Serial Port already in use AND Serial Port greyed out.

I have an Arduino UNO that was working fine on Ubuntu several weeks ago. I was only on basic tutorials, but the sketches all uploaded fine. Since my Ubuntu crashed, I’ve been trying to get Arduino going on Windows 7.

I’ve been trying to upload the “blink” example sketch, but I keep getting “Serial port COM3 is already in use…” as an error. I’ve been trying everything I could find on these forums. Typically, I keep reading some combination of the following:

  • uninstall/re-install arduino software
  • uninstall/re-install drivers
  • restart computer
  • press and hold down reset button in some special fashion

I’ve tried all of these things (except re-installing the Arduino software). Nothing has worked! Also, whenever I press the reset button on my UNO, the “Serial Port” menu gets greyed out.

Is there any other special advice I should follow? Is there a more elaborate way to reset the Arduino that I’m not following (involving the battery and the ground)?

Thank you.

And as a quick addition:

During most of the things I've tried, I've kept the Arduino plugged into the computer...so when restarting the computer, uninstalling/re-installing, etc. I've kept it plugged in.

When you plug & unplug the Arduino does the COM port appear & disappear in the Device Manager list? Is something else already using COM3 (Device Manager)?

Unplug the Uno when you're installing/un-installing.

Carthaginian: Also, whenever I press the reset button on my UNO, the "Serial Port" menu gets greyed out.

This is a red flag since pressing reset has nothing to do with the ATmega8u2 chip acting as the serial to usb converter.

Carthaginian: Is there a more elaborate way to reset the Arduino that I'm not following (involving the battery and the ground)?

Wait, Battery?

You said you were using an Uno. Where does a battery come into play?

[quote author=Runaway Pancake link=topic=182182.msg1350343#msg1350343 date=1376264574] When you plug & unplug the Arduino does the COM port appear & disappear in the Device Manager list? Is something else already using COM3 (Device Manager)? [/quote]

When the Arduino is unplugged, the COM port does disappear from the Device Manager list. Does that imply nothing else could be using the port?

Unplug the Uno when you're installing/un-installing.

...when un-installing/re-installing what in particular?

[quote author=James C4S link=topic=182182.msg1350379#msg1350379 date=1376271052] Wait, Battery?

You said you were using an Uno. Where does a battery come into play? [/quote]

I meant to say "using a battery", but really, I was referring to something like this: http://forum.arduino.cc/index.php?topic=92148.0 .

[quote author=James C4S link=topic=182182.msg1350379#msg1350379 date=1376271052]

Carthaginian: Also, whenever I press the reset button on my UNO, the "Serial Port" menu gets greyed out.

This is a red flag since pressing reset has nothing to do with the ATmega8u2 chip acting as the serial to usb converter. [/quote]

On closer examination, this isn't happening. Rather, it "greys out" whenever I unplug and re-plug the Arduino. The problem happens as follows:

  1. I start the IDE / Arduino plugged in => Serial Port is greyed out
  2. I uninstall COM3 driver / still plugged in (if I wasn't plugged in wouldn't be visible and I wouldn't be able to uninstall the driver)
  3. I restart computer / still plugged in
  4. Windows automatically installs same COM3 driver over again / still plugged in
  5. I start IDE / still plugged in => Serial Port is now visible
  6. I unplug Arduino => Serial Port is greyed out again
  7. I stop/restart IDE, unplug/re-plug Arduino, etc. => Serial Port remains greyed out

At this point, Serial Port remains greyed out until I uninstall COM3 again.

http://www.hobbytronics.co.uk/arduino-installation

[quote author=Runaway Pancake link=topic=182182.msg1350806#msg1350806 date=1376311833]

http://www.hobbytronics.co.uk/arduino-installation [/quote]

What specifically haven't I done yet? (also, these instructions are old)

To repeat myself, the only thing that appears in my Device Manager's Port listing is the Arduino Com port. When the Arduino is not plugged in, the Device Manager doesn't even have a Port list.

Is there anything connected to the Arduino? Are you connecting through a hub?

[quote author=James C4S link=topic=182182.msg1350973#msg1350973 date=1376321860] Is there anything connected to the Arduino? Are you connecting through a hub? [/quote]

Uno. USB. My laptop.

On XP --

  • I plugged in a Uno and waited for it to "fail"
  • I got into Control Panel, got into device manager and right clicked on the Arduino Uno (it was Question Marked) a selected Update Driver
  • In the Wizard I clicked the radio button for Browse my computer and waded down the folder tree (the Arduino root) till I got to the Drivers folder (you won't see arduino uno.inf in a list_*_)
  • I went with 'OK' and/or 'Next' when prompted from there and on

I'm sorry that this has been such a pain for you.

The device the Uno has in place of the FTDI used previously is a programmable device. But it cannot be casually reprogrammed

* You can find it by Searching for it or by opening the folders till you find it.

Carthaginian: [quote author=James C4S link=topic=182182.msg1350379#msg1350379 date=1376271052]

Carthaginian: Also, whenever I press the reset button on my UNO, the "Serial Port" menu gets greyed out.

This is a red flag since pressing reset has nothing to do with the ATmega8u2 chip acting as the serial to usb converter.

On closer examination, this isn't happening. Rather, it "greys out" whenever I unplug and re-plug the Arduino. The problem happens as follows:

  1. I start the IDE / Arduino plugged in => Serial Port is greyed out
  2. I uninstall COM3 driver / still plugged in (if I wasn't plugged in wouldn't be visible and I wouldn't be able to uninstall the driver)
  3. I restart computer / still plugged in
  4. Windows automatically installs same COM3 driver over again / still plugged in
  5. I start IDE / still plugged in => Serial Port is now visible
  6. I unplug Arduino => Serial Port is greyed out again
  7. I stop/restart IDE, unplug/re-plug Arduino, etc. => Serial Port remains greyed out

At this point, Serial Port remains greyed out until I uninstall COM3 again. [/quote]

Go into Device manager on the PC and in the comms port list right click on the serial port and disable it. It will give you a warning about needing to restart - ignore it.

Make sure you do not have the serial monitor or IDE running.

Then in device manager - re-enable the device.

You probably have Phantom devices on the machine that are giving you grief.

Report back if this resolves it and i will show you how to delete hidden devices

Craig

Some good news today. I tried out the board and cable on a friend’s Mac, and it worked fine (and as I mentioned earlier, it worked fine when I had Linux). I’m now confident that it really is Window’s fault.

As for Sysinternal, I’ve gone to this page http://technet.microsoft.com/en-us/sysinternals/bb963902 . However, it now seems to me that “Sysinternals” names a whole collection of software, not just what I need. What more specific software should I be using?

And as a final note, I tried the “disable/re-enable” strategy with no luck. Thanks though for the suggestion.

Carthaginian: Some good news today. I tried out the board and cable on a friend's Mac, and it worked fine (and as I mentioned earlier, it worked fine when I had Linux). I'm now confident that it really is Window's fault.

As for Sysinternal, I've gone to this page http://technet.microsoft.com/en-us/sysinternals/bb963902 . However, it now seems to me that "Sysinternals" names a whole collection of software, not just what I need. What more specific software should I be using?

And as a final note, I tried the "disable/re-enable" strategy with no luck. Thanks though for the suggestion.

A combination of these two should give you plenty of info

http://technet.microsoft.com/en-us/sysinternals/bb896653

http://technet.microsoft.com/en-us/sysinternals/bb896645

regards

Craig