Skip to content
Get started

RP2040 PWM Output

The rp2040_pwm output platform drives a pin with the hardware PWM of the RP2040 and RP2350, so the signal keeps running without any work from the main loop. Use it for dimmable lights, fan speed control, passive buzzers and anything else that takes a duty cycle.

# Example configuration entry
output:
  - platform: rp2040_pwm
    pin: GPIOXX
    frequency: 1kHz
    id: pwm_output


# Example usage in a light
light:
  - platform: monochromatic
    output: pwm_output
    name: "Kitchen Light"

Configuration variables

Section titled “Configuration variables”
  • pin (Required, Pin Schema): The pin to output the PWM signal on.
  • id (Required, ID): The id to use for this output component.
  • frequency (Optional, frequency): The frequency of the PWM signal. Lower frequencies allow a finer duty cycle resolution; at very high frequencies only a few duty cycle steps remain. Defaults to 1kHz.
  • All other options from Output.

NOTE

A PWM slice serves four pins. For GPIO0 to GPIO31 that is an adjacent pair and the pair 16 higher: GPIO0, GPIO1, GPIO16 and GPIO17 are slice 0, GPIO2, GPIO3, GPIO18 and GPIO19 are slice 1, and so on. On the RP2350, GPIO32 to GPIO47 have their own four slices, where the pair 8 higher shares instead: GPIO32, GPIO33, GPIO40 and GPIO41 are one slice. All outputs on a slice run at one frequency, so they must use the same frequency: when one of them changes it, the others still scale their duty cycle for the old frequency and can end up fully on. Give an output whose frequency changes at runtime a slice of its own. Pins that share a slice and have the same parity are the same PWM channel and output the same signal: GPIO0 and GPIO16 below GPIO32, GPIO32 and GPIO40 above it.

output.rp2040_pwm.set_frequency Action

Section titled “output.rp2040_pwm.set_frequency Action”

This Action changes the frequency of a PWM output at runtime, for example to control the pitch of a passive buzzer.

on_...:
  - output.rp2040_pwm.set_frequency:
      id: pwm_output
      frequency: 100Hz

Configuration variables:

  • id (Required, ID): The ID of the PWM output to change.
  • frequency (Required, templatable, frequency): The frequency to set.

See Also

Section titled “See Also”