The Arduino Nano is a fantastic little device that can do a wide variety of things. It is also, like it’s bigger sisters, a target for cheap clones which perform similar range of functions with cheaper parts. While I’m not opposed to this, per se, especially in the education and prototyping spheres, the lack of documentation on these devices can make the initial experience somewhat frustrating. When I first began working with Arduino, I couldn’t–for the life of me–find out how to install the correct Arduino Nano driver for my Mac. The genuine Arduino uses the FTDI USB-to-serial chip which is fairly easy to source and comes with sufficient documentation, but the microcontrollers I bought off eBay use a different chipset to handle the data conversion.
To install the correct Arduino Nano driver, one must first locate the USB-serial conversion chip. This will be located on the bottom of the device, close to the USB port itself.
The chip will have its designation printed on it. A little white-belt Google Fu will get you to the correct drivers. In this case, it was not the FTDI chip, but the CH340 handling the conversion. This generally works for Windows and even Linux machines, but to compound the issue of using a CH34x chip with a Mac is that there really isn’t an “official” driver for the OS. On Mac, you’re really going to need MPParsley’s driver from GitHub as the drivers from the manufacturer will actually cause a kernel panic on MacOS (you know, Sierra/10.12+). It’s a fairly simple matter of downloading the package file, installing the package, then rebooting.
If, for some reason, you managed to install the wrong drivers on your Mac, the GitHub article also has instructions on how to remove the broken driver. It’s a pretty simple matter of using Terminal to remove the offending entries in the Library folders, much like one would do on a Linux machine.