I am a newbie trying Duemilanove on Mac Pro [dual Nehalem Quad Core running OS X 10.5.6]. I communicate with the Drumilanove via its onboard USB port. I of course installed the appropriate FTDI USB Serial Driver for the Intel Mac.
I use Tod Kurt's Arduino serial communication script from the "instructables" website [I can't give the URL here as this is my first post, but it starts with the usual w w w followed by the word above in quotes followed by dot-com and then /id/ST70QVYFS6PHWCB/] to communicate with the Duemilanove from the Mac, both from within AppleScripts and also from the command line of an X terminal session.
I have no problem uploading sketches such as the standard Arduino PhysicalPixel example to the Duemilanove.
But unless I have the Arduino Environment running and its Serial Monitor enabled, my "H" and "L" characters sent by typing for example "~/Documents/arduino-serial -b 9600 -p /dev/tty.usbserial-A6008cKX -s L" [without the quotes] into a terminal screen don't work.
If I have the Arduino-0015 environement running and the Serial Monitor enabled, all is fine.
This seems awkward, and its hard to believe it is 'normal' behavior. I am suspecting some sort of timing issue, and suspect that running the serial monitor slows things down just enough so that things work. But I could be all wrong.
Any suggestions about where to look for a solution or explanation?
I looked thru the forums here using search and also just browsing, and Googled for a few hours with no luck.
Thanks in advance!