PWM / DAC Actions

Action Types

Action	actionType	Description
ACTION_SET_PWM	4	Set PWM duty cycle
ACTION_SET_DAC	5	Set DAC output value

Configuration Examples

Method 1: Web Interface Configuration (Recommended)

The peripheral execution page is shown below. When configuring PWM/DAC actions, verify the target peripheral, duty cycle range, and whether to use the trigger received value.

Example 1: Set PWM Duty Cycle (LED Dimming)

Scenario: Set LED brightness to 50% (duty cycle 128/255)

Configuration Steps:

1. Edit the rule in the Peripheral Execution Management page

2. Click the Add Action button

3. Fill in the action configuration:

   Field	Value	Description
   Action Type	Select Set PWM	PWM output
   Target Peripheral	Select led_pwm	PWM output peripheral
   Duty Cycle Value	128	8-bit resolution 0-255

4. Click the Save button

💡 Tip: Duty cycle range depends on the peripheral's configured pwmResolution: 8-bit→0~255, 12-bit→0~4095

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Example 2: Use Received Value to Dynamically Set PWM

Scenario: Dynamically control motor speed based on platform-delivered value

Configuration Steps:

1. Edit the rule, add an action

2. Fill in:

   • Action Type: Select Set PWM
   • Target Peripheral: Select motor_pwm
   • Use Received Value: ✅ Enabled
   • Note: The value passed at trigger time will be used as the PWM value

3. Click Save

💡 Tip: When "Use Received Value" is enabled, the platform sending [{"id":"motor_pwm","value":"200"}] will directly set it as the PWM value

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Example 3: Set DAC Output Value

Scenario: Set DAC output voltage (ESP32 only supports GPIO25/26)

Configuration Steps:

1. Edit the rule, add an action

2. Fill in:

   • Action Type: Select Set DAC
   • Target Peripheral: Select dac1
   • Output Value: 200 (range 0-255, 8-bit resolution)

3. Click Save

💡 Tip: ESP32 DAC is 8-bit; values 0-255 correspond to voltage 0-3.3V

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Method 2: JSON Configuration File Import

Compatible Peripheral Types

Action	Compatible Peripheral type
ACTION_SET_PWM	GPIO_PWM_OUTPUT(17), PWM_SERVO(41)
ACTION_SET_DAC	DAC(27)

Precautions

1. PWM Range: Values exceeding the resolution range will be clamped to the maximum value
2. DAC Pins: ESP32 only supports DAC output on GPIO 25/26
3. Servo Control: PWM_SERVO peripheral sets the pulse width corresponding to the angle via ACTION_SET_PWM