+import os
+import digitalio
+
+try:
+ from microcontroller.pin import pwmOuts
+except ImportError:
+ raise RuntimeError("No PWM outputs defined for this board")
+
+from microcontroller.pin import Pin
+
+class PWMError(IOError):
+ """Base class for PWM errors."""
+ pass
+
+
+class PWMOut(object):
+ # Nova instance
+ _nova = None
+ MAX_CYCLE_LEVEL = 1024
+
+ def __init__(self, pin, *, frequency=750, duty_cycle=0, variable_frequency=False):
+ """Instantiate a PWM object and open the sysfs PWM corresponding to the
+ specified channel and pin.
+
+ Args:
+ pin (Pin): CircuitPython Pin object to output to
+ duty_cycle (int) : The fraction of each pulse which is high. 16-bit
+ frequency (int) : target frequency in Hertz (32-bit)
+ variable_frequency (bool) : True if the frequency will change over time
+
+ Returns:
+ PWMOut: PWMOut object.
+
+ Raises:
+ PWMError: if an I/O or OS error occurs.
+ TypeError: if `channel` or `pin` types are invalid.
+ ValueError: if PWM channel does not exist.
+
+ """
+ if PWMOut._nova is None:
+ if Pin._nova is not None:
+ # check if Pin already connected to Binho Nova
+ PWMOut._nova = Pin._nova
+ else:
+ from binhoHostAdapter import binhoHostAdapter
+ from binhoHostAdapter import binhoUtilities
+
+ utilities = binhoUtilities.binhoUtilities()
+ devices = utilities.listAvailableDevices()
+
+ if len(devices) > 0:
+ PWMOut._nova = binhoHostAdapter.binhoHostAdapter(devices[0])
+ else:
+ raise RuntimeError('No Binho Host Adapter found!')
+
+ self._pwmpin = None
+ 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=750, variable_frequency=False):
+ self._channel = None
+ for pwmpair in pwmOuts:
+ if pwmpair[1] == pin:
+ self._channel = pwmpair[0][0]
+ self._pwmpin = pwmpair[0][1]
+
+ self._pin = pin
+ if self._channel is None:
+ raise RuntimeError("No PWM channel found for this Pin")
+
+ PWMOut._nova.setIOpinMode(self._pwmpin, Pin.PWM)
+
+ # set frequency
+ self.frequency = freq
+ PWMOut._nova.setIOpinPWMFreq(self._pwmpin, self.frequency)
+ # set period
+ self._period = self._get_period()
+
+ # set duty
+ self.duty_cycle = duty
+
+ self._set_enabled(True)
+
+ def deinit(self):
+ try:
+ """Deinit the Nova PWM."""
+ 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
+
+ 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.")
+
+ # Mutable properties
+
+ def _get_period(self):
+ return 1.0 / self._get_frequency()
+
+ def _set_period(self, period):
+ if not isinstance(period, (int, float)):
+ raise TypeError("Invalid period type, should be int or float.")
+
+ self._set_frequency(1.0 / period)
+
+ period = property(_get_period, _set_period)
+
+ """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
+ """
+
+ def _get_duty_cycle(self):
+ duty_cycle = Pin._nova.getIOpinValue(self._pwmpin)
+
+ # Convert duty cycle to ratio from 0.0 to 1.0
+ duty_cycle = duty_cycle / PWMOut.MAX_CYCLE_LEVEL
+
+ # convert to 16-bit
+ duty_cycle = int(duty_cycle * 65535)
+ return duty_cycle
+
+ def _set_duty_cycle(self, duty_cycle):
+ if not isinstance(duty_cycle, (int, float)):
+ raise TypeError("Invalid duty cycle type, should be int or float.")
+
+ # convert from 16-bit
+ duty_cycle /= 65535.0
+ if not 0.0 <= duty_cycle <= 1.0:
+ raise ValueError("Invalid duty cycle value, should be between 0.0 and 1.0.")
+
+ # Convert duty cycle from ratio to 1024 levels
+ duty_cycle = duty_cycle * PWMOut.MAX_CYCLE_LEVEL
+
+ # Set duty cycle
+ Pin._nova.setIOpinValue(self._pwmpin, duty_cycle)
+
+ duty_cycle = property(_get_duty_cycle, _set_duty_cycle)
+ """Get or set the PWM's output duty cycle as a ratio from 0.0 to 1.0.
+
+ 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
+ """
+
+ def _get_frequency(self):
+ return int(PWMOut._nova.getIOpinPWMFreq(self._pwmpin).split('PWMFREQ ')[1])
+
+ def _set_frequency(self, frequency):
+ if not isinstance(frequency, (int, float)):
+ raise TypeError("Invalid frequency type, should be int or float.")
+
+ PWMOut._nova.setIOpinPWMFreq(self._pwmpin, frequency)
+
+ frequency = property(_get_frequency, _set_frequency)
+ """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
+ """
+
+ def _get_enabled(self):
+ enabled = self._enable
+
+ if enabled == "1":
+ return True
+ elif enabled == "0":
+ return False
+
+ raise PWMError(None, "Unknown enabled value: \"%s\"" % enabled)
+
+ def _set_enabled(self, value):
+ if not isinstance(value, bool):
+ raise TypeError("Invalid enabled type, should be string.")
+ self._enable = value
+ if not self._enable:
+ self._set_duty_cycle(0.0)
+ """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._pin, self._pin, self.frequency, self.duty_cycle * 100,)
projects / Adafruit_Blinka-hackapet.git / commitdiff