def huba505(voltage):
    """
    Given that v is voltage in Volts, return pressure as given by a HUBA 505 transducer

    The transducer is:
    0.5V    -   0 bar
    3.5V    -   4 bar
    """
    pressure = 4 * (voltage - 0.5) / 3
    if pressure > 0:
        return pressure
    else:
        return 0