Where do serialport names come from?

Question

I'm currently writing a tool that automatically detects connected arduinos and provides a one-button solution for flashing new firmware. I've got a couple of arduinos at home (Diecimilla, Uno R3 SMD and some nanos from china) and each type presents with a different serial port name.

Questions

• Can someone explain where these port names come from?
• Can I assume that /dev/cu.usbserial-A9UPDRZB is, atleast in most cases, an arduino nano?
• Are there other ways to identify the type of the board?
• Is the name of the serial port some kind of hash generated from informations retrieved from the device?

Answer 1

You cannot assume anything about serial port names. It's a choice of the operating system, and even if you find the algorithm, there's no guarantee it won't change in the future.

As a reference implementation, the Arduino IDE 1.5.x uses VID (Vendor ID) and PID (Product ID) to identify a board.

Because accessing such information depends on the underlying operating system, the IDE uses three strategies: on windows, it runs a program called ListComPorts.exe, on macosx it uses CLI tool /usr/sbin/system_profiler, on linux CLI tool udevadm