# -*- coding: utf-8 -*-
"""Capture UART to a file for N seconds (OTA/BLE debug sessions)."""
import sys
import time

import serial

port = sys.argv[1] if len(sys.argv) > 1 else r"\\.\COM4"
out = sys.argv[2]
dur = float(sys.argv[3]) if len(sys.argv) > 3 else 120

ser = serial.Serial(port, 115200, timeout=0.2)
t0 = time.time()
with open(out, "wb") as f:
    while time.time() - t0 < dur:
        data = ser.read(4096)
        if data:
            f.write(data)
            f.flush()
print("captured to", out)