+++ /dev/null
-"""Custom PWMOut Wrapper for Rpi.GPIO PWM Class"""
-import RPi.GPIO as GPIO
-
-GPIO.setmode(GPIO.BCM) # Use BCM pins D4 = GPIO #4
-GPIO.setwarnings(False) # shh!
-
-
-# pylint: disable=unnecessary-pass
-class PWMError(IOError):
- """Base class for PWM errors."""
-
- pass
-
-
-# pylint: enable=unnecessary-pass
-
-
-class PWMOut:
- """Pulse Width Modulation Output Class"""
-
- def __init__(self, pin, *, frequency=500, duty_cycle=0, variable_frequency=False):
- self._pwmpin = None
- self._period = 0
- self._open(pin, duty_cycle, frequency, variable_frequency)
-
- def __del__(self):
- self.deinit()
-
- def __enter__(self):
- return self
-
- def __exit__(self, t, value, traceback):
- self.deinit()
-
- def _open(self, pin, duty=0, freq=500, variable_frequency=False):
- self._pin = pin
- GPIO.setup(pin.id, GPIO.OUT)
- self._pwmpin = GPIO.PWM(pin.id, freq)
-
- if variable_frequency:
- print("Variable Frequency is not supported, continuing without it...")
-
- # set frequency
- self.frequency = freq
- # set duty
- self.duty_cycle = duty
-
- self.enabled = True
-
- def deinit(self):
- """Deinit the PWM."""
- if self._pwmpin is not None:
- self._pwmpin.stop()
- GPIO.cleanup(self._pin.id)
- self._pwmpin = None
-
- def _is_deinited(self):
- if self._pwmpin is None:
- raise ValueError(
- "Object has been deinitialize and can no longer "
- "be used. Create a new object."
- )
-
- @property
- def period(self):
- """Get or set the PWM's output period in seconds.
-
- Raises:
- PWMError: if an I/O or OS error occurs.
- TypeError: if value type is not int or float.
-
- :type: int, float
- """
- return 1.0 / self.frequency
-
- @period.setter
- def period(self, period):
- if not isinstance(period, (int, float)):
- raise TypeError("Invalid period type, should be int or float.")
-
- self.frequency = 1.0 / period
-
- @property
- def duty_cycle(self):
- """Get or set the PWM's output duty cycle which is the fraction of
- each pulse which is high. 16-bit
-
- Raises:
- PWMError: if an I/O or OS error occurs.
- TypeError: if value type is not int or float.
- ValueError: if value is out of bounds of 0.0 to 1.0.
-
- :type: int, float
- """
- return int(self._duty_cycle * 65535)
-
- @duty_cycle.setter
- def duty_cycle(self, duty_cycle):
- if not isinstance(duty_cycle, (int, float)):
- raise TypeError("Invalid duty cycle type, should be int or float.")
-
- if not 0 <= duty_cycle <= 65535:
- raise ValueError("Invalid duty cycle value, should be between 0 and 65535")
-
- # convert from 16-bit
- duty_cycle /= 65535.0
-
- self._duty_cycle = duty_cycle
- self._pwmpin.ChangeDutyCycle(round(self._duty_cycle * 100))
-
- @property
- def frequency(self):
- """Get or set the PWM's output frequency in Hertz.
-
- Raises:
- PWMError: if an I/O or OS error occurs.
- TypeError: if value type is not int or float.
-
- :type: int, float
- """
-
- return self._frequency
-
- @frequency.setter
- def frequency(self, frequency):
- if not isinstance(frequency, (int, float)):
- raise TypeError("Invalid frequency type, should be int or float.")
-
- self._pwmpin.ChangeFrequency(round(frequency))
- self._frequency = frequency
-
- @property
- def enabled(self):
- """Get or set the PWM's output enabled state.
-
- Raises:
- PWMError: if an I/O or OS error occurs.
- TypeError: if value type is not bool.
-
- :type: bool
- """
- return self._enabled
-
- @enabled.setter
- def enabled(self, value):
- if not isinstance(value, bool):
- raise TypeError("Invalid enabled type, should be string.")
-
- if value:
- self._pwmpin.start(round(self._duty_cycle * 100))
- else:
- self._pwmpin.stop()
-
- self._enabled = value
-
- # String representation
- def __str__(self):
- return "pin %s (freq=%f Hz, duty_cycle=%f%%)" % (
- self._pin,
- self.frequency,
- self.duty_cycle,
- )