I just got a Tiny Machine Learning Kit. The first day it worked perfectly fine and I uploaded the blink example to it. The next day, when I tried to plug it into a USB port on my PC, it only showed for a second and then disappeared. What should I do?
Hi @coolcoder1. Press and release the reset button on your Nano 33 BLE Sense Rev2 board quickly twice. After that, does the board show as expected?
Yeah, it worked. Thanks for the advice!
You are welcome.
The tricky thing about the boards with native USB capability like your Nano 33 BLE Sense Rev2 is the USB code that creates the CDC serial port is running on the same microcontroller as your sketch. This means your sketch code can break the USB code, or stop it from running. When that happens, it no longer presents a port.
This can be unexpected to those who previously mainly worked with the boards like Uno and Mega with a dedicated USB chip that can never be affected by the sketch code.
If you still need to do the reset trick to do uploads after this, the problem may be caused by your code. You can verify this by uploading a simple sketch like File > Examples > 01.Basics > BareMinimum. If the uploads work normally after uploading that sketch, but not after uploading the previous sketch you were using, then you will know the issue is caused by that other sketch code.
The loss of the port is an expected result of some programs. In this case, you will need to do the double reset each time before an upload.
In other cases it may be caused by a bug in your code. But now that you know the technique for restoring the board to a functional state, you should be able to troubleshoot the code and fix the bug.
Ok. Thanks!
Hey, ptillisch. So, the double reset worked yesterday, but today the board still won't show up as a port even after the double reset. Is there something else I can do or should I just return it?
Does the LED on the board that is marked "L" pulse after you perform a double reset?
Yeah, it does. Why?
This shows that the microcontroller on the board is functional and the bootloader is present.
Make sure the USB cable is completely plugged into both the Arduino board and the PC.
If that doesn't help, you may have a damaged/defective or charge-only USB cable. Try a different cable.
Either of the above can result in the power connections being made (and thus LED lights on the board), but no data connections (and thus no port for the board).
Which operating system are you using (e.g., "Windows")?
Yeah, I use windows.
Did you check the USB cable? That is the most common cause of the symptoms you describe. If you find that the USB cable is not the cause, I can suggest something else to try.
Yeah, I used a different chord and it worked.
I'm glad it is working now. Thanks for taking the time to post an update!
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