Source code for pynq.lib.pmod.pmod_grove_light

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from . import Grove_ADC


__author__ = "Yun Rock Qu"
__copyright__ = "Copyright 2016, Xilinx"
__email__ = "pynq_support@xilinx.com"


def _int2r(val):
    """Convert the integer value to the light sensor resistance.

    This method should only be used internally.

    Note
    ----
    A smaller returned value indicates a higher brightness. Resistance 
    value ranges from 5.0 (brightest) to 35.0 (darkest).

    Parameters
    ----------
    val : int
        The raw data read from grove ADC.

    Returns
    -------
    float
        The light sensor resistance indicating the light intensity.

    """
    if 0 < val <= 4095:
        r_sensor = (4095.0 - val) * 10 / val
    else:
        raise RuntimeError("Value out of range or device not connected.")
    return float("{0:.2f}".format(r_sensor))


[docs]class Grove_Light(Grove_ADC): """This class controls the grove light sensor. This class inherits from the grove ADC class. To use this module, grove ADC has to be used as a bridge. The light sensor incorporates a Light Dependent Resistor (LDR) GL5528. Hardware version: v1.1. Attributes ---------- microblaze : Pmod Microblaze processor instance used by this module. log_running : int The state of the log (0: stopped, 1: started). log_interval_ms : int Time in milliseconds between sampled reads. """ def __init__(self, mb_info, gr_pin): """Return a new instance of an Grove ADC object. Parameters ---------- mb_info : dict A dictionary storing Microblaze information, such as the IP name and the reset name. gr_pin: list A group of pins on pmod-grove adapter. """ super().__init__(mb_info, gr_pin)
[docs] def read(self): """Read the light sensor resistance in from the light sensor. This method overrides the definition in grove ADC. Returns ------- float The light reading in terms of the sensor resistance. """ val = super().read_raw() return _int2r(val)
[docs] def start_log(self): """Start recording the light sensor resistance in a log. This method will call the start_log_raw() in the parent class. Returns ------- None """ super().start_log_raw()
[docs] def get_log(self): """Return list of logged light sensor resistances. Returns ------- list List of valid light sensor resistances. """ r_log = super().get_log_raw() return [_int2r(i) for i in r_log]
[docs] def stop_log(self): """Stop recording light values in a log. This method will call the stop_log_raw() in the parent class. Returns ------- None """ super().stop_log_raw()