Digital output, analog input.
For this assignment I took an existing thing I made for week 1 of fabrication, which was a light fixture device I wanted to use to study colours next to each other. Basically two pots controlled the brightness of the neopixels on each side of the steel beam. One side is blue, one side is orange. (When I have more time I will code them to change hue in addition to just brightness.)
however, after that first week, I basically did something wrong to the Nano that was powering it when I tried to put more power into the neopixels. I had previously been running it on very low power (like 10 of 255) so as to not tax the power supply or nano. But something happened and the nano stopped working. Perhaps it was because I wired the 12V power supply directly into the nano and supplied the neopixels with power directly and only from the arduino.
So I rewired it to a new arduino, and since i think the last error had something to do with using the 12V power supply overloading the nano (my hypothesis) I thought I would run it through a LM7805 power regulator. That is, the power supply would power the neopixels exclusively through the power regulator instead of getting it from the 5V arduino output.
The end result is that the whole thing works when I power the arduino through the USB, but does not work properly when I do it through the 12V 1A wall wart power supply. I’m not sure why….