Source code for caspia.node.components.sensors.datatypes

import struct


def parse_co2(data):
    """Return float on valid co2.

    None, on measurement error (INVALID_VALUE).
    """
    if len(data) != 2:
        raise ValueError
    if data == b'\xFF\xFF':
        return None
    co2, = struct.unpack('<H', data)
    return float(co2)


def parse_temperature(data):
    """Return float on valid temperature.

    None, on measurement error (INVALID_VALUE).
    """
    if len(data) != 2:
        raise ValueError
    if data == b'\xFF\xFF':
        return None
    temp, = struct.unpack('<h', data)
    return temp / 100


def parse_analog_uint10(data):
    """Return float in range 0-1 if data are valid.

    None if value is invalid. Raises value error if data are invalid.
    """
    if len(data) != 2:
        raise ValueError
    if data == b'\xFF\xFF':
        return None
    value, = struct.unpack('<H', data)
    return value / 0x3FF


def parse_humidity(data):
    if len(data) != 2:
        raise ValueError
    if data == b'\xFF\xFF':
        return None
    value, = struct.unpack('<H', data)
    return value / 100