Set Device

Category: Action

Controls a HomeKit device — turn a light on/off, set brightness, adjust thermostat temperature, lock a door, or change any writable characteristic.

When to use

• Turn lights on or off
• Set brightness, colour temperature, or hue
• Adjust thermostat target temperature
• Lock or unlock a door
• Control any HomeKit device characteristic

Configuration

• Device — Select the accessory to control
• Characteristic — Choose which property to set (e.g. power_state, brightness, target_temperature)
• Value — The value to set. Supports:
  • Fixed values: 1, 80, 22.5
  • Template expressions: {{ trigger.to_value }}, {{ nodes.code1.data.result }}

The value input adapts to the characteristic type:

• On/off characteristics show a toggle switch
• Numeric ranges show a slider
• Enum values show a dropdown

Output data

• {{ nodes['<id>'].data.success }} — true if the device was set successfully
• {{ nodes['<id>'].data.value }} — The value that was sent
• {{ nodes['<id>'].data.accessoryId }} — The device ID
• {{ nodes['<id>'].data.characteristicType }} — The characteristic that was set

Examples

Set brightness from an HTTP response:

1. HTTP Request → GET weather API
2. Code → calculate brightness based on time of day
3. Set Device → living room light, brightness = {{ nodes.code1.data.brightness }}

Mirror one device to another:

1. Device Changed → switch A turns on
2. Set Device → switch B, power_state = {{ trigger.to_value }}

Tips

• The value field supports template expressions — use {{ }} to reference data from upstream nodes
• If the device is unreachable, the action will fail — use onError: continue to proceed anyway
• Setting a device takes a moment — HomeKit operations are asynchronous