ORSSerialPort
Serial port library for Objective-C and Swift macOS apps
...You can use ORSSerialPort to write apps that connect to Arduino projects, robots, data acquisition devices, ham radios, and all kinds of other devices. Using ORSSerialPort to open a port and send data can be very simple. ORSSerialPort is released under an MIT license, meaning you're free to use it in both closed and open-source projects. However, even in a closed-source project, you must include a publicly-accessible copy of ORSSerialPort's copyright notice, which you can find in the LICENSE file. There are a number of ways to add ORSSerialPort to your project. ...