The light can turn off in the middle of a book or work call even though you are still in the room. A motion sensor may report “motion detected” and later “clear”; if you sit still, its state can clear before you stand up. In Home Assistant, check the sensor state and the automation’s off delay separately.

This AI-assisted guide was checked against official Home Assistant documentation as of October 26, 2026. It does not claim that a physical sensor or room setup was tested. Results depend on the exact device, its integration, placement, and settings.

Key facts (2026)

• A Home Assistant binary sensor can represent motion or occupancy. Check the state of the actual entity; its name alone does not prove that it will stay occupied while someone sits still.
• A PIR sensor reacts to changes in infrared energy. Some mmWave sensors expose separate moving and still-target states, but this depends on the specific device and integration.
• A For at least duration delays an action only while the entity remains in the required state. It does not make a motion-only sensor detect a seated person.
• An unfinished duration is lost when Home Assistant restarts.

PIR and mmWave

Sensor type	Typical signal	Consider it for	Check before choosing
PIR, passive infrared	Changes in infrared energy caused by movement in its detection area	Turning a light on when people walk into a room	Whether its entity clears during quiet sitting and whether the field of view covers the seat
mmWave / radar presence	Some models can report still as well as moving targets	A desk, reading chair, or sofa where someone may stay still	Whether the exact device exposes still presence, its distance settings, and how it behaves in your room

These are broad technology differences, not a device ranking. Panasonic notes that PIR detection relies on changes in infrared energy and may struggle when there is no movement or temperature contrast. ESPHome's LD2410 documentation shows one specific implementation with moving-target and still-target states and distance thresholds. Those capabilities do not apply to every mmWave device.

Before buying anything, check the full model and the Home Assistant integration you plan to use. Brand-level support does not guarantee that every model exposes the same entities.

Set up the automation

Start with one room and one light. After adding the sensor using its manufacturer instructions, confirm that Home Assistant receives its state.

To turn on the light, use the automation editor: trigger when the sensor changes to occupied or motion detected; optionally add a low-light condition; then turn on the room light.

Create a separate off automation: when the sensor changes to clear and stays clear for a chosen duration, turn off the light. Start with a short duration only to verify the transition, then choose a period that fits the room. A delay cannot detect someone sitting still if the sensor has already reported the room as clear.

If presence returns before the duration ends, the state trigger's timer starts over. An unfinished For at least duration does not continue after a Home Assistant restart.

Check the room

1. Sit in the usual place and watch the sensor entity in History.
2. Note whether it becomes clear while you are still sitting.
3. Leave the room and record how long it takes the entity to clear and the light automation to run.
4. Check whether the sensor reports presence from an adjacent area. Adjust its coverage using the device documentation and retest.
5. Review the automation trace to see which trigger ran, whether its conditions passed, and which action followed.
6. Repeat after choosing settings, including normal use of any wall switch.

Change one setting at a time. If the entity turns off while you sit, investigate the sensor and its placement. If it remains occupied but the light still turns off, inspect the automation trigger and conditions.

Frequently asked questions

Is PIR suitable for a living room?

It can be suitable when people move through the room. For long periods of sitting, check whether the exact sensor keeps reporting occupancy in that situation.

Is mmWave always better?

No. Some mmWave sensors can report subtle or still targets, but results depend on the device, setup, and room. Check the coverage and state history before changing hardware.

Will the off timer continue after a Home Assistant restart?

Not if it is an unfinished For at least duration. Home Assistant resets that wait on restart.

Sources: Home Assistant binary sensors, automation triggers, automation troubleshooting, ESPHome LD2410, Panasonic PIR sensor FAQ.