[solved] DFU Mode Arduino UNO without soldering

Hi all, I've just bought an arduino UNO a week ago (more or less) and I'm very happy to explore/study electronics using it. I'm using version 0022 IDE on Ubuntu 10.10. I can upload sketches without problems and everything is working as expected. I got just one problem: when I loaded DigitalReadSerial I wasn't able to use the board any more. TX led always on and all the rest... Yes, I know, it's a known bug and there is also a fix but there is a very difficult fix to apply for me. I have no experience at all in soldering but now it seems like I'm forced to solder a 10k ohm resistor on the backside on my board... Now I've solved loading an empty sketch from Windows so I can test/program/study without problems everything but the serial module. Is there a way to upload the new usbserial firmware without soldering the board?

Thank you!

This worked for me. See Reply #10 http://arduino.cc/forum/index.php/topic,52076.0.html

Instead of soldering a 10K resistor, you can hold a piece of wire against the two pads that you’re meant to solder the resistor on. While holding that wire in place, briefly connect and then disconnect the two pads of the 6-pin header next to the 8U2 shown in the tutorial http://arduino.cc/en/Hacking/DFUProgramming8U2 (reset and ground). Then, release the wire that you’re holding against the two pads on the back of the board. This should put the board in DFU mode. It requires a bit of dexterity, but no soldering.

ok. I solved! thank you guys!! for everyone looking for the same solution I'll write my steps: ps: I did these steps after I loaded and "empty" sketch to the board from a windows machine.

void setup(){}
void loop(){}


$ sudo aptitude install dfu-programmer


$ wget --no-check-certificate https://github.com/arduino/Arduino/raw/master/hardware/arduino/firmwares/arduino-usbserial/Arduino-usbserial-uno.hex $ md5sum Arduino-usbserial-uno.hex 8e01ee236e70bbea43f7eb4e11c9688a Arduino-usbserial-uno.hex


0) connect your board to the pc 1) hold the first wire on the top left 8u2 ICSP pad 2) touch the second wire against the left side of the capacitor below the RX LED (leds will blink) 3) remove the second wire 4) remove the first wire

UPLOAD THE NEW FIRMWARE (console commands)

$ sudo dfu-programmer at90usb82 erase $ sudo dfu-programmer at90usb82 flash Arduino-usbserial-uno.hex $ sudo dfu-programmer at90usb82 reset


disconnect the board from the pc reconnect it and have fun ;)

thank you MementoMori and all that helped on this problem your post fixed my uno board, the only diffrence was i did the upgrade you outlined before loading the blink.pde and i had the same problem untill i loaded arduino 0022 on xp and then loaded blink.pde after i did that it was fine thank you


I just opened the box tonight, correctly followed the arduino ide install directions, uploaded 1 sketch, then ran into this problem.

It seems like this post should be linked the Ubuntu issues (ppl might not make the connection with DFU), and on the arduino download instructions site http://arduino.cc/playground/Linux/Ubuntu .

Also probably pushed to the deb repositories, and given as a howto on the ubuntu forums. Now, back to the good stuff!

So basically, the Arduino just needs new firmware to solve this issue?

yess Good Thank Fro you SoMuch info! :0 :0


As I understand it is was just the first batch of Uno's that had this issue, though I'm sure they will keep surfacing for a while as suppliers shift the units. Hopefully next time a major hardware change is released they will actually test on Linux.... ;)

the git hub repo has been reorganized. the current wget command is:

wget --no-check-certificate https://github.com/arduino/Arduino/blob/master/hardware/arduino/firmwares/atmegaxxu2/arduino-usbserial/Arduino-usbserial-uno.hex md5sum Arduino-usbserial-uno.hex
3d071dd434daef235b9a373511fe75aa Arduino-usbserial-uno.hex