Hi, I'm new to the forum but have been using Arduino for quite some time. Recently, my arduino micro decided to not show up in the serial port chooser in the tools menu. I am somewhat familiar with the arduino controls and made sure i had selected the right board, my programmer was on arduinoISP and tried pressing the reset many different times in many different patterns. I have never had this problem before and it is really annoying me. I could really use some help. A couple of statistics:
Using arduino ide 1.8.19
on macos monterey on m1 Note: used the ide on m1 for quite some time and have never noticed an issue.
Much appreceation to anyone that could help me. its just not showing up. note: in the available serial port menu there are only two options:
devcu bluetooth incoming port
and
devcu wlan debug
it used to be 3 there was a comm usb modem port which recognized the board attached. trying to locate the problem, I hooked up my uno to the same port and it popped up on the right port. plugged the micro back in and it just wont show. up i though about the cord but i have used the micro with this cord for some time and never had an issue. it was also the cord that came with one of my other adafruit boards so its definately one designed for data transfer.
what operating system are you using?
if windows start the device Manager and open the Ports (COM & LPT)
as you uplug/plugin the Micro USB connector the associated COM port should disappear/appear
I'm not a Mac user so can't tell you where to look but the Mac should recognise a change after the double tap?
Yes to (1) means that the bootloader is working and can be invoked.
Yes to (2) means that you can do an upload as described below
Yes to (1) but no to (2) can be caused by the fact that you're using a charge-only cable.
So if you have yes to (1) and (2)
a) Start the IDE.
b) Open an innocent sketch like blink.
c) Select one of the available ports (e.g. the devcu bluetooth)
d) Start an upload
e) When the IDE reports the memory usage, double tap the reset button.
Regarding (c), if you have an Uno or Mega you can connect that and select its port; keep the target as Micro.
I can provide instructions (this is the macOS equivalent of the "Device Manager" approach mentioned previously by horace):
Click the Apple logo on the left side of the menu bar at the top of the screen ("Apple menu").
Select "System Settings..." from the menu.
A "System Settings" window will open. Click "General" in the menu on the left side of the window. ⓘ You may need to scroll the menu down to see "General".
Click "About" on the panel at the right side of the "System Settings" window.
The "About" panel will open. Click the "System Report..." button at the bottom of the panel.
The "System Information" window will now open. Select Hardware > USB from the tree on the left side of the window.
Take note of the contents of the "USB Device Tree" panel of the "System Information" window.
Press the reset button on the Micro.
You should now see the LED on the board marked "L" pulsing. While it is still doing that, select File > Refresh Information from the menu bar.
Do you see any new device appear in the the the "USB Device Tree" panel of the "System Information" window after doing the last step?
For an Arduino Micro, that might have to be a double tap on the reset. Note that I have a what's next Micro (yes, you may shoot me) that requires the double tap to activate the bootloader.
Unfortunately the bootloader on the official Arduino Micro does not have the feature where a double press on the reset button puts it into a persistent bootloader state, but a double reset has the same effect as a single reset, so I think it is a good idea to do the double reset even if it is not actually needed.
On the official Micro, it only stays in bootloader for ~8 s regardless of whether you did a single or a double press, so it is necessary to be fairly quick about performing step (9) of the instructions after step (8).
Yes. Now I see it under one of the buses labeled Arduino Micro. Thanks for the help with that. However, it still does not show up under ports in the IDE (tools>port):
Yes, the built in led pulsates when reset button is pressed. the mac also recognises it in system information. I tried doing the blink sketch and resetting per your instructions. the IDE still does not recognise the board on the port its on.
I also hooked up my uno, keeping the board selected as the micro. the IDE immediately recognises the uno ( it always has) but then I plugged the micro back in and usb-modem is gone.
It depends on the exact behavior. The instructions I provided before were intended to determine whether the board is recognized at a system level. You have confirmed that. This means we know the problem is not caused at a hardware level (e.g., bad USB cable, burned up board).
When the LED is pulsing after you press the reset button, the bootloader program on the board is running. This is a separate program from the sketch you upload to the board, and has its own code to create a USB CDC serial port. The standard bootloader on the official Arduino Micro boards only runs for approximately 8 seconds, after which time the sketch program runs. Usually an Arduino sketch program for the Micro will also produce a USB CDC serial port (the code for this is in the core, separate from your sketch code, so you don't need to do anything special in the sketch code to create that port), but it is possible for sketch code to disable, break, or interfere with the code that creates the port. In this case, the board will have a port while the bootloader program is running (indicated by the pulsing LED), but no port when the sketch program is running.
You can do another test to see whether the system can see the port while the sketch is running. The instructions are very similar to the ones you already performed. The difference is you should not press the reset button on the board this time:
Disconnect the USB cable of your Micro from your computer.
Click the Apple logo on the left side of the menu bar at the top of the screen ("Apple menu").
Select "System Settings..." from the menu.
A "System Settings" window will open. Click "General" in the menu on the left side of the window.
4.ⓘ* You may need to scroll the menu down to see "General".
Click "About" on the panel at the right side of the "System Settings" window.
The "About" panel will open. Click the "System Report..." button at the bottom of the panel.
The "System Information" window will now open. Select Hardware > USB from the tree on the left side of the window.
Connect the USB cable of your Micro to your computer.
Select File > Refresh Information from the menu bar.
Do you see any new device appear in the the the "USB Device Tree" panel of the "System Information" window after doing the last step?
