-# 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
+# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+"""
+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 os
-import digitalio
try:
from microcontroller.pin import pwmOuts
except ImportError:
- raise RuntimeError("No PWM outputs defined for this board")
+ raise RuntimeError("No PWM outputs defined for this board") from ImportError
+
+# pylint: disable=unnecessary-pass
class PWMError(IOError):
"""Base class for PWM errors."""
+
pass
-class PWMOut(object):
+# pylint: enable=unnecessary-pass
+
+
+class PWMOut:
+ """Pulse Width Modulation Output Class"""
+
# Sysfs paths
_sysfs_path = "/sys/class/pwm/"
_channel_path = "pwmchip{}"
"""
self._pwmpin = None
+ self._channel = None
+ self._period = 0
self._open(pin, duty_cycle, frequency, variable_frequency)
def __del__(self):
if self._channel is None:
raise RuntimeError("No PWM channel found for this Pin")
- channel_path = os.path.join(self._sysfs_path, self._channel_path.format(self._channel))
+ if variable_frequency:
+ print("Variable Frequency is not supported, continuing without it...")
+
+ channel_path = os.path.join(
+ self._sysfs_path, self._channel_path.format(self._channel)
+ )
if not os.path.isdir(channel_path):
- raise ValueError("PWM channel does not exist, check that the required modules are loaded.")
+ raise ValueError(
+ "PWM channel does not exist, check that the required modules are loaded."
+ )
- pin_path = os.path.join(channel_path, self._pin_path.format(self._channel,self._pwmpin))
+ pin_path = os.path.join(
+ channel_path, self._pin_path.format(self._channel, self._pwmpin)
+ )
if not os.path.isdir(pin_path):
try:
- with open(os.path.join(channel_path, self._export_path), "w") as f_export:
+ with open(
+ os.path.join(channel_path, self._export_path), "w", encoding="utf-8"
+ ) as f_export:
f_export.write("%d\n" % self._pwmpin)
except IOError as e:
- raise PWMError(e.errno, "Exporting PWM pin: " + e.strerror)
+ raise PWMError(e.errno, "Exporting PWM pin: " + e.strerror) from IOError
# Look up the period, for fast duty cycle updates
self._period = self._get_period()
self._set_enabled(True)
def deinit(self):
- try:
"""Deinit the sysfs PWM."""
- channel_path = os.path.join(self._sysfs_path, self._channel_path.format(self._channel))
- pin_path = os.path.join(channel_path, self._pin_path.format(self._channel,self._pwmpin))
-
- if self._channel is not None:
- #self.duty_cycle = 0
- self._set_enabled(False) # make to disable before unexport
- try:
- #unexport_path = os.path.join(channel_path, self._unexport_path)
- with open(os.path.join(channel_path, self._unexport_path), "w") as f_unexport:
- f_unexport.write("%d\n" % self._pwmpin)
- except IOError as e:
- raise PWMError(e.errno, "Unexporting PWM pin: " + e.strerror)
- except Exception as e:
- # due to a race condition for which I have not yet been
- # able to find the root cause, deinit() often fails
- # but it does not effect future usage of the pwm pin
- print("warning: failed to deinitialize pwm pin {0}:{1} due to: {2}\n".format(self._channel, self._pwmpin, type(e).__name__))
- finally:
- self._channel = None
- self._pwmpin = None
+ # pylint: disable=broad-except
+ try:
+ channel_path = os.path.join(
+ self._sysfs_path, self._channel_path.format(self._channel)
+ )
+
+ if self._channel is not None:
+ # self.duty_cycle = 0
+ self._set_enabled(False) # make to disable before unexport
+ try:
+ # unexport_path = os.path.join(channel_path, self._unexport_path)
+ with open(
+ os.path.join(channel_path, self._unexport_path),
+ "w",
+ encoding="utf-8",
+ ) as f_unexport:
+ f_unexport.write("%d\n" % self._pwmpin)
+ except IOError as e:
+ raise PWMError(
+ e.errno, "Unexporting PWM pin: " + e.strerror
+ ) from IOError
+ except Exception as e:
+ # due to a race condition for which I have not yet been
+ # able to find the root cause, deinit() often fails
+ # but it does not effect future usage of the pwm pin
+ print(
+ "warning: failed to deinitialize pwm pin {0}:{1} due to: {2}\n".format(
+ self._channel, self._pwmpin, type(e).__name__
+ )
+ )
+ finally:
+ self._channel = None
+ self._pwmpin = None
+ # pylint: enable=broad-except
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.")
+ raise ValueError(
+ "Object has been deinitialize and can no longer "
+ "be used. Create a new object."
+ )
def _write_pin_attr(self, attr, value):
# Make sure the pin is active
path = os.path.join(
self._sysfs_path,
self._channel_path.format(self._channel),
- self._pin_path.format(self._channel,self._pwmpin),
- attr)
+ self._pin_path.format(self._channel, self._pwmpin),
+ attr,
+ )
- with open(path, 'w') as f_attr:
+ with open(path, "w", encoding="utf-8") as f_attr:
f_attr.write(value + "\n")
def _read_pin_attr(self, attr):
path = os.path.join(
self._sysfs_path,
self._channel_path.format(self._channel),
- self._pin_path.format(self._channel,self._pwmpin),
- attr)
+ self._pin_path.format(self._channel, self._pwmpin),
+ attr,
+ )
- with open(path, 'r') as f_attr:
+ with open(path, "r", encoding="utf-8") as f_attr:
return f_attr.read().strip()
# Mutable properties
try:
period_ns = int(period_ns)
except ValueError:
- raise PWMError(None, "Unknown period value: \"%s\"" % period_ns)
+ raise PWMError(
+ None, 'Unknown period value: "%s"' % period_ns
+ ) from ValueError
# Convert period from nanoseconds to seconds
period = period_ns / 1e9
try:
duty_cycle_ns = int(duty_cycle_ns)
except ValueError:
- raise PWMError(None, "Unknown duty cycle value: \"%s\"" % duty_cycle_ns)
+ raise PWMError(
+ None, 'Unknown duty cycle value: "%s"' % duty_cycle_ns
+ ) from ValueError
# Convert duty cycle from nanoseconds to seconds
duty_cycle = duty_cycle_ns / 1e9
if enabled == "1":
return True
- elif enabled == "0":
+ if enabled == "0":
return False
- raise PWMError(None, "Unknown enabled value: \"%s\"" % enabled)
+ raise PWMError(None, 'Unknown enabled value: "%s"' % enabled)
def _set_enabled(self, value):
+ """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
+ """
if not isinstance(value, bool):
raise TypeError("Invalid enabled type, should be string.")
self._write_pin_attr(self._pin_enable_path, "1" if value else "0")
- """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
- """
-
# String representation
def __str__(self):
- return "PWM%d, pin %s (freq=%f Hz, duty_cycle=%f%%)" % \
- (self._channel, self._pin, self.frequency, self.duty_cycle * 100,)
+ return "PWM%d, pin %s (freq=%f Hz, duty_cycle=%f%%)" % (
+ self._channel,
+ self._pin,
+ self.frequency,
+ self.duty_cycle * 100,
+ )
projects / Adafruit_Blinka-hackapet.git / blobdiff