Files
python-gpiozero/gpiozero/input_devices.py
Dave Jones 1219d99ded Fix #8
Make the pin property a read-only property
2015-09-17 10:50:23 +01:00

129 lines
3.5 KiB
Python

from __future__ import division
from time import sleep
from threading import Thread, Event
from collections import deque
from RPi import GPIO
from w1thermsensor import W1ThermSensor
class InputDevice(object):
def __init__(self, pin=None):
if pin is None:
raise InputDeviceError('No GPIO pin number given')
self._pin = pin
self._pull = GPIO.PUD_UP
self._edge = GPIO.FALLING
self._active_state = 0
self._inactive_state = 1
GPIO.setup(pin, GPIO.IN, self._pull)
@property
def pin(self):
return self._pin
@property
def is_active(self):
return GPIO.input(self.pin) == self._active_state
def wait_for_input(self):
GPIO.wait_for_edge(self.pin, self._edge)
def add_callback(self, callback=None, bouncetime=1000):
if callback is None:
raise InputDeviceError('No callback function given')
GPIO.add_event_detect(self.pin, self._edge, callback, bouncetime)
def remove_callback(self):
GPIO.remove_event_detect(self.pin)
class Button(InputDevice):
pass
class MotionSensor(InputDevice):
def __init__(self, pin=None, queue_len=20, sample_rate=10, partial=False):
super(MotionSensor, self).__init__(pin)
self._sample_rate = sample_rate
self._partial = partial
self._queue = deque(maxlen=queue_len)
self._queue_full = Event()
self._terminated = False
self._queue_thread = Thread(target=self._fill_queue)
self._queue_thread.start()
def __del__(self):
self._terminated = True
self._queue_thread.join()
def _fill_queue(self):
while not self._terminated and len(self._queue) < self._queue.maxlen:
self._queue.append(self.is_active)
sleep(1 / self._sample_rate)
self._queue_full.set()
while not self._terminated:
self._queue.append(self.is_active)
sleep(1 / self._sample_rate)
@property
def motion_detected(self):
if not self._partial:
self._queue_full.wait()
return sum(self._queue) > (len(self._queue) / 2)
class LightSensor(object):
def __init__(self, pin=None, darkness_level=0.01):
if pin is None:
raise InputDeviceError('No GPIO pin number given')
self._pin = pin
self.darkness_level = darkness_level
@property
def pin(self):
return self._pin
@property
def value(self):
return self._get_average_light_level(5)
def _get_light_level(self):
time_taken = self._time_charging_light_capacitor()
value = 100 * time_taken / self.darkness_level
return 100 - value
def _time_charging_light_capacitor(self):
GPIO.setup(self.pin, GPIO.OUT)
GPIO.output(self.pin, GPIO.LOW)
sleep(0.1)
GPIO.setup(self.pin, GPIO.IN)
start_time = time()
end_time = time()
while (
GPIO.input(self.pin) == GPIO.LOW and
time() - start_time < self.darkness_level
):
end_time = time()
time_taken = end_time - start_time
return min(time_taken, self.darkness_level)
def _get_average_light_level(self, num):
values = [self._get_light_level() for n in range(num)]
average_value = sum(values) / len(values)
return average_value
class TemperatureSensor(W1ThermSensor):
@property
def value(self):
return self.get_temperature()
class InputDeviceError(Exception):
pass