# validated: 2016-12-27 JW aafca4ed7fff athena/java/edu/wpi/first/wpilibj/DigitalSource.java
#----------------------------------------------------------------------------
# Copyright (c) FIRST 2008-2012. All Rights Reserved.
# Open Source Software - may be modified and shared by FRC teams. The code
# must be accompanied by the FIRST BSD license file in the root directory of
# the project.
#----------------------------------------------------------------------------
import hal
import weakref
from .resource import Resource
from .sensorbase import SensorBase
from .interruptablesensorbase import InterruptableSensorBase
__all__ = ["DigitalSource"]
def _freeDigitalSource(handle):
hal.freeDIOPort(handle)
[docs]class DigitalSource(InterruptableSensorBase):
"""DigitalSource Interface. The DigitalSource represents all the possible
inputs for a counter or a quadrature encoder. The source may be either a
digital input or an analog input. If the caller just provides a channel,
then a digital input will be constructed and freed when finished for the
source. The source can either be a digital input or analog trigger but
not both.
.. not_implemented: initDigitalPort
"""
channels = Resource(SensorBase.kDigitalChannels)
def __init__(self, channel, input):
"""
:param channel: Port for the digital input
:type channel: int
:param input: True if input, False otherwise
:type input: int
"""
super().__init__()
SensorBase.checkDigitalChannel(channel)
self.channel = channel
self._handle = hal.initializeDIOPort(hal.getPort(channel), input)
try:
DigitalSource.channels.allocate(self, channel)
except IndexError as e:
raise IndexError("Digital input %d is already allocated" % self.channel) from e
self.__finalizer = weakref.finalize(self, _freeDigitalSource, self._handle)
@property
def handle(self):
if not self.__finalizer.alive:
raise ValueError("Cannot use channel after free() has been called")
return self._handle
[docs] def free(self):
DigitalSource.channels.free(self.channel)
self.__finalizer()
[docs] def isAnalogTrigger(self):
raise NotImplementedError
[docs] def getChannel(self):
raise NotImplementedError