OK now we will verify that the driver installed properly.

Under Mac, in the Terminal window, type in ls /dev/cu.* which should give the following responses or so

The name we are looking for is /dev/cu.usbserial-XXXX where the X's are going to be unique for each cable. Copy and paste the name into a text file so you'll remember it for later.

For Linux/Unix type ls /dev/ttyUSB* into a terminal window, you should see a device file called something like ttyUSB0

If you are using Windows, go to the Device Manager (From the Start Menu, select Settings→Control Panel. Double click on System and select the Hardware tab. Then click on the Device Manager button)

Look for an entry under Ports (COM & LPT) that says USB Serial Port (COM) the COM number may vary but it should be something like COM3 or COM4 the COM number may be as high as COM99 so just look for the USB serial port. The COM stands for "communication", and each one has a unique number, known as the COM Port number. In this case the COM Port number is COM3. If you don't see the COM port verify the cable is plugged in, and check that you installed the VCP FTDI driver.

Then right click and select Properties

Click on the Port Settings tab, and click on Advanced…

Make sure Set RTS On Close used to be required for people using the Arduino IDE before like version 18 or so. Now you dont need it so make sure its not selected!