New "serial" port of the Uno and various programs

So HyperTerminal and Putty work fine with Win XP, but the com port for the Uno does not show up in Terra Term Pro.

I didn’t check if the windows inf file changed between 20 or 21 but I did re-install the “driver” after unzipping v21.

That makes me sad considering the teensy 2.0 works with TTP which is my preferred serial program.

Anyone else notice problems with other terminal programs or custom serial apps they have under Windows?

I am experiencing some problems with my Uno using the OneWire sample code [] on Linux ( Ubuntu Karmic and Lucid ) - the IDE becomes unstable and I cannot open the serial monitor and when I try I receive the following error message in the IDE: Serial port ‘/dev/ttyACM0’ not found. Did you select the right one from the Tools > Serial Port menu?..

I’ve previously tested with Blink and WebServer examples and everything worked as expected. Now the only way I can load new code is to attach the Uno to a Vista PC and overwrite the program.

I have tested the project hardware ( simple DS18S20 attached with pull-up resitor) with my Duemilanove and everything is working.

Has anyone else experienced any problems like this?

Well windows serial and linux serial are totally different beasts.

I’d suggest you start off having a shell window open on your linux host and do a “tail -f /var/log/syslog” before you start the IDE or connect your Uno. Then connect the uno to see what the OS says is going on, then start the IDE and select your board and serial port and then go through the remainder of steps to reproduce the problem. you should not see additional messages about the uno/usb tty disconnecting. If you do, take the syslog messages and post them here.

Thanks for the advice - this is what I did:

  1. “Reset” board by attaching to Vista PC and loading Blink - success!
  2. Open terminal on Linux PC
  3. Attach board to Linux PC - success - board is attached to ttyACM0 - syslog output:
    Oct 19 21:46:27 inspiron kernel: [ 3944.384022] usb 2-7: new full speed USB device using ohci_hcd and address 5
    Oct 19 21:46:27 inspiron kernel: [ 3944.599194] usb 2-7: configuration #1 chosen from 1 choice
    Oct 19 21:46:27 inspiron kernel: [ 3944.602408] cdc_acm 2-7:1.0: ttyACM0: USB ACM device
  4. Open IDE, set port to ttyACM0 and board type to Uno and reload Blink - success no errors
  5. Reload OnWire sample - you can see the port close
    Oct 19 21:49:01 inspiron kernel: [ 4098.029093] tty_port_close_start: tty->count = 1 port count = 0.

Now the IDE is locked and now I can no longer re-set the board.

Hmmm. Baud rate? Or try this commenting out everything in the loop, and then if that keeps the IDE from locking up, uncomment the first if statement in the loop to see if that’s the cause.

I will try to investigate the cause in more detail as suggested. Maybe there is a bug in the OneWire library that is only showing up on the Uno or there could be a problem with the USB implementation on the Uno or in the Linux driver.

If it is repeatable on other boards this does mean that in some projects this problem would stop you just dropping in the Uno as a replacement for the Duemilanove.

Serial port ‘/dev/ttyACM0’ not found

On Linux, did you happen to select 14400 or 28800 baud at any time? Even once, even for just a split second?

Linux doesn’t support these speeds and the RXTX library doesn’t support Linux not supporting them, so the result is RXTX loses all ability to talk to your port, as if it no longer exists. If you quit and restart Arduino, you’ll get a message about stale lockfiles, but then as soon as you try the serial monitor again, it remember the bad baud rate and the problem happens all over again. When I hit this, I had to edit the prefs file in the .arduino dir to “fix” it (back to a working baud rate).

Then again, you could have a completely unrelated problem. Just beware of those booby-trapped baud rates in Linux. They’ll ruin your whole day.