def initPWM(pin):
""" Sets a pin to PWM """
pwm = PWM(pin, 0)
pwm.frequency = 1e3
pwm.duty_cycle = 0
pwm.enable()
return pwm
def prepare(self) -> None:
logger = get_logger(0)
for (pin, initial) in self.__channels.items():
try:
logger.info("Probing pwm chip %d channel %d ...", self.__chip,
pin)
pwm = PWM(self.__chip, pin)
self.__pwms[pin] = pwm
pwm.period_ns = self.__period
pwm.duty_cycle_ns = self.__get_duty_cycle(bool(initial))
pwm.enable()
except Exception as err:
logger.error("Can't get PWM chip %d channel %d: %s",
self.__chip, pin, tools.efmt(err))
def initPWM(pin):
pwm = PWM(pin, 0)
pwm.frequency = 1e3
pwm.duty_cycle = 0
pwm.enable()
return pwm
print(mode)
# Open PWM channel 0, pin 32
pins = range(0, 41)
"""
for pin in pins:
try:
pwm = PWM(0, pin)
print("** Channel 0 pin {} works!".format(pin))
except:
print("Pin {} does not work".format(pin))
"""
pwm = PWM(0, 2)
pwm = PWM(0, 0)
#Channel 0 pin 2
# Set frequency to 1 kHz
pwm.frequency = 2e3
# Set duty cycle to 75%
pwm.duty_cycle = 0.25
pwm.enable()
# Change duty cycle to 50%
pwm.duty_cycle = 0.25
time.sleep(5 * 60)
pwm.close()
class HPWMPeriphery(HPWM):
"""Wrapper around python periphery pwm implementation extends :class:`HPWM`.
This class need the periphery module to be installed. Also some configuration
files need to be added to the system. More info in the repo's README.
Args:
pin (int): The pin number in bcm mode.
Raises:
ImportError: Error if the periphery library is not installed.
"""
_chip = 0 # PWM chip
def __init__(self, pin):
# Check if the pin is valid
super(HPWMPeriphery, self).__init__(pin)
if PWM is None:
raise ImportError("Failed to import PWM from periphery.")
self._pwm = PWM(self._chip, self._SELECTED_COMB.index(pin))
def read(self):
"""Read from hardware pwm pin.
Returns:
float: The duty cycle of the pwm pin.
"""
return self.duty_cycle
def write(self, value):
"""Write to the pwm pin.
Args:
value (float): The new duty cycle value.
"""
self.duty_cycle = value
def close(self):
self.enable = 0
def _get_frequency(self):
return self._pwm.frequency
def _set_frequency(self, frequency):
"Ugly solution to sysf permission error"
try:
self._pwm.frequency = frequency
except PermissionError:
sleep(0.1)
self._pwm.frequency = frequency
def _get_duty_cycle(self):
return self._pwm.duty_cycle
def _set_duty_cycle(self, duty_cycle):
self._pwm.duty_cycle = duty_cycle
def _get_enable(self):
return self._enable
def _set_enable(self, enable):
#self._pwm.enable = enable
self._enable = enable
if self._enable:
self._pwm.enable()
else:
self._pwm.disable()
def _get_polarity(self):
pass
def _set_polarity(self, polarity):
pass
class PERIPHERY_PWM(PERIPHERY):
"""
PWM出力ピンを表すクラス。
指定ピンがハードウェアPWMに対応しない場合は、疑似PWMとして操作する。
"""
def __init__(self, pin, freq=None, range=None, threshold=0.01, debug=False):
"""
親クラスのコンストラクタ処理後、指定のピンに対しPWM出力ピンとして設定を行う。
初期値としてPWMサイクル値をゼロに指定する。
引数：
pin int PWM番号、必須(1～3)
freq int PWM Frequency値（Hz）
range int PWMサイクル値の範囲(25から40,000までの整数)
threshold float 入力値を0として認識するしきい値(-threshold < value< threshold => 0)
"""
super().__init__(pin, mode=OUT, debug=debug)
self.freq = freq or DEFAULT_FREQ
self.threshold = threshold
if self.pin == 1:
self.chip_number = 0
self.channel_number = 0
elif self.pin == 2:
self.chip_number = 1
self.channel_number = 0
elif self.pin == 3:
self.chip_number = 2
self.channel_number = 0
else:
raise ValueError('[PERIPHERY_PWM] pwm:{} is out of range(1.. 3)'.format(str(self.pin)))
try:
from periphery import PWM
except ImportError:
exit('[PERIPHERY_PWM] This code requires periphery package')
self.gpio = PWM(self.chip_number, self.channel_number)
self.gpio.frequency = self.freq
self.gpio.duty_cycle = 0
self.gpio.enable()
self.run(0)
if self.debug:
print('[PERIPHERY_PWM] pwm:{} set freq:{}/dutycycle:{}, enabled and set value 0'.format(
str(self.pin), str(self.freq), str(self.gpio.duty_cycle)))
def run(self, input_value):
"""
引数で渡されたpulse値をPWMサイクル値に変換し、指定ピンへ出力する。
引数：
input_value float コントローラ/AIからの入力値
戻り値：
なし
"""
cycle = self.to_duty_cycle(input_value)
self.gpio.duty_cycle(cycle)
if self.debug:
print('[PERIPHERY_PWM] pwm:{} set cycle {}(input_value:{})'.format(
str(self.pin), str(cycle), str(input_value)))
def to_duty_cycle(self, input_value):
"""
コントローラ/AIからの入力値をPWMサイクル値に変換する。
しきい値範囲内の場合やNoneの場合は、0として扱う。
引数：
input_value float コントローラ/AIからの入力値（None含む）
戻り値：
cycle float PWM duty_cycle値
"""
if input_value is None or (abs(float(input_value)) < self.threshold):
if self.debug:
print('[PERIPHERY_PWM] gpio:{} input_value None to zero'.format(str(self.pin)))
return float(0)
input_value = abs(input_value)
if input_value >= 1.0:
return float(1.0)
return float(input_value)
def shutdown(self):
self.run(0)
self.gpio.disable()
if self.debug:
print('[PERIPHERY_PWM] set duty_cycle to 0 and disabled')
super().shutdown()