# vim: set fileencoding=utf-8:
from __future__ import (
unicode_literals,
print_function,
absolute_import,
division,
)
str = type('')
import os
import io
import subprocess
from datetime import datetime, time
from .devices import Device
from .mixins import EventsMixin
[docs]class InternalDevice(EventsMixin, Device):
"""
Extends :class:`Device` to provide a basis for devices which have no
specific hardware representation. These are effectively pseudo-devices and
usually represent operating system services like the internal clock, file
systems or network facilities.
"""
[docs]class PingServer(InternalDevice):
"""
Extends :class:`InternalDevice` to provide a device which is active when a
*host* on the network can be pinged.
The following example lights an LED while a server is reachable (note the
use of :attr:`~SourceMixin.source_delay` to ensure the server is not
flooded with pings)::
from gpiozero import PingServer, LED
from signal import pause
server = PingServer('my-server')
led = LED(4)
led.source_delay = 1
led.source = server.values
pause()
:param str host:
The hostname or IP address to attempt to ping.
"""
def __init__(self, host):
self.host = host
super(PingServer, self).__init__()
self._fire_events()
def __repr__(self):
return '<gpiozero.PingDevice host="%s">' % self.host
@property
def value(self):
# XXX This is doing a DNS lookup every time it's queried; should we
# call gethostbyname in the constructor and ping that instead (good
# for consistency, but what if the user *expects* the host to change
# address?)
with io.open(os.devnull, 'wb') as devnull:
try:
subprocess.check_call(
['ping', '-c1', self.host],
stdout=devnull, stderr=devnull)
except subprocess.CalledProcessError:
return False
else:
return True
[docs]class CPUTemperature(InternalDevice):
"""
Extends :class:`InternalDevice` to provide a device which is active when
the CPU temperature exceeds the *threshold* value.
The following example plots the CPU's temperature on an LED bar graph::
from gpiozero import LEDBarGraph, CPUTemperature
from signal import pause
# Use minimums and maximums that are closer to "normal" usage so the
# bar graph is a bit more "lively"
temp = CPUTemperature(min_temp=50, max_temp=90)
graph = LEDBarGraph(5, 6, 13, 19, 25, pwm=True)
graph.source = temp.values
pause()
:param str sensor_file:
The file from which to read the temperature. This defaults to the
sysfs file :file:`/sys/class/thermal/thermal_zone0/temp`. Whatever
file is specified is expected to contain a single line containing the
temperature in milli-degrees celsius.
:param float min_temp:
The temperature at which :attr:`value` will read 0.0. This defaults to
0.0.
:param float max_temp:
The temperature at which :attr:`value` will read 1.0. This defaults to
100.0.
:param float threshold:
The temperature above which the device will be considered "active".
This defaults to 80.0.
"""
def __init__(self, sensor_file='/sys/class/thermal/thermal_zone0/temp',
min_temp=0.0, max_temp=100.0, threshold=80.0):
self.sensor_file = sensor_file
super(CPUTemperature, self).__init__()
self.min_temp = min_temp
self.max_temp = max_temp
self.threshold = threshold
self._fire_events()
def __repr__(self):
return '<gpiozero.CPUTemperature temperature=%.2f>' % self.temperature
@property
def temperature(self):
"""
Returns the current CPU temperature in degrees celsius.
"""
with io.open(self.sensor_file, 'r') as f:
return float(f.readline().strip()) / 1000
@property
def value(self):
"""
Returns the current CPU temperature as a value between 0.0
(representing the *min_temp* value) and 1.0 (representing the
*max_temp* value). These default to 0.0 and 100.0 respectively, hence
:attr:`value` is :attr:`temperature` divided by 100 by default.
"""
temp_range = self.max_temp - self.min_temp
return (self.temperature - self.min_temp) / temp_range
@property
def is_active(self):
"""
Returns ``True`` when the CPU :attr:`temperature` exceeds the
:attr:`threshold`.
"""
return self.temperature > self.threshold
[docs]class TimeOfDay(InternalDevice):
"""
Extends :class:`InternalDevice` to provide a device which is active when
the computer's clock indicates that the current time is between
*start_time* and *end_time* (inclusive) which are :class:`~datetime.time`
instances.
The following example turns on a lamp attached to an :class:`Energenie`
plug between 7 and 8 AM::
from datetime import time
from gpiozero import TimeOfDay, Energenie
from signal import pause
lamp = Energenie(0)
morning = TimeOfDay(time(7), time(8))
morning.when_activated = lamp.on
morning.when_deactivated = lamp.off
pause()
:param ~datetime.time start_time:
The time from which the device will be considered active.
:param ~datetime.time end_time:
The time after which the device will be considered inactive.
:param bool utc:
If ``True`` (the default), a naive UTC time will be used for the
comparison rather than a local time-zone reading.
"""
def __init__(self, start_time, end_time, utc=True):
self._start_time = None
self._end_time = None
self._utc = True
super(TimeOfDay, self).__init__()
self.start_time = start_time
self.end_time = end_time
self.utc = utc
self._fire_events()
def __repr__(self):
return '<gpiozero.TimeOfDay active between %s and %s %s>' % (
self.start_time, self.end_time, ('local', 'UTC')[self.utc])
@property
def start_time(self):
"""
The time of day after which the device will be considered active.
"""
return self._start_time
@start_time.setter
def start_time(self, value):
if isinstance(value, datetime):
value = value.time()
if not isinstance(value, time):
raise ValueError('start_time must be a datetime, or time instance')
self._start_time = value
@property
def end_time(self):
"""
The time of day after which the device will be considered inactive.
"""
return self._end_time
@end_time.setter
def end_time(self, value):
if isinstance(value, datetime):
value = value.time()
if not isinstance(value, time):
raise ValueError('end_time must be a datetime, or time instance')
self._end_time = value
@property
def utc(self):
"""
If ``True``, use a naive UTC time reading for comparison instead of a
local timezone reading.
"""
return self._utc
@utc.setter
def utc(self, value):
self._utc = bool(value)
@property
def value(self):
if self.utc:
return self.start_time <= datetime.utcnow().time() <= self.end_time
else:
return self.start_time <= datetime.now().time() <= self.end_time