# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries # # SPDX-License-Identifier: MIT # SPDX-FileCopyrightText: 2022 Martin Schnur for Siemens AG # # SPDX-License-Identifier: MIT # pylint: disable=pointless-string-statement # pylint: disable=ungrouped-imports,wrong-import-position,unused-import # pylint: disable=import-outside-toplevel """Custom PWMOut Wrapper for am65xx""" """ Much code from https://github.com/vsergeev/python-periphery/blob/master/periphery/pwm.py Copyright (c) 2015-2016 vsergeev / Ivan (Vanya) A. Sergeev License: MIT """ import mraa from adafruit_blinka.microcontroller.am65xx.pin import Pin # 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._frequency = None self._duty_cycle = None self._pwmpin = None self._period = 0 self._enabled = False self._varfreq = variable_frequency # check pin for PWM support self._pin = Pin(pin.id) self._pin.init(mode=Pin.PWM) # initialize pin 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._pwmpin = mraa.Pwm(pin.id) self.frequency = freq self.enabled = True self._varfreq = variable_frequency self.duty_cycle = duty def deinit(self): """Deinit the PWM.""" if self._pwmpin is not None: self._pwmpin.enable(False) 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)) self._pwmpin.write(self._duty_cycle) # mraa duty_cycle 0.0f - 1.0f @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.") if self._enabled and not self._varfreq: raise TypeError( " Set variable_frequency = True to allow changing frequency " ) # mraa has different variants in seconds,milli(_ms),micro(_us) self._pwmpin.period((1 / 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.enable(True) self._enabled = value else: self._pwmpin.enable(False) self._enabled(False) # String representation def __str__(self): return "pin %s (freq=%f Hz, duty_cycle=%f%%)" % ( self._pin, self.frequency, self.duty_cycle, )