Serial Port 'COM3' already in use.

My arduino does not connect to my computer. I get the error "Serial Port 'COM3' already in use. Try quitting any programs that may be using it." This happens even on a fresh restart.

How do I fix this?

Are you sure that you have the right COM port? And what Arduino do you have?

baum

in the arduino editor select:

Tools/Serial Port/Com5

unplug your arduino, restart the editor, then plug your arduino back in. hope that helps.

Mega.

Yes, correct serial port is selected hence it says that the serial port is occupied.

Can we assume that I've done everything right, and this is only about getting the two to communicate.

Have you installed the FTDI drivers or the atmega8u2 .inf file? If not, windows may think that the mega is something else...

baum

emilyskopp: Yes, correct serial port is selected hence it says that the serial port is occupied.

Or maybe it's occupied by another device, like bluetooth.

I usually get that message when I open a serial port (in another programming language) and don't close it. There could be other programs that scan all serial ports (looking for bluetooth devices, for example) and don't end up closing them. What's your operating system?

emilyskopp: Can we assume that I've done everything right, and this is only about getting the two to communicate.

Oh, you've done everything right? Okay, don't need our help then.

My computer doesn't have Bluetooth. Windows 7.

I've done this before on Linux. It worked like a charm. Now I have a new computer on Windows 7.

I have done everything correctly. Don't judge. I just can't control which ports are being used by which devices.

What if you change ports? you do have >1 USB port, right?

If port is in use, open the Device manager, disable port and then enable port. This unlocks the port.

K5CZ: If port is in use, open the Device manager, disable port and then enable port. This unlocks the port.

Just a quick note (since I'm having a similar problem). When I disabled the port, I had to restart the computer before it would be enabled again. Once the computer rebooted, nothing different happened. It didn't work.

Maybe this solves your issues http://forum.arduino.cc/index.php/topic,118440.0.html (old avrdude left my port in use with some cheap mega2560 clones)

The OP and I are dealing with a similar problem, and we have at least one thing in common:

We originally used our boards with Linux. Everything worked fine then. Then we moved to Windows 7 (and I assume with the same boards) and started having problems.

At least in my situation, could Linux have messed with the ports? Any other ideas?

eried: Maybe this solves your issues http://forum.arduino.cc/index.php/topic,118440.0.html (old avrdude left my port in use with some cheap mega2560 clones)

I tried this other software and got the same error.

Carthaginian:

eried: Maybe this solves your issues http://forum.arduino.cc/index.php/topic,118440.0.html (old avrdude left my port in use with some cheap mega2560 clones)

I tried this other software and got the same error.

mmm so I think your problem is another application running in your machine. I can try to help you if you want via teamviewer

eried: mmm so I think your problem is another application running in your machine. I can try to help you if you want via teamviewer

While running the IDE with the Arduino plugged in, this is the tasklist:

Image Name PID Session Name ========================= ======== ================ System Idle Process 0 Services System 4 Services smss.exe 284 Services csrss.exe 428 Services wininit.exe 512 Services csrss.exe 528 Console services.exe 560 Services lsass.exe 584 Services lsm.exe 592 Services winlogon.exe 668 Console svchost.exe 732 Services svchost.exe 808 Services MsMpEng.exe 924 Services svchost.exe 988 Services svchost.exe 112 Services svchost.exe 340 Services svchost.exe 420 Services DockLogin.exe 1040 Services svchost.exe 1148 Services spoolsv.exe 1372 Services svchost.exe 1400 Services armsvc.exe 1524 Services httpd.exe 1548 Services k9filter.exe 1604 Services UACProxy.exe 1632 Services svchost.exe 1664 Services httpd.exe 1988 Services LMS.exe 372 Services mysqld.exe 2528 Services NACAgent.exe 2564 Services SacNetAgent.exe 2688 Services SftService.exe 3040 Services sftvsa.exe 2028 Services taskhost.exe 3024 Console svchost.exe 3004 Services vmnat.exe 3116 Services WLIDSVC.EXE 3336 Services explorer.exe 3348 Console dwm.exe 3388 Console sftlist.exe 3564 Services WLIDSVCM.EXE 3644 Services vmware-authd.exe 3708 Services vmnetdhcp.exe 3764 Services vmware-usbarbitrator64.ex 3792 Services CVHSVC.EXE 3196 Services NisSrv.exe 3416 Services svchost.exe 4228 Services STService.exe 4460 Console Toaster.exe 4524 Console SynTPEnh.exe 4600 Console SynTPHelper.exe 1976 Console igfxtray.exe 4564 Console hkcmd.exe 4372 Console igfxpers.exe 4768 Console msseces.exe 4812 Console RAVCpl64.exe 3544 Console SacReminder.exe 4732 Console googledrivesync.exe 5084 Console SearchIndexer.exe 4876 Services StikyNot.exe 4312 Console RoxioBurnLauncher.exe 4304 Console WebcamDell2.exe 936 Console sprtcmd.exe 5132 Console jusched.exe 5168 Console AdobeARM.exe 5200 Console NACAgentUI.exe 5208 Console SSScheduler.exe 5652 Console DellDock.exe 5680 Console Dropbox.exe 5688 Console googledrivesync.exe 5780 Console sprtsvc.exe 3140 Services UNS.exe 4300 Services wmpnetwk.exe 4000 Services SeaPort.EXE 1324 Services wlanext.exe 2716 Services conhost.exe 8100 Services mscorsvw.exe 8164 Services chrome.exe 11856 Console chrome.exe 15980 Console wuauclt.exe 8040 Console chrome.exe 18924 Console chrome.exe 15484 Console chrome.exe 20308 Console taskhost.exe 18984 Console chrome.exe 20468 Console chrome.exe 15680 Console chrome.exe 17876 Console cmd.exe 16120 Console conhost.exe 2680 Console audiodg.exe 14988 Services WmiPrvSE.exe 20008 Services javaw.exe 17580 Console tasklist.exe 20020 Console

You have a lot of crap, I can't identify all, but you can start trying killing some process one by one. In a clean machine (just after boot) I think these are unneeded:

javaw.exe                    17580 Console
cmd.exe                      16120 Console
wmpnetwk.exe                  4000 Services
SeaPort.EXE                   1324 Services
RAVCpl64.exe                  3544 Console
SacReminder.exe               4732 Console
RoxioBurnLauncher.exe         4304 Console
WebcamDell2.exe                936 Console
sprtcmd.exe                   5132 Console
jusched.exe                   5168 Console
AdobeARM.exe                  5200 Console
NACAgentUI.exe                5208 Console
SSScheduler.exe               5652 Console
DellDock.exe                  5680 Console

Carthaginian: The OP and I are dealing with a similar problem, and we have at least one thing in common:

We originally used our boards with Linux. Everything worked fine then. Then we moved to Windows 7 (and I assume with the same boards) and started having problems.

At least in my situation, could Linux have messed with the ports? Any other ideas?

Ignore the message when windows tells you you have to reboot - i.e. say cancel

Then reenable the port and you will be good to go.

I suggest you go to the microsoft site and download sysinternal which can give you lots of info about hardware in use.

I would suggest you have turned on something in the IDE that is leaving a serial monitor (or some such) open each time you fire up the IDE

Craig

You're sure your arduino is on COM3? An easy way to make sure it is on COM3 is unplugging the board, looking at connected serial ports, and whatever has disappeared is the Arduino. If you're SURE that your arduino is on COM3, try using another USB port.

craigcurtin: Ignore the message when windows tells you you have to reboot - i.e. say cancel

Then reenable the port and you will be good to go.

I suggest you go to the microsoft site and download sysinternal which can give you lots of info about hardware in use.

I would suggest you have turned on something in the IDE that is leaving a serial monitor (or some such) open each time you fire up the IDE

Craig

To repeat what I said in the other thread:

Some good news. 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.