# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries # # SPDX-License-Identifier: MIT """Custom PWMOut Wrapper for Jetson GPIO PWM Class""" from RPi import GPIO GPIO.setmode(GPIO.TEGRA_SOC) # Use BCM pins D4 = GPIO #4 GPIO.setwarnings(True) # shh! class PWMError(IOError): """Base class for PWM errors.""" 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, initial=GPIO.HIGH) 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, )