Hacky way of displaying headset battery level by sniffing the raw bluetooth traffic and dumping it to a file

hspbatt.py

#! /usr/bin/env python3

import argparse
import pathlib
import pyshark


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("-o", "--output", type=lambda s: pathlib.Path(s).expanduser(), required=True)
    parser.add_argument("-i", "--interface", default="bluetooth0")
    args = parser.parse_args()

    # TODO: MAC address filtering
    shark = pyshark.LiveCapture(
        interface=args.interface,
        display_filter='bthsp.at_cmd == "+XEVENT" and bthsp.parameter == "BATTERY"'
    )

    for packet in shark.sniff_continuously():
        field = packet.bthsp.parameter.fields[1]
        # TODO: Maybe make this atomic?
        args.output.write_text(field.show)
        print("RX:", packet.bthsp.data)