PWM Manager

Enums

The following enums are used in this class. See the Enums page for details:

  • LogicLevel

PWMManager Class

The PWMManager class provides methods to control the hardware PWM channels (BCM Pin 18, and Pin 19).

Methods

  • Constructor:

    Initializes the PWMManager class, the PWM pins are in an unknown state until they are setup.

    Example:

    PWM_manager = gpio_manager.PWMManager()
  • setup_pwm_channel:
    Sets up a PWM channel with the specified parameters.

    The value of frequency_hz and duty_cycle overwrites period_ms and pulse_width_ms if they are set. If neither frequency_hz or period_ms are set, the default value of 1000 hz is used. if neither duty_cycle or pulse_width_ms are set, the default value of 0% is used.

    Parameters:

    • channel_num (int): The PWM channel number (0-3 depending on your pi model).

    • frequency_hz (Optional[float]): Frequency in Hertz. Default: 1000.

    • duty_cycle (Optional[float]): Duty cycle as a percentage (0-100). Default: 0.

    • period_ms (Optional[float]): Period in milliseconds. Default: 1.

    • pulse_width_ms (Optional[float]): Pulse width in milliseconds. Default: 0.

    • logic_level (Optional[LogicLevel]): Logic level of the PWM signal (HIGH, LOW). Default: HIGH.

    • reset_on_exit (bool): If True, the PWM channel will be reset when the pwm channel is no longer used. Default: True.

    Example:

    PWM_manager.setup_pwm_channel(channel_num=0, frequency_hz=1000, duty_cycle=50)
PWM_manager.setup_pwm_channel(channel_num=1, period_ms=1000, pulse_width_ms=500)
  • set_reset_on_exit:

    Sets the reset_on_exit flag for the given pin. If set the pin will be reset to its default state when the pin is no longer in use. Calling cleanup() or reset() will also ensure that the pin is reset to its default state.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    • reset_on_exit (bool): Whether to reset the pin to its default state when it is no longer in use.

    Example:

    PWM_manager.set_reset_on_exit(channel_num=0, reset_on_exit=False)
  • start_pwm_channel:

    Starts the PWM signal on the specified channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    Example:

    PWM_manager.start_pwm_channel(channel_num=0)
  • stop_pwm_channel:

    Stops the PWM signal.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    Example:

    PWM_manager.stop_pwm_channel(channel_num=0)
  • reset_pwm_channel:

    Resets the PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    Example:

    PWM_manager.reset_pwm_channel(channel_num=0)
  • set_duty_cycle:

    Sets the duty cycle for the specified PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    • duty_cycle (float): Duty cycle as a percentage (0-100).

    Example:

    PWM_manager.set_duty_cycle(channel_num=0, duty_cycle=75)
  • set_frequency:

    Sets the frequency for the specified PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    • frequency_hz (float): Frequency in Hertz.

    Example:

    PWM_manager.set_frequency(channel_num=0, frequency_hz=2000)
  • get_frequency:

    Gets the current frequency of the specified PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    Returns: - (float): The current frequency in Hertz.

    Example:

    current_frequency = PWM_manager.get_frequency(channel_num=0)
  • get_duty_cycle:

    Gets the current duty cycle of the specified PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    Returns: - (float): The current duty cycle as a percentage (0-100).

    Example:

    current_duty_cycle = PWM_manager.get_duty_cycle(channel_num=0)
  • set_pulse_width:

    Sets the pulse width for the specified PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    • pulse_width_ms (float): Pulse width in milliseconds.

    Example:

    PWM_manager.set_pulse_width(channel_num=0, pulse_width_ms=500)
  • get_pulse_width:

    Gets the current pulse width of the specified PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    Returns: - (float): The current pulse width in milliseconds.

    Example:

    current_pulse_width = PWM_manager.get_pulse_width(channel_num=0)
  • set_period:

    Sets the period for the specified PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    • period_ms (float): Period in milliseconds.

    Example:

    PWM_manager.set_period(channel_num=0, period_ms=20)
  • get_period:

    Gets the current period of the specified PWM channel.

    Parameters:

    • channel_num (int): The PWM channel number (0 or 1).

    Returns: - (float): The current period in milliseconds.

    Example:

    current_period = PWM_manager.get_period(channel_num=0)
  • cleanup:

    Cleans up all PWM channels.

    Example:

    PWM_manager.cleanup()