Avrdude error prohibits upload which worked before

[fritzbauspiess]

Dear community, I need your help!

I cannot upload any program to my new Arduino Uno Wifi Rev.2 anymore - even not a program which already worked. I did extensive research in the Web and here in the forum but did not find any solution yet.

Here is what I did:

I purchased a new Arduino Uno Wifi Rev.2 board and started with a simple Blink program/sketch with the onboard LED. No external electronics attached - just the pure board connected to my laptop via USB cable, no additional power supply but power via the USB. This Blink sketch compiled, loaded and worked fine and I was happy

Next, I wanted to try the onboard RGB LED, read somewhere that this would require the Wifi libraries, loaded them and tried. Unfortunately no success. Instead the below avrdude errros started to occur.

So I wanted to revert back to my first sketch which I knew was working. But now I receive the same error there as well. Whatever I try, the compilation and check is fine (not really a surprise as the code worked initially) - but the upload fails.

These are the error messages which occur in the "Output" window in my Arduino IDE 2.1.0:

Der Sketch verwendet 3157 Bytes (6%) des Programmspeicherplatzes. Das Maximum sind 48640 Bytes.
Globale Variablen verwenden 183 Bytes (2%) des dynamischen Speichers, 5961 Bytes für lokale Variablen verbleiben. Das Maximum sind 6144 Bytes.
avrdude: Short read, read only 0 out of 64 bytes
avrdude: jtag3_edbg_recv(): Unexpected response 0x12
avrdude: retrying with external reset applied
avrdude: jtag3_edbg_send(): Unexpected response 0x81, 0x11
avrdude: jtag3_edbg_recv(): Unexpected response 0x80
avrdude: retrying with external reset applied
avrdude: JTAGEN fuse disabled?
avrdude: initialization failed, rc=-1
         Double check connections and try again, or use -F to override
         this check.

avrdude: jtag3_edbg_send(): Unexpected response 0x81, 0x11
avrdude: jtag3_edbg_recv(): Unexpected response 0x80
avrdude: jtag3_edbg_send(): Unexpected response 0x81, 0x11
avrdude: jtag3_edbg_recv(): Unexpected response 0x80
avrdude: jtag3_edbg_signoff(): unexpected response 0x81, 0x11
avrdude: jtag3_edbg_signoff(): unexpected response 0x01, 0x00
Fehlgeschlagenes Hochladen: Hochladefehler: exit status 1

I have the impression that I somehow may have killed the bootloader on the board, so I tried in the IDE: Tools --> Burn Bootloader ... which interestingly lead to the exact same error messages as copied above.

Looks for me like a communication problem with the board which prohibits any type of uploading.

I powered down the board and the laptop, removed and reinstalled the IDE, removed and reinstalled the specific libraries within the IDE - nothing works, always the same error messages.

Interestingly, the IDE correctly identifies the board with the correct board name and type - putting it in bold when I plug in the USB and revert it to simple when I unplug it. Also the COM port is correctly identified. So, some communication seems to work but beyond that I am not able to do anything with the board.

Any hint you can help me with?

Best regards, Fritz

[Juraj]

try to hold the reset button until the upload starts

[fritzbauspiess]

Hi Juraj,

Thank you for your response!

try to hold the reset button until the upload starts

Ok - this was surprisingly simple!

In fact, I tried it several times without success with different timing until I discovered that I have to release the reset button as short as possible >before< the upload starts while it failed as long as I tried to release it immediatly >as soon as< the upload started.

Thank you so much!!
This solved my problem and I can continue!

Just since I am curious: Any idea what happened?
(only if you have a few minutes of additional time to guide me into more mysteries of the Arduino :-))

Best regards,
Fritz

[Juraj]

in my experience this happens when the sketch floods Serial.

[fritzbauspiess]

Interesting!
Thank you so much for the information and for your fast help!
Best regards, Fritz