Serial Communication Tool For OSX

Coming from a Windows background I previously used HyperTerminal as a serial communication tool. When I moved to a Mac I tried an app called zterm that is a sort of HyperTerminal equivalent, but found it to be a bit cumbersome. The best, and my favourite way that I have found to accomplish communication over the serial port in OSX, is with a Terminal app called screen.

Don't fear the command line!

To use it you first need to open Terminal via Applications->Utilities->Terminal. Then you need to get a list of the serial ports available. These devices are listed in the /dev folder and all start with the prefix tty. To see a list of all the serial ports on your computer, type:

ls /dev/tty.*

The ls is the Unix list command and the * after tty. is a wild card so that you are returned a list of everything in the /dev folder that starts with tty., namely all your serial ports. To connect to one of those serial ports you need to use screen. The format for calling screen is:

screen portname datarate

For example, to connect to a serial port called /dev/tty.usbserial-A3000Xg3 at 9600 bits per second, type:

screen /dev/tty.usbserial-A3000Xg3 9600

Now anything you type will be sent out the serial port (though there is no local echo of your typing) and anything the serial port receives will be displayed on the screen. The command to close the serial port is Control-A followed by Control-\.

For more info on screen check the man pages by typing:

man screen