# pylint: disable=invalid-name # SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries # # SPDX-License-Identifier: MIT # pylint: enable=invalid-name """ PWMOut Class for lgpio lg library tx_pwm library """ import lgpio import board # need board to get access to the CHIP object in the pin module # pylint: disable=unnecessary-pass class PWMError(IOError): """Base class for PWM errors.""" pass # pylint: enable=unnecessary-pass class PWMOut: # pylint: disable=invalid-name """Pulse Width Modulation Output Class""" def __init__(self, pin, *, frequency=500, duty_cycle=0, variable_frequency=False): if variable_frequency: print("Variable Frequency is not supported, ignoring...") self._pin = pin result = lgpio.gpio_claim_output( board.pin.CHIP, self._pin.id, lFlags=lgpio.SET_PULL_NONE ) if result < 0: raise RuntimeError(lgpio.error_text(result)) self._enabled = False self._deinited = False self._period = 0 # set frequency self._frequency = frequency # set duty self.duty_cycle = duty_cycle self.enabled = True def __del__(self): self.deinit() def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.deinit() def deinit(self): """Deinit the PWM.""" if not self._deinited: if self.enabled: self._enabled = False # turn off the pwm self._deinited = True def _is_deinited(self): """raise Value error if the object has been de-inited""" if self._deinited: 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 if self._enabled: self.enabled = True # turn on with new values @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._frequency = frequency if self.enabled: self.enabled = True # turn on with new values @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 bool.") frequency = self._frequency if value else 0 duty_cycle = round(self._duty_cycle * 100) self._enabled = value result = lgpio.tx_pwm(board.pin.CHIP, self._pin.id, frequency, duty_cycle) if result < 0: raise RuntimeError(lgpio.error_text(result)) return result # String representation def __str__(self): return ( f"pin {self._pin} (freq={self.frequency:f} Hz, duty_cycle=" f"{self.duty_cycle}({round(self.duty_cycle / 655.35)}%)" )