LED pulsate. However, when I try to upload a sketch I always get “No DFU capable USB device available Failed uploading: uploading error: exit status 74”. The port is unavailable. Not simple!
Thanks

1 Like
12

Hello where to get a solution to this problem? They are a lot of other people relating this situation. Thanks

1 Like
13

I solved it waiting for the serial port to finish start

void setup() {
   Serial.begin(9600);
   while(!Serial){}
  // put your setup code here, to run once:
  
  

}
1 Like
14

Summarizing how I solved the problem.
The problem in my case started when I loaded a sketch that used the serial port. After loading that sketch, the USB driver no longer loaded.

image
image840×720 72.4 KB

To solve it:
First press the reset button twice. In this way, from the Arduino IDE you can now find the Arduino R4 Minima attached to a DFU port.
Load an LED blink sketch that does NOT use the serial port.
After loading that sketch it should now load the Arduino Minima as a serial port.
Check with the device manager if the port created has any problem, in which case solve the problem by updating the driver, you may have to select between two drivers, do not choose the one called Santiago.
image
image925×1146 106 KB

Now remember that whenever you use the serial port in the setup, after starting it wait for it to be ready. while(!Serial);

void setup() {
   Serial.begin(9600);
   while(!Serial){}
  // put your setup code here, to run once:

}
15

I posted a blog with the steps I followed and how I solved it in case it helps someone else. I also include how I reflashed the bootloader, although that does not solve the problem.
[https://community.element14.com/products/arduino/b/blog/posts/arduino-uno-r4-minima-troubleshooting-unknown-usb-device](https://Arduino UNO R4 Minima - Troubleshooting "Unknown USB Device: Device Descriptor Request Failed ")

2 Likes
16

@javagoza I am so glad I've found your workaround! Though in my case it seems nothing to do with using Serial in sketch. Even if I completely remove it, I still get my R4 Minima Serial port disappear as soon as I start uploading sketch.

I am using Mac OS with Arduino IDE 2.2.1, and running ls /dev/tty.* and ls /dev/cu.* in Terminal doesn't list Serial port of my board. IDE, of course, doesn't see it either. Only after I upload standard Blink sketch through DFU mode after double reset, the port is visible again. But disappears as soon as I try to upload sketch I've been working on.

UPD: In my case it was error in sketch (I was trying to dereference nullptr pointer).

1 Like
17

FWIW I have been pulling my hair out with this problem recently.

After a lot of basic trouble shooting, changing cables, plugging into different USB ports on the computer etc and the above useful discussion I "think" I have fixed it for my situation.

Here are my notes in case they can help someone:

Port problems with uploading Arduino sketches to UNO 4 etc

  • Disconnect UNO R4
  • Reboot computer
  • Connect battery power to UNO R4 [avoiding any computer port issues].
  • Double click the reset button [LED “L” pulsates to indicate this state].
  • Open Arduino IDE
  • Open the BLINK example.
  • Connect UNO R4 to computer with USB-C cable.
  • Under Tools\Board choose UNO R4
  • Under Tools\Ports choose “1-4 (Arduino UNO R4 Minima)”. [The top line in the menu will say “dfu ports”]. The IDE will say “Arduino UNO R4 Minima on 1-4” in the green area at the bottom of the screen.
  • Upload BLINK example [because it doesn’t have any Serial.print commands] and see the LED blinking. The IDE will now say “Arduino UNO R4 Minima on COM6” in the green area at the bottom of the screen and the Tools\Port now shows COM6.

I was able to successfully upload it several times, changing the blink delay times and seeing it change.

DFU-RT Port now shows in the Device Manager\Universal Serial Bus devices [there was some discussion about NOT using the Santiago one].

[COM6 is what my computer was choosing, yours could be COM8 etc.]

Curly_Bracket

18

Hi all,
No chance to download.
I am running Arduino IDE Appimage on ubuntu 18.04
Following step by step, I am not able to choose the port while the Arduino is in DFU mode, non port available.
Of course, upload failed immediately.
As soon as I reset the board, the port is available, however I catch also the error.
I read Javagoza on element14 forum but was not able to find out the trick to apply on my computer.
Any idea ?

19

On DFU mode a port doesn't matter, PC will search dfu device on all available ports.
See how I manage DFU download with stm32 boards:

  1. Prepare the board with cable, but do not connect it to PC.
  2. Start upload process in IDE.
  3. Wait until compilation finished and IDE write something like "Search for DFU device...."
  4. Connect the board USB cable to PC
1 Like
20

Hi All,

I know I am bit late with the topic, but I just struggled with it. While searching, I saw a lot of people write that the method of resetting by double clicking did not work. For me, it was because I did not press it fast enough. So not its not "tap tap" but rather "taptap" :slight_smile: