Vertical rate from barometric measurement, this value may be very noisy.

    Args:
        msg (String): 28 bytes hexadecimal message (BDS60) string

    Returns:
        int: vertical rate in feet/minutes

def vr60baro(msg):
    """Vertical rate from barometric measurement, this value may be very noisy.

    Args:
        msg (String): 28 bytes hexadecimal message (BDS60) string

    Returns:
        int: vertical rate in feet/minutes
    """
    d = hex2bin(data(msg))

    if d[34] == '0':
        return None

    sign = int(d[35])    # 1 -> negative value, two's complement
    value = bin2int(d[36:45])

    if value == 0 or value == 511:  # all zeros or all ones
        return 0

    value = value - 512 if sign else value

    roc = value * 32   # feet/min
    return roc