the board is in bootloader mode when it fades like that.
a subsequent upload should be able to just see it and deal with the upload.
I am not able to reproduce the error anymore after un installing/reinstalling the core
do you get this dialog at the end of the core installation?
With the board in bootloader mode, a subsequent upload also fails.
I did get that dialog. I responded Yes
Don
I had the same issue and this worked for me. With Arduino IDE 1.8.19, i'm able to upload sketches to the board.
@ubidefeo I didn't get it to work after doing this. It seems to be in bootloader mode (the led is slowly turning on and off).
I asked the members of my team to take a look and I'll keep you posted on this
out of curiosity:
who here is part of the early access program and had preview index access?
Hi. I just found a possibly related issue with my brand new R4 WiFi (and I am part of the early access program).
I tried to upload a sketch using my usual MAC, and I got
Failed uploading: no upload port provided
I noticed that the port to which the Arduino was attached was not in the list of available ports, but when I pressed the reset button it appears for few seconds, then disappeared again.
I could upload the sketch as follows:
Since this episode, I had no more problems in uploading. The latter started after I uploaded the sketch provided as an example in the LED matrix, but I cannot say if this is correlated to the problem or not.
Same problem on mi new R4
No device found on COM7
Failed uploading: uploading error: exit status 1
Same here!
When I use the old Arduino version (1.8) I can upload programs to the Arduino UNO R4 WIFI.
When I disconnect from 1 pc (with old version) to a pc with the new version, it doesn't work at all.
Always the same problem (no device found on COM3).
I guess it's a problem with the 'new' arduino IDE version?
Kind regards
Does not work in the new or legacy IDE for me.
An update from the internal team:
the issue is caused by how the board is reset and put into bootloader mode.
In IDE 1.8.19 the serial port opening/closing (touch at 12bps) is handled in Java using Java bindings to Serial ports.
For IDE 2 we rely on the Arduino CLI using the OS bindings of the hardware.
Unfortunately this doesn't seem to happen to every Windows user, and it's not consistent until it first happens.
it has happened to me yesterday but this morning it worked, and in the afternoon I had the issue again.
we're looking into solutions, but we might have to rework how the CLI establishes a serial connection.
please bear with us as we strive to get a working solution into everyone's hands
thank you
u.
I have the same issue, except i tried using the CLI version with VS Code and the Web-editor.
@ubidefeo Thank you so much for your rapid response on this. It is very much appreciated. I teach a couple of courses which use microcontrollers (one course uses the Mega 2560 and the other uses the ESP-32), and am hoping the Uno R4 WiFi will be a common system for both and future courses, saving both my department and, most importantly, my students, time and finances.
Best regards,
Chris
And now we wait.I have such a urge to program this and play with the led matrix and use all that code space. If someone finds a solution pls share.
hey Chris
we try to do our best to support users.
your use case seems to be exactly why we created this board 
hope to have a solution soon, we have a few heads digging into this issue.
it's a pity it didn't really show up in internal testing, and we did not provide the WiFi to our preview users until just a couple days ago.
Fingers crossed we'll iron it out by next week 
I'm also itching to see what people do with the matrix.
it was fun to work on it.
I wrote the matrix editor engine and did some work on the library.
The editor's got a couple bugs but as a Lab project it's developed on a voluntary base so a few of us came together to make it during our hacking afternoons
UPDATE: i have installed .rar IDE v 1.8.18 and I can upload code using it .
same problem when ide is 2.1.0
No device found on COM3
Failed uploading: uploading error: exit status 1
I was thinking of using the LED matrix to display something like displaying magnetic field strength in an intensity view, so my students can say they've detected a metal object using a magnetometer.
+1 windows user with all the above symptoms when trying to upload sketches using IDE v2.1.0
