This finishes off implementing values and source for all (current)
classes in gpiozero. I'm afraid things get rather complex in this
commit. For starters, we've now got quite a few "aggregate" classes
which necessarily don't descend from GPIODevice. To implement values and
source on these I could either repeat a helluva lot of code or ... turn
to mixin classes. Yeah, it's multiple inheritance time, baby!
Unfortunately multiple inheritance doesn't work with __slots__ but we
really ought to keep functionality that they provide us (raise
AttributeError when an unknown attribute is set). So I've implemented
this with ... erm ... metaclasses. Sorry!
Makes `value` an alias of `is_active` in the base `GPIODevice`, and
`values` an infinite iterable of this value. Then adds `source` property
to `OutputDevice` allowing simple linkage of devices via iterators.
Add more property aliases and do them properly (no more lambdas and
string lookups) which means we can remove `_alias`. This commit also
defines `__slots__` for all classes which should prevent assignation of
invalid attributes with an AttributeError (more friendly than silently
doing the wrong thing). Finally, it cleans up all the property defs to
use Ben's preferred decorator style.
This PR adds the `active_high` parameter (defaulted to `True`) to the
`OutputDevice` class. This permits flipping the logic of an output
device in a similar manner to `pull_up` on `InputDevice`.
It also adds a `Relay` class derived from `DigitalOutputDevice` which
uses this parameter to flip the logic (as this is typically required
with relays).
Actually, this isn't so much a fix as a re-working of RGBLED. This
renames the `rgb` property to `color` because that's what the property
really represents (combined with `picamera.Color` this lets you do stuff
like `rgb_led.color = Color('red')`), and simplifies the internals of
the class. It also adds the common `close` method and context manager
capabilities.
Finally, it corrects an error I hadn't noticed earlier where
PWMOutputDevice isn't properly cleaning up PWM threads on close.
Make MotionSensor more responsive by effectively removing the averaging
queue. Also add note on how to smooth out "jittery" PIR sensors by
increasing the queue length back up to 5.
This refactors the GPIOOutputDevice to have an internal `_write` method
similar to the `_read` method used to grab the value of a GPIO device.
This is used for simple 1s and 0s until we get to PWMOutputDevice which
replaces the value with the PWM device's duty cycle level. As a result,
all the DigitalOutputDevice base methods (including blink) "just work".
This commit also, for the moment, removes min_pwm and max_pwm because
I'm not 100% certain how they should interact with the notion of
is_active at the moment. They'll probably get added back in at some
point but I need a bit more time to think about it!
This isn't a full fix but I can't seem to reproduce the issue in #50 at
the moment. So for now this just ensures that exceptions in the
constructors get cleaned up properly (so they don't block future
construction attempts against the same pin)
Big push on getting the docs cleaned up before 1.0. Proper wrapping of
everything so it's decently viewable from the command line (or as
decently viewable as markdown can be - the tables will never look great
from the command line).
Only one code change in this PR: rename bouncetime to bounce_time
(everything else is PEP-8, so this probably should be too) and change
its units to seconds from milliseconds (again, all other durations in
the library are in seconds, so it feels inconsistent that this one
isn't; for the sake of those who won't read the docs - which is most
people - I figure consistency helps with guessing!).
Permit devices to be explicitly closed and used as context managers.
Also deal with cleanup properly at script end and ensure objects don't
step on the global cleanup function.
Add a nice __repr__ to the GPIODevice base class.
This isn't much but generally I think `__repr__` implementations should
be deliberately simple: firstly, they're frequently used for debugging
so if they're at all complex you risk making a debugging tool buggy
(very annoying!). Secondly, if you pour too much info into them you risk
making the debugging output cluttered, so I tend to prefer keeping it to
straight-forward simple to retrieve/calculate info without excessive
detail (if the user wants more, they can always query it directly).
There is one refinement here: in SmoothedInputDevice, `__repr__` is
tweaked to ensure that when partial is False (the default), and the
queue isn't filled, `__repr__` doesn't block (because it should *never*
block).
