I decided to upgrade the household iMac to 10.11.3 (from 10.8, I think), but not because 10.11 offered any valuable new features. In fact, just the opposite—a student in my freshman design seminar was having trouble getting PteroDAQ to work on 10.11.3, and I need to debug the problem.
It took well over an hour to download the upgrade—6.9Gbytes! All the text in Wikipedia could be transmitted in about 9GBytes. What junk is Apple loading my computer with? Sometimes I long for the days when the operating system fit on a 700kB floppy disk.
After downloading, it supposedly takes about half an hour to install (I’m still waiting for that to finish). [Update: after over half an hour, I went to check on it, and it now claims 45 minutes remaining.] I don’t know how much fussing I’ll need to do to get the new OS working—there always seems to be something broken on each new upgrade of the system. All that time, before I can even look at what they broke/changed in OS 10.11 to make PteroDAQ not work.
Because the Arduino software was able to download to the board, but PteroDAQ was not then able to see the board, I suspect that port listing method has changed, and PteroDAQ code will need to be updated to do something different in OS 10.11 than in the earlier Mac OS versions (there is already very different code for Mac, Linux, and Windows, which share almost nothing in how to list the USB ports—we may need two different Mac code versions).
I was able to solve one student’s problems with the Arduino system losing track of ports, by suggesting he update from 10.11 to 10.11.3. It seems like the 10.11 release had a new USB stack, which Apple’s was beta-testing on live customers rather than spending the time to do their own QA. (This didn’t use to be such a problem with Mac releases, but has always been a problem with iOS releases—it seems that bad software engineering practice is driving out good at Apple.) I checked, and the student having trouble with PteroDAQ did have 10.11.3, so the problem is not so easily resolved as the Arduino problem was.