I bought a cheap Arduino Nano clone from Aliexpress and when I tried to connect it to my mac (a MacBook Pro 13” 2013) it wouldn’t show up in the Arduino IDE as a selectable port for programming.

I read some pages about the problem and it seems that Mac OS since version Sierra has a problem with the driver for the USB-to-serial chip CH340G which the cheaper clones seems to use (you can see the chip in the photo below).

The solution that many people have come up with is to download and install a driver on your mac. This seems like a good idea until you get into the details. A part of the solution to get the driver to work is to turn of the Mac OS kernel extension signing check, like so:

sudo nvram boot-args="kext-dev-mode=1"

I think it’s a bit risky to download unknown and unsigned software from the web, install it as a kernel extension and turn of the signing check for your entire system. Go ahead and use that solution if you want an easy way out and don’t care about your system integrity. I will go the hard way and use a separate USB-to-serial component instead.

Using a YP-05 USB to serial FTDI chip

There seem to be another chip manufacture called FTDI which has better mac compatibility with its USB chips. So I will use one of its USB-to-serial converter to program my Arduino Nano.

Connect the wires from the USB chip to your Arduino according like this:

  • GND to GND
  • VCC to Vin
  • RX to TX1
  • TX to RX0

Now you can use your Arduino IDE to program your Nano. There is however no reset connection between the USB chip and the Nano so you have to manually press the RESET button on your Nano just before the upload will start from your Arduino IDE.