Thanks, that was very helpful. I was focused on the wrong problem to solve, at least for now.
So I’ve finally been able to get Processing to pull the system time from the Mac (Hooray!), but I can’t prove that it’s getting to the Arduino because I can’t seem to run Arduino, processing, and the Arduino serial monitor at the same time. For some reason, I think the Arduino, processing , and the Arduino serial monitor are all competing for tty.usbmodemfa141, instead of sharing it. How do I get them to all use 141 without conflicting?
Sometimes I get the message in processing "error inside serial.0".
To solve this, sometimes I can reload the Arduino and reload processing, in that order. When this works, then I do see the correct time in the monitor window at the bottom of the processing window, but I can’t get the Arduino serial monitor to open up to prove the data is getting to the Arduino, and I get this message:
“Serial port ‘/dev/tty.usbmodemfa141’ already in use. Try quitting any programs that may be using it.”
For some reason, I think the Arduino, processing , and the serial monitor are all competing for tty.usbmodemfa141, instead of sharing it.
Can you suggest a next step or point me to an appropriate resource? Thanks again for all your help - Bryan