how to avoid reset when starting serial monitor?

Is there a way to avoid having my sketch reset when I start the serial monitor? I'm using a Diecimila with arduino-0010 under MacOS X 10.5. I can see why the reset might be useful for some people, but I want to have a long-running sketch going on the board that I can check in on from time to time.

Did you read this?

And there's a non-temporarily hardware solution (to remove the cap labeled as R3 on schematics), but I don't recommend it, except if you soldering skill are good.

Did you read this?

No, I didn't have any luck searching for previous discussions - thanks very much for the link! The HUPCL trick sounds like it would do the trick for me, assuming I can ferret out what the necessary C incantations are...

For what it's worth, I'm building a simple event & temperature logger that sits around and collects data on an EEPROM. Periodically, I want to make a serial connection to it to check the current state of the sensors, download the data, clear the data store -stuff like that. It would be awkward to have it reset every time I made a serial connection. (It's awkard now, having to leave it plugged into my laptop while it runs...)

If you discover how to do it with software, tell us.

Since I couldn't do it through software, I implemented a hardware solution on Arduino S3v3 Beta, that's only a jumper that disables auto reset for cases like your. Just remove the jumper, and Arduino will not reset automatically. If the software solution doesn't exist, or if it get too complicated, at least a hardware simple solution already exists, and it is being tested sucessfully. Perhaps this could became a standard for newer Arduinos...

I'm actually interested in doing the exact same thing (occasional serial connections to Boarduino to change which LED is lit) My setup is:

  • Perl using Win32::SerialPort
  • Windows XP
  • Boarduino with what i suspect is the NG firmware due to a 7 second sketch start delay.

I've read on misc threads about shortcutting the reset:

And general perl serial interfacing:

.. And I know the Boarduino gives you the option to simply not solder the cap that will tie the reset to the serial but I would prefer to keep that auto reset if I can get away with it via the HUPCL feature I was seeing in some of the linux threads. I suspect that i should be able to do the same thing with the Windows Com Port setup (Set RTS on Close?)

The project I'm looking to create is basically a street light with LED's that will show the current state of my network / monitored infrastructure. A scheduled task will run occasionally and go and retrieve the state of a monitor, that monitor will return something like, "Normal, Warning, Danger" or whatever to the program. Based on that I want to turn around, open a serial connection on the Boarduino, and change the color of the LED to the appropriate green, yellow, red, and then disconnect since this will most likely be running off of a laptop, which might at anytime be undocked, and I would like the board to simply keep it's last known state. I saw another project that did it with the OneWire: but I would like to do the same thing with the Arduino technology. Any help or tips would greatly appreciated.