WMR-100 Wetterstation beispiel

"""
WMR-100 Wetterstation
=====================

Not everything is included.
Some devices/features are missing
and it's not tested
"""


import binascii
import struct
from collections import namedtuple


FRAMES = {
    0x30: "handle_datetime",
    0x46: "handle_pressure",
    0x42: "handle_temperature",
    0x48: "handle_wind",
}


Datetime = namedtuple("DateTime", "frame datetime checksum")
Pressure = namedtuple("Pressure", "frame prediction pressure checksum")
Temperature = namedtuple("Temperature", "frame sensor_id temperature humidity power_supply checksum")
Wind = namedtuple("Wind", "frame direction speed_mps speed_mph checksum")


def handle_datetime(data):
    result = struct.unpack("<b3x5bxb", data)
    frame, minute, hour, day, month, year, checksum = result
    return Datetime(frame, datetime.datetime(2000 + year, month, day, hour, minute), checksum)


def handle_pressure(data):
    if data[0] != 0x46:
        raise TypeError("Wrong frame")
    frame, prediction, low_pressure, high_pressure_nibble, checksum =  struct.unpack("<bx4b", data)
    weather = ["Partly Cloudy", "Rainy", "Cloudy", "Sunny", "Snowy"]
    prediction >>= 4
    try:
        prediction = weather[prediction]
    except IndexError:
        raise TypeError("Unknown prediction")
    high_pressure_nibble &= 0x0f
    pressure = high_pressure_nibble << 8 | low_pressure
    return Pressure(frame, prediction, pressure)


def handle_temperature(data):
    if data[0] != 0x42:
        raise TypeError("Wrong frame")
    frame, sensor_id, temp, humidity, power_supply, checksum = struct.unpack("<2bh2b3xb", data)
    sensor_id &= 0x0F
    temp /= 10
    psu = {0x50: "no AC", 0x6E: "AC OK"}
    return Temperature(frame, sensor_id, temp, humidity, psu.get(power_supply, "Unkown Power Supply"), checksum)


def handle_wind(data):
    if data[0] != 0x48:
        raise TypeError("Wrong frame")
    frame, direction, speed, checksum = struct.unpack("<2bxb4xb", data)
    direction &= 0x0F
    directions = "N E S W".split()
    return Wind(frame, directions[direction], speed * 0.1, speed * 0.36, checksum)


def handle_hexstr(text):
    data = binascii.unhexlify(text.replace(" ",""))
    try:
        func_name = FRAMES[data[0]]
        func = globals()[func_name]
    except KeyError as e:
        raise TypeError("Frame Type is not known") from e
    return func.__name__, func(data)



def main_loop():
    """
    Testfunktion
    """
    time_stamp = None
    temperature = None
    pressure = None
    wind = None

    while True:
        hex_str = input("Bitte Hex Sting eingeben: ")
        func_name, result = handle_hexstr(hex_str)
        if isinstance(result, Datetime):
            time_stamp = result.datetime
        elif isinstance(result, Temperature):
            temperature = result.temperature
        elif isinstance(result, Pressure):
            pressure = result.pressure
        elif isinstance(result, Wind):
            wind = result.speed_mph
        print(time_stamp, temperature, pressure, wind)