Driver -NanoESP & Pretzelboard
The Pretzelboard (NanoESP) needs a driver for the USB-to-Serial Chip CH340G to work properly. You can download the driver here:
Mac Version (Attention: There seems to be a problem with MAC OS Sierra. Bellow are two links with walkthroughs:
There is a Setup.exe file (Windows Version) in the Zip-Folder which needs to be executed. Choose Install in the following Window.
After a short time a message confirm the successful installation. Now you can plug in your Board und the driver will be chosen automatically.