We're not promoting "motion everywhere." A PIR doesn't mean presence. Lux limits turning on, not holding a light on. A timer counts time since motion last stopped. The modes from Lesson 10 (Night, Movie, Guests) affect the behavior. You only turn on the global lighting_automation_enabled helper after reviewing every automation that uses it. Further on I'll shorten Home Assistant to HA.

Plan on about 115 to 125 minutes. Automations use the action: syntax.

A real-life problem: the light goes out in the bathtub

A PIR above the door, a 2-minute delay, then turn off. After two minutes in the bath, the light goes out: the sensor can't see a person behind the shower screen. Or: a household member manually turns off the light, is still standing in the hallway, and the sensor turns it back on. Or: lux rises once the lamp is on, the next motion event doesn't cancel the timer, and the light goes out despite someone being present.

These problems come from flawed logic: a delay instead of measuring time since motion actually stopped, checking lux before every click, and no distinction between a light turned on by automation and one turned on by hand.

What takes priority

1. A household member's manual control.
2. A local lockout or a manual override.
3. A special mode: Movie, Guests, Cleaning.
4. Night mode, setting the brightness.
5. Motion or presence.
6. Lux limiting automatic turn-on.
7. A timer responsible for turning it off.

PIR and mmWave: no magic involved

A PIR detects body movement. Cheap, efficient. It doesn't detect a motionless person, someone lying in a bathtub, or someone behind a wall. False triggers can come from a radiator, warm air currents, sunlight, a pet, or a poorly tuned sensitivity setting: a fluttering curtain isn't an obvious trigger for every PIR.

Humidity can support ventilation or extend a light's runtime during a bath, but it doesn't replace presence detection: it rises with a lag, lingers after someone leaves, and doesn't change for a quick trip to the toilet. A door contact sensor isn't a people counter: a closed door doesn't equal someone being there.

A cat walking through at night is a correct motion detection, not necessarily a "sensor bug." You can limit brightness or the angle if you don't want a full-brightness light in that case.

Lux only for turning on

Lux measures the light level at the mounting location. Once the lamp is lit, the reading rises: if the lux condition sits ahead of canceling the timer, the next motion event won't keep the light on. That's why: check lux only when the light is off and you're deciding whether to turn it on automatically. When the light is on, motion cancels the timer regardless of lux.

Don't carry a threshold from one model over to another. Record the reading at the moment you yourself judge the light is needed. A starting point: hallway ~30-50, a kitchen with a window higher: calibrate it. Lux unknown/unavailable: for an important passage, consider a low emergency brightness rather than no light at all; for decorative lighting, you can choose not to turn it on. In a windowless bathroom, lux often adds nothing useful: you can skip it.

The timer: on cancels, off starts it

The pattern "motion on → turn on plus start the timer" doesn't measure time since motion actually stopped. A PIR can stay on for a minute: a timer started at "on" finishes too early relative to the real absence of a person.

A better pattern: motion on → cancel the shutoff (and possibly turn on); motion off → start the timer; timer finished → confirm there's still no motion and check the owner → turn it off.

For a simple point, one automation with mode: restart and a wait for no-motion may be enough. A timer is better when you want to see the remaining time, cancel the countdown, or share it with manual control. Calling timer.start on an active timer restarts the countdown from scratch. Use timer.cancel to cancel it: timer.finish can trigger the shutoff event.

restore: true can restore an active timer after an HA restart, but if the timer expired while HA was down, the timer.finished event won't fire once it starts back up. After a restart, run a test: an active timer and an expired one, the light's state, and the helpers' states. The owner helper (hallway_light_on_by_motion) may not reflect reality: clear it whenever the light is off. For a critical hallway with lux unavailable: turn on a limited brightness and report the sensor problem.

Hallway helpers

input_boolean:
  hallway_motion_lockout:
    name: Motion lockout - hallway
    icon: mdi:motion-sensor-off

  hallway_light_on_by_motion:
    name: Hallway - light turned on by motion
    icon: mdi:motion-sensor

timer:
  hallway_light:
    name: Hallway light shutoff timer
    duration: "00:03:00"
    restore: true

  hallway_light_manual_override:
    name: Hallway light manual override
    duration: "00:30:00"
    restore: true

hallway_motion_lockout disables both automatic turn-on and turn-off: the light's current state stays put, and the household member controls it manually; cancel any active timer. In a real home, local lockouts (hallway_motion_lockout) are usually more convenient than one global one. The global lighting_automation_enabled blocks new turn-on cycles; you can leave an already-started shutoff to finish (define this deliberately). Don't turn on the global helper "just for the hallway": it's global; test with the local helper instead, or disable the other automations. If your helpers are created via the UI, don't duplicate them in YAML.

- id: hallway_lockout_cancels_timer
  alias: Hallway - motion lockout cancels the timer
  mode: single

  triggers:
    - trigger: state
      entity_id: input_boolean.hallway_motion_lockout
      to: "on"

  actions:
    - action: timer.cancel
      target:
        entity_id: timer.hallway_light

The hallway's architecture: three automations

Take the nighttime brightness from light_mode = night (Lesson 10), not from duplicated 10pm-6am windows. Brightness should be no lower than the minimum stable start level from Lesson 5. On stairs, safety takes priority over "an efficient 5%." When the light is already on: don't change a manually set brightness; only cancel the timer. Don't trigger the Evening scene from hallway motion.

- id: hallway_motion_holds_and_turns_on
  alias: Hallway - motion holds and turns on the light
  mode: restart

  triggers:
    - trigger: state
      entity_id: binary_sensor.hallway_motion
      to: "on"

  actions:
    # Cancel the timer before the master check: motion should hold an already-lit
    # light even when the master is off (master = don't start new cycles; don't
    # immediately interrupt one already running). If the master is meant to
    # "change nothing," move timer.cancel after the master/lockout conditions.
    - action: timer.cancel
      target:
        entity_id: timer.hallway_light

    - condition: state
      entity_id: input_boolean.lighting_automation_enabled
      state: "on"

    - condition: state
      entity_id: input_boolean.hallway_motion_lockout
      state: "off"

    - condition: state
      entity_id: timer.hallway_light_manual_override
      state: "idle"

    - if:
        - condition: state
          entity_id: light.hallway_ceiling
          state: "off"

      then:
        - condition: numeric_state
          entity_id: sensor.hallway_motion_illuminance
          below: 40

        - choose:
            - conditions:
                - condition: state
                  entity_id: input_select.light_mode
                  state: "night"
              sequence:
                - action: light.turn_on
                  target:
                    entity_id: light.hallway_ceiling
                  data:
                    brightness_pct: 10
                    transition: 1

          default:
            - action: light.turn_on
              target:
                entity_id: light.hallway_ceiling
              data:
                brightness_pct: 60
                transition: 1

        - action: input_boolean.turn_on
          target:
            entity_id: input_boolean.hallway_light_on_by_motion

- id: hallway_no_motion_starts_timer
  alias: Hallway - no motion starts the timer
  mode: restart

  triggers:
    - trigger: state
      entity_id: binary_sensor.hallway_motion
      to: "off"

  conditions:
    - condition: state
      entity_id: input_boolean.hallway_motion_lockout
      state: "off"

    - condition: state
      entity_id: light.hallway_ceiling
      state: "on"

    - condition: state
      entity_id: input_boolean.hallway_light_on_by_motion
      state: "on"

  actions:
    - action: timer.start
      target:
        entity_id: timer.hallway_light
      data:
        duration: "00:03:00"

- id: hallway_timer_turns_off_light
  alias: Hallway - the timer turns off the light
  mode: single

  triggers:
    - trigger: event
      event_type: timer.finished
      event_data:
        entity_id: timer.hallway_light

  conditions:
    - condition: state
      entity_id: input_boolean.hallway_motion_lockout
      state: "off"

    - condition: state
      entity_id: binary_sensor.hallway_motion
      state: "off"

    - condition: state
      entity_id: light.hallway_ceiling
      state: "on"

    - condition: state
      entity_id: input_boolean.hallway_light_on_by_motion
      state: "on"

  actions:
    - action: light.turn_off
      target:
        entity_id: light.hallway_ceiling
      data:
        transition: 1

    - action: input_boolean.turn_off
      target:
        entity_id: input_boolean.hallway_light_on_by_motion

Movie / Guests / Cleaning modes: don't turn on a bright light visible from the living room during Movie mode; Guests: a longer timer; Cleaning: often a local lockout. Adapt the automation's choose block to light_mode. A motion sensor that's unavailable isn't the same as no motion: don't turn the light off for that reason. After a manual turn-off, start timer.hallway_light_manual_override (a condition already checked in the first automation). Recognizing manual control depends on your hardware: check the Logbook; there's no single universal YAML for it. In your exercise, don't require detecting the source of a command if the device doesn't expose it: a separate manual-lockout button, or a button that runs through an HA script, is an acceptable alternative. light_mode is the last deliberately chosen logical mode: it isn't confirmation that every lamp actually adopted the scene.

Bathroom and kitchen: later, more carefully

Bathroom: presence on → cancel the timer, turn on if allowed; presence off → a 30-90 second timer; finished → confirm it's still off and check sensor availability; only turn off the light this automation owns. On unavailable: don't turn off automatically, fall back to a manual Plan B. On stuck-on: a diagnostic alert, not an aggressive shutoff. Test with the bathtub/shower screen, the fan, and steam: don't test electrical wiring near water.

Kitchen: a PIR at the entrance (ceiling-mounted, oriented) isn't the same as the counter zone. When cooking: an mmWave sensor at the counter, or a manual counter turn-on, a Cooking scene, and a long override. Don't turn off the counter light just because someone's standing still at the cutting board.

With Hue Motion, check the bridge-to-HA delay and the local path: don't assume "cloud polling" is a typical cause. Don't compare Zigbee to Wi-Fi with fixed millisecond figures: latency depends on the installation.

Testing motion-activated lighting

Technical dashboard: PIR battery, last motion, availability, the timer, the lockout, the last trigger time. Maximum lit time with a hung mmWave sensor: lean toward an alert rather than an aggressive shutoff in a bathroom.

Common mistakes

Hands-on exercise

Key takeaways

• A PIR detects motion, not certain human presence.
• mmWave needs calibration and can also generate false presence.
• Lux decides whether to turn a light on automatically, but shouldn't block holding an already-lit light on.
• Motion on cancels the shutoff, and motion off starts the countdown.
• A timer only turns a light off after confirming, again, that there's no motion.
• Automation should only turn off a light it turned on itself.
• A manual turn-on or turn-off takes priority over the sensor.
• Night mode is a better source of brightness than duplicated hours spread across many automations.
• Movie, Guests, and Cleaning modes have to affect how motion automation behaves.
• unknown and unavailable need a deliberately chosen fallback behavior.
• restore: true doesn't guarantee an action that was supposed to happen while HA was off actually runs.
• timer.cancel cancels the shutoff; timer.finish can trigger the completion event.
• You test one hallway first, and only then the bathroom and kitchen.

In Lesson 12 you'll add lighting based on the sun and schedules. Before moving on, the hallway should work reliably by hand, not just on paper in YAML.