Arduino resets UNO board on Serial Monitoring- rxtxSerial.dll

I just noticed the Arduino 1.0 causes my UNO board to reset each time I open the serial monitor window.
Maybe is something related with my system configuration since in the past I had some issues with Arduino menu caused by the available serial ports. In that case the menu was extremely slow and I found that the solution was to replace the rxtxSerial.dll with a different one provided on old forums (unfortunately I don't have the link to that post)
So following the same method I just replaced the rxtxSerial.dll with the old one and the problem is solved.

If someone experiencing the same problem the file is available for download here: File Dropper - Online file sharing

Thanks

The board reset is somewhat by design (I thought the UNO might have a jumper to defeat the reset if desired). Generally a 100 ohm resisitor placed between the +5v pin and the reset pin blocks the board reset when desired. With your fix, you may encounter issues uploading programs.

Just to clarify my previous post:

  • The board working like a charm with previous versions of Arduino IDE.
  • The issue appeared on Arduino 1.0 (and probably my system configuration is a part of the issue).
  • I'm not facing any problem on upload (either with original rxtxSerial.dll, either with the altered one).
  • The auto reset is still functioning on upload without any problem.
  • The only issue was the auto reset caused by Arduino IDE when monitoring window. This is not a function as far I can tell. Its a real pain if you want to check the status on a running device.
  • The auto reset was never caused by third party serial monitoring software.

The only issue was the auto reset caused by Arduino IDE when monitoring window. This is not a function as far I can tell. Its a real pain if you want to check the status on a running device.

I'm not sure what "monitoring window" is, but the IDE does reset the arduino when another IDE window is opened. I learned about that when I had an email test program loaded on the arduino and was opening other IDE windows working on some code. Every time I opened another IDE window, the board reset and sent a new email.

zoomkat:

The only issue was the auto reset caused by Arduino IDE when monitoring window. This is not a function as far I can tell. Its a real pain if you want to check the status on a running device.

I'm not sure what "monitoring window" is, but the IDE does reset the arduino when another IDE window is opened. I learned about that when I had an email test program loaded on the arduino and was opening other IDE windows working on some code. Every time I opened another IDE window, the board reset and sent a new email.

I believe that behavior is cause by the need for the newly launched IDE to have to scan for all avalible serial ports so it can populate it's serial port selection drop down menu.

Lefty

What happens is that under the hood, RXTX scans the ports, and at one point attempts to open and read the port (checking permissions).

If on *nix / BSD you have your initial settings to enable RTS/CTS and DTR/DTS it will reset the Arduino on port open.

On FreeBSD you can issue the following command:
stty -f /dev/tty??.init -crtscts -hupcl -ixon -ixoff -ixany

Hope this is of help?