Microbit serial to file script

How do you save thousands of lines from the micro:bit connected via the serial port to a file?

screen? Cut and paste from the terminal?

That gets tiring after a while. Furthermore, the name of the serial device on OS X keeps changing.

Well, here's a handy little script. It looks for the first connected micro:bit and then copies the serial output to stdout. You can tee or pipe it to a file.

Requires pyserial. Only tested on OS X. As usual, use at your own risk.

import serial
from serial.tools.list_ports import comports as list_serial_ports
import sys

def get_microbit_port(ser_id):
    ports = list_serial_ports()
    if ser_id != "": 
        for port in ports:
            if ser_id in port[2]:
                return port[0]
        return None
    for port in ports:
        if "VID:PID=0D28:0204" in port[2]:
            return port[0]
    return None

def main():
    id = ""
    if len(sys.argv) > 1:
        id = sys.argv[1]
    port = get_microbit_port(id)
    if port == None:
        print("micro:bit not connected")
        sys.exit(1)

    try:
        ser = serial.Serial(port, baudrate=115200)
        while True:
            line = ser.readline()
            print line,
            sys.stdout.flush()
    except serial.SerialException as e:
        print "Serial line disconnected"
    except KeyboardInterrupt:
        print "Quit"
    finally:
        try:
            ser.close()
        except:
            pass

main()