I have been able to confirm that my Arduino Uno is in DFU mode. By checking in "About this mac", "System Report", and "USB" I have been able to see the my Arduino recognized in two states, depending on whether or not the pins have been shorted. (when I short the pins it is no longer recognized as an Arduino, but a different device from "atmega corp") This means the chip is in DFU programming mode and can have its firmware updated.
I am still having trouble with dfu-programmer though. The dfu-programmer menu prints out, but when trying to erase the firmware on the Arduino I still get the error no device present
I have found a thread where somebody seems to have had the exact same problem I am having, and was able to solve it, but they did not post exactly how they did it. They just said that they weren't actually running things as a root user and were able to and that solved it for them.
The thread is here: Arduino Forum
If anybody can make more sense of it than I can I would really appreciate some insights. I am very discouraged at this point. All libraries seem to have been installed, the chip is clearly in DFU mode, so I really don't know what else to do, except to uninstall and reinstall all of the tools I have downloaded..
Edit: upon further investigation, I am relatively sure that my issue is that I am running the unpatched version of dfu-programmer from within the terminal, even though there is a patched version on my machine. Can anybody help me figure out how I would use the patched one over the unpatched one? Or is this issue even possible? There are like 10 different versions of dfu-programmer on my machine right now.
Thanks for any help