Testing Serial Read - MacOS

I’ve got a working sketch on my Uno which is designed to be used with some slot car race control software I run on an old PC.

The sketch monitors the serial port for messages from the race control software and illuminates some adafruit neopixel (RGB LEDs) depending on the data it receives.

What I’d like to be able to do is create a dummy programme on my mac which sends test messages to the serial port (uno) - so I can test a few ideas I have.

I’m just wondering if anyone can suggest a way to do this?

This Python - Arduino demo may help get you started.

Serial Input Basics

thanks for your reply - will take a look at that.