mirror of
https://github.com/KevinMidboe/python-gpiozero.git
synced 2025-10-29 17:50:37 +00:00
4cc4b1c132
Move the API to the end, recipes all grouped together up-front (with remote GPIO setup just before the remote GPIO recipes). Tweak some headings so everything looks a little more consistent in the (now shorter) ToC. Also added module index tags.
74 lines
2.3 KiB
ReStructuredText
74 lines
2.3 KiB
ReStructuredText
================
|
|
Advanced Recipes
|
|
================
|
|
|
|
.. currentmodule:: gpiozero
|
|
|
|
The following recipes demonstrate some of the capabilities of the GPIO Zero
|
|
library. Please note that all recipes are written assuming Python 3. Recipes
|
|
*may* work under Python 2, but no guarantees!
|
|
|
|
Travis build LED indicator
|
|
==========================
|
|
|
|
Use LEDs to indicate the status of a Travis build. A green light means the
|
|
tests are passing, a red light means the build is broken:
|
|
|
|
.. literalinclude:: examples/led_travis.py
|
|
|
|
Note this recipe requires `travispy`_. Install with ``sudo pip3 install
|
|
travispy``.
|
|
|
|
Button controlled robot
|
|
=======================
|
|
|
|
Alternatively, use four buttons to program the directions and add a fifth
|
|
button to process them in turn, like a Bee-Bot or Turtle robot.
|
|
|
|
.. literalinclude:: examples/robot_buttons_2.py
|
|
|
|
Controlling the Pi's own LEDs
|
|
=============================
|
|
|
|
On certain models of Pi (specifically the model A+, B+, and 2B) it's possible
|
|
to control the power and activity LEDs. This can be useful for testing GPIO
|
|
functionality without the need to wire up your own LEDs (also useful because
|
|
the power and activity LEDs are "known good").
|
|
|
|
Firstly you need to disable the usual triggers for the built-in LEDs. This can
|
|
be done from the terminal with the following commands:
|
|
|
|
.. code-block:: console
|
|
|
|
$ echo none | sudo tee /sys/class/leds/led0/trigger
|
|
$ echo gpio | sudo tee /sys/class/leds/led1/trigger
|
|
|
|
Now you can control the LEDs with gpiozero like so:
|
|
|
|
.. literalinclude:: examples/led_builtin.py
|
|
|
|
To revert the LEDs to their usual purpose you can either reboot your Pi or
|
|
run the following commands:
|
|
|
|
.. code-block:: console
|
|
|
|
$ echo mmc0 | sudo tee /sys/class/leds/led0/trigger
|
|
$ echo input | sudo tee /sys/class/leds/led1/trigger
|
|
|
|
.. note::
|
|
|
|
On the Pi Zero you can control the activity LED with this recipe, but
|
|
there's no separate power LED to control (it's also worth noting the
|
|
activity LED is active low, so set ``active_high=False`` when constructing
|
|
your LED component).
|
|
|
|
On the original Pi 1 (model A or B), the activity LED can be controlled
|
|
with GPIO16 (after disabling its trigger as above) but the power LED is
|
|
hard-wired on.
|
|
|
|
On the Pi 3B the LEDs are controlled by a GPIO expander which is not
|
|
accessible from gpiozero (yet).
|
|
|
|
|
|
.. _travispy: https://travispy.readthedocs.io/
|