Problems with COM port on Ubuntu.

Everything was fine until arduino IDE suddenly closed my COM port and sent me a message about error when opening COM port.

    processing.app.SerialException: Error when opening serial port '/dev/ttyUSB0'.
	at processing.app.Serial.<init>(Serial.java:178)
	at processing.app.Serial.<init>(Serial.java:77)
	at processing.app.debug.Uploader.flushSerialBuffer(Uploader.java:77)
	at processing.app.debug.AvrdudeUploader.uploadViaBootloader(AvrdudeUploader.java:175)
	at processing.app.debug.AvrdudeUploader.uploadUsingPreferences(AvrdudeUploader.java:67)
	at processing.app.Sketch.upload(Sketch.java:1671)
	at processing.app.Sketch.exportApplet(Sketch.java:1627)
	at processing.app.Sketch.exportApplet(Sketch.java:1599)
	at processing.app.Editor$DefaultExportHandler.run(Editor.java:2380)
	at java.lang.Thread.run(Thread.java:745)
    Caused by: gnu.io.UnsupportedCommOperationException: Invalid Parameter
	at gnu.io.RXTXPort.setSerialPortParams(RXTXPort.java:213)
	at processing.app.Serial.<init>(Serial.java:163)
	... 9 more
    processing.app.debug.RunnerException: Error when opening serial port '/dev/ttyUSB0'.
	at processing.app.debug.Uploader.flushSerialBuffer(Uploader.java:101)
	at processing.app.debug.AvrdudeUploader.uploadViaBootloader(AvrdudeUploader.java:175)
	at processing.app.debug.AvrdudeUploader.uploadUsingPreferences(AvrdudeUploader.java:67)
	at processing.app.Sketch.upload(Sketch.java:1671)
	at processing.app.Sketch.exportApplet(Sketch.java:1627)
	at processing.app.Sketch.exportApplet(Sketch.java:1599)
	at processing.app.Editor$DefaultExportHandler.run(Editor.java:2380)
	at java.lang.Thread.run(Thread.java:745)

I reinstalled arduino IDE and tried again but it still didn’t open. Then I tried to replace controller and it also didn’t help. So I decided that there had been problem with arduino board. But today I suddenly have found out that on Windows it works fine. Unfortunatly I have no other virtual COM devices to check their work. What could be the problem?

Hi, welcome to the forum.

Which linux version and which Arduino version and which Arduino board do you use ?

It might be a conflict with older versions and the Java RX TX library.

Please remove all Arduino packages from the repositories. They are old and outdated.
Remove the Java RX TX library. I think the package name is "librxtx-java".
I did install the "default-jre" and "java-common" and a number of Java packages that came along with those. But no more Java.

Download Arduino IDE 1.6.1 and unpack it in a folder. Run it from that folder.

It could still be some hardware problem... ::slight_smile:

  1. Which version of the IDE are you using?
  2. open a terminal and type “groups” and paste the output on the forum