yet another serial port com7 already in use

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slsmet
 
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yet another serial port com7 already in use

Post by slsmet »

I'm stumped getting my brand new Arduino Uno up and running.

Windows XP 2003, service pack 3
Dell Lattitude E6400 laptop

I've got the IDE downloaded, unzipped, installed. USB cable connected to the PC and Arduino.

When I try to upload a sketch to the Arduino, I get the message "serial port "com 7" already in use…"

I'm using the Examples/Basics/Blink sketch.

The on-board power "on" light glows green cheerfully. The pin 13 led blinks orange at about 1 Hz. Tx and Rx do nothing during the upload attempt.

The sketch window itself shows "Uno R3 on com7" in the lower right corner.
Tools/Board shows "Uno"
Tools/Serial Port shows "com7" as checked (chosen)
"ArduinoUnoR3 on com7" is shown in the device manager

Things I've tried:
1. Restarting the PC (with and without the Arduino connected at start-up)
2. Disconnecting/reconnecting the USB cable
3. Disabling and enabling com7 with the device manager
4. Reinstalling the driver
5. Uninstalling the device
6. Pressing the Arduino reset button at various intervals during the upload attempt
7. Using a different physical USB port
8. Turning off laptop Bluetooth and WiFi communications
9. Closing every program except Arduino IDE
10. Uninstalling and deleting, then re-downloading the Arduino software from Arduino.com
11. Verified the USB cable works for other devices and printers
12. Other sketches in the examples folder
13. As many sequential combinations of the above as I can think of

What am I missing?

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adafruit_support_bill
 
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Joined: Sat Feb 07, 2009 10:11 am

Re: yet another serial port com7 already in use

Post by adafruit_support_bill »

There are a couple causes for this that I know of.

The most common one in my experience is that the Java runtime (upon which the Arduino IDE is built) fails to close the COM port. This can usually be cured by shutting down all Java-based apps on the machine. This affects some browser plug-ins also, so sometimes it is simpler just to re-boot the machine.

The other cause I see occasionally are machine services that 'reserve' blocks of COM ports. Bluetooth stacks are notorious for this. Some of these services will allow you to configure the range of reserved ports.

When you plug in your Arduino, do you see it show up in the Device Manager? You might try re-assigning it to a different port.

slsmet
 
Posts: 5
Joined: Thu Dec 31, 2009 9:24 am

Re: yet another serial port com7 already in use

Post by slsmet »

Thank you,

When I connect the Arduino, it indeed shows up in the Device Manager on com7. That matches the com7 shown in the Tools/Serial Port pull-down in the IDE and it matches the com7 shown in the bottom right corner of any sketch, when the board is connected.

When I disconnect the Arduino, it disappears from the device Manager and I'm only left with two com ports listed, both of which are assigned to other things:
Bluetooth Communication Port (com4)
Intel Active Management Technology (com3)

I'm not sure how to assign the Arduino another com port. Can you explain?

Regarding Java, I have re-booted the PC many times and have started ONLY the IDE, no other programs, browser or apps. Might there be something running in the background that I don't manually start that is using Java and causing the problem?

I appreciate your help.

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adafruit_support_bill
 
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Joined: Sat Feb 07, 2009 10:11 am

Re: yet another serial port com7 already in use

Post by adafruit_support_bill »

I'm not sure how to assign the Arduino another com port. Can you explain?
If I remember correctly, on XP you can change the assigned com port by opening "properties" on the device in Device Manager and going to the "advanced" tab.
When I disconnect the Arduino, it disappears from the device Manager and I'm only left with two com ports listed, both of which are assigned to other things:
Bluetooth Communication Port (com4)
Intel Active Management Technology (com3)
On one of my old XP machines, I had to disable bluetooth entirely to get it to work. Not sure what "Active Mangement Technology" is, but it sounds scary :wink: .
Regarding Java, I have re-booted the PC many times and have started ONLY the IDE, no other programs, browser or apps. Might there be something running in the background that I don't manually start that is using Java and causing the problem?
From what I can figure out, the Java runtime loads whenever any Java based app runs and stays loaded as long as any of them are still active. All system resources are managed through that runtime and if one app doesn't clean up after itself, nothing gets released until you kill the runtime. You may not be explicitly loading any java apps, but if your machine is like most, there are a bunch of services and toolbar widgets that get launched at startup, and some of them may be Java based.

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kscharf
 
Posts: 277
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Re: yet another serial port com7 already in use

Post by kscharf »

Don't forget that the Arduino IDE itself uses Java!

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