CHIP_IO/docs/pwm.md

CHIP_IO.PWM

Import the PWM module as follows

import CHIP_IO.PWM as PWM

For the CHIP, this requires the PWM0 DTBO loaded via the OverlayManager or other means. For the CHIP, PWM1 is unavaiable For the CHIP Pro, PWM0 and PWM1 are setup in the base DTB by default

toggle_debug()

Enable/Disable the Debug

• Parameters

  None

• Examples

  PWM.toggle_debug()
  

is_chip_pro()

Function to report to the calling script if the SBC is a CHIP or a CHIP Pro

• Parameters

  None

• Returns

  int - 1 for CHIP Pro, 0 for CHIP

• Examples

  is_chip_pro = PWM.is_chip_pro()
  

start(channel, duty_cycle=0.0, frequency=2000.0, polarity=0)

Start the Software PWM

• Parameters

  channel - pin for software PWM is configured duty_cycle - initial duty cycle of the PWM (optional) frequency - frequency of the PWM (optional) polarity - signal polarity of the PWM (optional)

• Returns

  None

• Examples

  PWM.start("PWM0")
  PWM.start("PWM0", 37.0)
  PWM.start("PWM0", 10.0, 500.0)
  PWM.start("PWM0", 50.0, 1000.0, 1)
  

stop(channel)

Stop the PWM

• Parameters

  channel - pin PWM is configured

• Returns

  None

• Examples

  PWM.stop("PWM0")
  

set_duty_cycle(channel, duty_cycle)

Set the duty cycle of the PWM

• Parameters

  channel - pin PWM is configured duty_cycle - duty cycle of the PWM (0.0 to 100.0)

• Returns

  None

• Examples

  PWM.set_duty_cycle("PWM0", 25.0)
  

set_pulse_width_ns(channel, pulse_width_ns)

Set the width of the PWM pulse in nano seconds

• Parameters

  channel - pin PWM is configured pulse_width_ns - pulse width of the PWM in nanoseconds

• Returns

  None

• Examples

  PWM.set_pulse_width_ns("PWM0", 2500.0)
  

set_frequency(channel, frequency)

Set the frequency of the PWM in Hertz

• Parameters

  channel - pin software PWM is configured frequency - frequency of the PWM

• Returns

  None

• Examples

  PWM.set_frequency("PWM0", 450.0)
  

set_period_ns(channel, pulse_width_ns)

Set the period of the PWM pulse in nano seconds

• Parameters

  channel - pin PWM is configured period_ns - period of the PWM in nanoseconds

• Returns

  None

• Examples

  PWM.set_period_ns("PWM0", 130.0)
  

cleanup(channel)

Cleanup PWM. If not channel input, all PWM will be cleaned up

• Parameters

  channel - pin PWM is configured (optional)

• Returns

  None

• Examples

  PWM.cleanup()
  PWM.cleanup("PWM0")
  

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