How to retrieve USB-to-serial address?

Question

ISSUE

Pyserial: A USB serial device has different addresses depending on whether I install it to a desktop (Catalina) or laptop (High Sierra):

ser = serial.Serial('/dev/cu.usbserial', 9600) #OSX High-Sierra
ser = serial.Serial('/dev/cu.usbserial-1D120', 9600) #OSX Catalina

Is there a method to use a wildcard? /dev/su.usbseria*. The goal is one line of code that will handle either case.

Any insight as to why -1D120 was appended, is appreciated.

REFERENCES

Example

import serial.tools.list_ports
#Find USB Port
def find_port():  #Finds which port the arduino is plugged into
    ports = list(serial.tools.list_ports.comports())
    for p in ports:
        if '0403' in p[2]: #unique to Osepp Uno (arduino clone)                
            return p[0]

Assume that the target string (regular expression) is of the format:

/dev/cu.usbserial**************

How would the above snippet of code be modified to trap and return the USB serial device?

Iterate over available ports (see [this answer](https://stackoverflow.com/a/54584801/581190)) and choose the one you'd like to use. — zrzka, Aug 17 '20 at 07:09

score 0 · Answer 1 · answered Mar 23 '21 at 22:41

Note: This answer was cut from the question and properly posted here.

Retrieve USB-to-serial address and open port

YMMV: mind the algorithm limitations. Especially the trapping string: if there is more than one instance found (trapped), the last trapped list item will be returned => it may or may not be the intended target string.

import serial.tools.list_ports    
ports = list(serial.tools.list_ports.comports())
for p in ports: 
    #print(p[0])  #p[0] => target string
    if 'usbserial' in p[0]: #OSX: Trap usbserial device  /dev/cu.usbserial-1D120              
        serAddr=p[0]
    if 'ttyUSB' in p[0]: #Ubuntu :Trap usbserial device  /dev/ttyUSB0
        serAddr=p[0]              

ser = serial.Serial(serAddr, 9600) # Open port at 9600 baud

A third untested trap for checking windows COM ports can be added:

import serial.tools.list_ports    
ports = list(serial.tools.list_ports.comports())
for p in ports: 
    #print(p[0])  #p[0] => target string
    if 'usbserial' in p[0]: #OSX: Trap usbserial device  /dev/cu.usbserial-1D120              
        serAddr=p[0]
    if 'ttyUSB' in p[0]: #Ubuntu :Trap usbserial device  /dev/ttyUSB0
        serAddr=p[0]              
    if 'COM' in p[0]: #Windows :Trap usbserial device  COM3 COM7 etc.
        serAddr=p[0]

How to retrieve USB-to-serial address?

ISSUE

REFERENCES

1 Answers1