Ok, newbie here. Just got my first Arduino
Using a VCP connecting via a USB port.
Virtual Com Port - check
Loading programs and running - check.
The problem?
I just loaded a program to send data to my computer with the Serial.println commands. The loaded program runs constantly, no end to the serial port use. Now, every time I try to burn a new program, Arduino programmer tells me my com port is already in use. Grrr.. the only program using the com port is the running program on my Arduine Duemilanove.
Any ideas on how to get arount this little pickle?
When a program on the host computer complains that "com port is already in use", it is not referring to the fact that the Arduino program is sending data on the Arduino port. It thinks that there is another (host computer) program running that has opened the serial port on the host. (Conceptually, there are two serial ports: one on the Arduino and one on the host. They happen to be connected in this case.)
Bottom line: look for some other program on your computer that is grabbing the port.
He's got both programs in front of him. One is the Arduino environment, and the other is his serial comm program.
I'm afraid that that's pretty much the way things are; things that use the comm ports pretty much want "exclusive access", for relatively obvious reasons. I usually put a "delay(5000)" or similar in setup for me to re-start the serial comm program if I'm going to be using one other than the one built into the arduino environment. In the long term, of course, I won't be re-programming the Arduino...
Thank you both for your replies.
I did have hyperterminal open to capture the serial data for a while. Even after exiting - it took a computer reboot, and a little trying before I could re-program the Arduino. Still not sure what combination worked, but I am glad it did!
My lesson - allow some option for the serial communications to end gracefully. Since I was just tinkering with a way to get data logging on my computer, I really didn't need to keep it sending data perpetually!
One thing that works for me when having both a standalone terminal program opened and the Arduino IDE open is to select a different comm port for the program that is not needed for the moment. That appears to release the port.
One terminal program I use a lot is the Brey terminal and it has a command button to disconnect from a comm port so it's easy to deactivate without having to close it out.
