The Problem occurs on the Uno r4 WiFi and an ESP32 dev board. Connected via USB-c cable (works otherwise).
Windows 11 latest version
Reinstalled latest Arduino IDE
Uno and ESP32 libraries installed
nothing connected to the boards
It has worked on this PC a month ago. Now i just wanted to get a temp sensor running and it always says ,,no device found" and something about data transmission not possible. I would be very gratefull for any tips or ideas what might be wrong. Thanks!
Use USBDeview to see what happens when you connect your MCU board to the PC. Check whether a new USB device appears at all.
BTW: USBDeview is freeware and does not need to be installed — just unzip and run it.
You seem to be using 3 different COM ports in those screen shots, like you are not sure which is the correct one to use.
It's easy to know which one to use. It's the one that appears when you plug the Arduino in and disappears when you unplug it.
If no new port appears when you plug in the Arduino, that is the real problem.
Please don't post any more screenshots of error messages. An image consumes 10,000x more data than is needed to share the error message. Just select the error message, copy it and paste it into your message, inside code tags.
@siomo123
With USBDeview running, plug the board into the USB port and watch what changes:
| What happens | Next step |
|---|---|
| Nothing changes | Investigate USB/Windows/cable/USB port as the common cause. |
| A USB device appears, but no COM port | Investigate USB enumeration/driver issues. |
| A COM port appears | Select that COM port in the Arduino IDE and try the upload again. If it fails, post the complete upload error message as text. |
Ok, sorry. I just didn't know how it was supposed to look like as it's been a while since I last used it.
There was actually no indication of what port it's connected to and online guides just say one should try then out until one finds the correct one.
How do i go about further hunting down the problem/ solving it?
Please follow the steps in post #4 and tell us which of the three cases applies.
ok so it's case 2. The Uno is registered as ,,Unknown USB Device" and no COM is listed.
Hi @siomo123.
Let's start by focusing exclusively on solving the problem for the UNO R4 WiFi. If we instead try to troubleshoot both boards at the same time, we are likely to get confused and waste time. Once we have achieved a resolution for the UNO R4 WiFi, we can switch our focus to getting your ESP32 dev board working.
Please try this:
The double reset you performed in step (3) can cause the port number of the board to change, so don't assume you already have the correct port selected.Hopefully the upload will now complete successfully. Let us know how it goes.
Nothing changes, the L- LED doesn't even go on.
Hmmm. This is a bad sign. It means that either the bootloader on the board's Renesas RA4M1 microcontroller has been erased, or that the RA4M1 is in a state that causes it to not run the bootloader.
Neither of these things will ever occur under normal operating conditions.
It is possible a short or external circuitry connected to the Arduino board could cause it to be in this bad state.
Make sure the board is not sitting on anything conductive that could short the contacts on the bottom of the board. Do a careful visual examination to make sure there isn't any conductive debris (e.g., loose beads of solder, strands of wire, or component leads) on the board or on the surface the board is sitting on.
If you have a shield or any external circuitry or components connected to your Arduino board, try this experiment:
Now check to see whether a port is shown for the board in Arduino IDE's Tools > Port menu. If not, close the Tools > Port, press the reset button on the board twice (as you did when following the instructions I provided in my previous post), then check for the pulsing "L" light and a port in the Tools > Port menu again.
If the board works as expected after removing the external circuitry, you will know the problem was caused by the external circuitry. You can then focus your attention on identifying the specific problem with the circuit and resolving it.
I checked for anything on the board: no debree, wire etc.. There was also nothing connected to it since the beginning of the troubleshooting.
The problem might be caused by a damaged or defective USB cable. If you have another suitable USB cable on hand, try connecting the UNO R4 WiFi board to your computer with that cable, then check again to see if it is now working.
Make sure the cable is fully inserted into the USB sockets on the board and your computer.
Tried that. Both cables work for data exchange between pc and phone no problem. Still no Com detected
Sadly, I suspect the UNO R4 WiFi board has suffered permanent physical damage. Maybe the other forum helpers will have an idea, but I think it is a lost cause.
I suggest we now switch our focus to trying to get your ESP32 board working.
I'm going to ask you to provide the full verbose output from an attempt to upload to the ESP32 board:
This procedure is not intended to solve the problem. The purpose is to gather more information.
Please do this:
☑ compile in the "Preferences" dialog.<CODE/> icon on the post composer toolbar.```) to your reply to make sure the error messages are correctly formatted.
Sketch uses 254936 bytes (19%) of program storage space. Maximum is 1310720 bytes.
Global variables use 22100 bytes (6%) of dynamic memory, leaving 305580 bytes for local variables. Maximum is 327680 bytes.
"C:\Users\Simon Ruhland\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.3.11\tools\flasher.exe" --esptool "C:\Users\Simon Ruhland\AppData\Local\Arduino15\packages\esp32\tools\esptool_py\5.3.1/esptool.exe" --build-dir "C:\Users\Simon Ruhland\AppData\Local\arduino\sketches\AB44B34BC6BFC52C0D13401C53977584" --chip esp32 --port "COM1" --baud 921600 --before default-reset --after hard-reset write-flash -z --flash-mode keep --flash-freq keep --flash-size keep 0x1000 "C:\Users\Simon Ruhland\AppData\Local\arduino\sketches\AB44B34BC6BFC52C0D13401C53977584/sketch_aug11a.ino.bootloader.bin" 0x8000 "C:\Users\Simon Ruhland\AppData\Local\arduino\sketches\AB44B34BC6BFC52C0D13401C53977584/sketch_aug11a.ino.partitions.bin" 0xe000 "C:\Users\Simon Ruhland\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.3.11/tools/partitions/boot_app0.bin" 0x10000 "C:\Users\Simon Ruhland\AppData\Local\arduino\sketches\AB44B34BC6BFC52C0D13401C53977584/sketch_aug11a.ino.bin"
esptool v5.3.1
Serial port COM1:
Connecting......................................
A fatal error occurred: Failed to connect to ESP32: No serial data received.
For troubleshooting steps visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html
Failed uploading: uploading error: exit status 2
Ok, that's unfortunate, but thank you all for the diagnosis on the UNO.
@ptillisch I followed your steps for the ESP32 and on top is the Error Message. Hope that helps
This error might be caused by having the wrong port selected from the Tools > Port menu in Arduino IDE.
Please perform this experiment to verify that the port you have selected is your Arduino board:
The ports list is only updated when the Tools menu is re-opened, so this step is essential.If you saw a new port appear at the last step, select that port from the Tools > Port menu and try uploading again.
If this doesn't solve the problem, please reply here on this forum topic with the answers to the following questions:
No, no Port appears. It's always just COM1/3/4
Please try this troubleshooting procedure and then report the results:
This procedure is not intended to solve the problem. The purpose is to gather more information.
Now please reply here on this forum topic with the answers to the following questions:
You can repeat the procedure multiple times if you are not sure.
ⓘ You can use USBDeview instead of Device Manager if you prefer. I chose Device Manager when writing the above instructions only because this is something all Windows users will have access to without installing additional software.
Yes, it is listed as "CP2102 USB to UART Bridge Controller" under "Other Devices"
Nothing under "Ports(COM&LPT)
OK, you should be able to fix this by installing the driver provided by Silicon Labs, the manufacturer of the CP2102 USB chip on the board. You can download the driver from the manufacturer website here: