Source code for platypush.plugins.gpio.sensor.motion.pwm3901

import enum
import math
import time

from platypush.plugins import action
from platypush.plugins.gpio.sensor import GpioSensorPlugin


[docs]class Rotation(enum.IntEnum): ROTATE_0 = 0 ROTATE_90 = 90 ROTATE_180 = 180 ROTATE_270 = 270
[docs]class SPISlot(enum.Enum): FRONT = 'front' BACK = 'back'
[docs]class GpioSensorMotionPwm3901Plugin(GpioSensorPlugin): """ Plugin to interact with an `PWM3901 <https://github.com/pimoroni/pmw3901-python>`_ optical flow and motion sensor Requires: * ``pwm3901`` (``pip install pwm3901``) """
[docs] def __init__(self, rotation=Rotation.ROTATE_0.value, spi_slot=SPISlot.FRONT.value, spi_port=0, **kwargs): """ :param rotation: Rotation angle for the captured optical flow. Possible options: 0, 90, 180, 270 (default: 0) :type rotation: int :param spi_slot: SPI slot where the sensor is connected if you're using a Breakout Garden interface. Possible options: 'front', 'back' (default: 'front') :type spi_slot: str :param spi_port: SPI port (default: 0) :type spi_slot: int """ from pmw3901 import BG_CS_FRONT_BCM, BG_CS_BACK_BCM super().__init__(**kwargs) self.spi_port = spi_port self._sensor = None self._events_per_sec = {} self.x, self.y = (0, 0) try: if isinstance(rotation, int): rotation = [r for r in Rotation if r.value == rotation][0] self.rotation = rotation except IndexError: raise ValueError('{} is not a valid value for rotation - possible values: {}'.format( rotation, [r.value for r in Rotation])) try: if isinstance(spi_slot, str): spi_slot = [s for s in SPISlot if s.value == spi_slot][0] if spi_slot == SPISlot.FRONT: self.spi_slot = BG_CS_FRONT_BCM else: self.spi_slot = BG_CS_BACK_BCM except IndexError: raise ValueError('{} is not a valid value for spi_slot - possible values: {}'.format( spi_slot, [s.value for s in SPISlot]))
def _get_sensor(self): from pmw3901 import PMW3901 if not self._sensor: self._sensor = PMW3901(spi_port=self.spi_port, spi_cs=1, spi_cs_gpio=self.spi_slot) self._sensor.set_rotation(self.rotation) return self._sensor
[docs] @action def get_measurement(self): """ :returns: dict. Example: .. code-block:: python output = { "motion_x": 3, # Detected motion vector X-coord "motion_y": 4, # Detected motion vector Y-coord "motion_mod": 5 # Detected motion vector module "motion_events_per_sec": 7 # Number of motion events detected in the last second } """ sensor = self._get_sensor() while True: try: x, y = sensor.get_motion() break except RuntimeError: time.sleep(0.01) secs = int(time.time()) if (x, y) != (self.x, self.y): (self.x, self.y) = (x, y) if secs not in self._events_per_sec: self._events_per_sec = {secs: 1} else: self._events_per_sec[secs] += 1 return { 'motion_x': x, 'motion_y': y, 'motion_mod': math.sqrt(x * x + y * y), 'motion_events_per_sec': self._events_per_sec.get(secs, 0), }
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