GPIO Zero also provides several “internal” devices which represent facilities provided by the operating system itself. These can be used to react to things like the time of day, or whether a server is available on the network.
These devices are experimental and their API is not yet considered stable. We welcome any comments from testers, especially regarding new “internal devices” that you’d find useful!
TimeOfDay(start_time, end_time, utc=True)¶
The following example turns on a lamp attached to an
Energenieplug 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()
InternalDeviceto 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
source_delayto 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()
Parameters: host (str) – The hostname or IP address to attempt to ping.
CPUTemperature(sensor_file='/sys/class/thermal/thermal_zone0/temp', min_temp=0.0, max_temp=100.0, threshold=80.0)¶
InternalDeviceto 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()
- sensor_file (str) – The file from which to read the temperature. This defaults to the
/sys/class/thermal/thermal_zone0/temp. Whatever file is specified is expected to contain a single line containing the temperature in milli-degrees celsius.
- min_temp (float) – The temperature at which
valuewill read 0.0. This defaults to 0.0.
- max_temp (float) – The temperature at which
valuewill read 1.0. This defaults to 100.0.
- threshold (float) – The temperature above which the device will be considered “active”. This defaults to 80.0.
- sensor_file (str) – The file from which to read the temperature. This defaults to the sysfs file
The classes in the sections above are derived from a series of base classes, some of which are effectively abstract. The classes form the (partial) hierarchy displayed in the graph below:
The following sections document these base classes for advanced users that wish to construct classes for their own devices.