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Motion light

Turns the hall light on when someone walks by after sunset. Late at night it is dimmed, so it does not wake anyone. A few minutes after the motion stops, it turns off again.

You need a motion sensor and a dimmable light.

apps/NightMotionLight.php
<?php


declare(strict_types=1);


namespace App;


use Stewart\Contracts\App;
use Stewart\Contracts\Automation;
use Stewart\Contracts\HaContext;
use Stewart\Contracts\Service\ServiceTarget;
use Stewart\Contracts\Sun\SunCalendar;
use Stewart\Contracts\Time\Clock;
use Stewart\Contracts\Time\Duration;


#[Automation(id: 'night-motion-light')]
final readonly class NightMotionLight implements App
{
    public function __construct(
        private HaContext $ha,
        private SunCalendar $sun,
        private Clock $clock,
        private string $motionSensor = 'binary_sensor.hall_motion',
        private string $light = 'light.hall',
        private int $offAfterMinutes = 3,
        private int $dayBrightness = 100,
        private int $nightBrightness = 10,
    ) {}


    public function initialize(): void
    {
        $this->ha->watchStateChanges($this->motionSensor)
            ->whenChangedTo('on')
            ->filter(fn(): bool => !$this->sun->isSunUp())
            ->subscribe(function (): void {
                $brightness = $this->clock->isWithin('23:00', '06:00') ? $this->nightBrightness : $this->dayBrightness;
                $this->ha->callService('light', 'turn_on', ['brightness_pct' => $brightness], ServiceTarget::forEntities($this->light));
            });


        $this->ha->watchStateChanges($this->motionSensor)
            ->whenChangedTo('off', for: Duration::minutes($this->offAfterMinutes))
            ->subscribe(function (): void {
                if ($this->ha->getState($this->light)?->state === 'on') {
                    $this->ha->callService('light', 'turn_off', target: ServiceTarget::forEntities($this->light));
                }
            });
    }


    public function dispose(): void {}
}
apps:
  night-motion-light:
    options:
      motionSensor: binary_sensor.hall_motion
      light: light.hall
      offAfterMinutes: 3
      nightBrightness: 10

How it works

Section titled “How it works”
  • filter(fn () => !$this->sun->isSunUp()) lets motion through only while the sun is down.
  • Clock::isWithin('23:00', '06:00') picks the brightness. The window may cross midnight.
  • whenChangedTo('off', for: …) turns the light off only once the sensor has reported no motion for the whole time. New motion starts the wait again.
  • The light is only turned off if it is still on, so a light someone already switched off is left alone.

Test

Section titled “Test”
tests/NightMotionLightTest.php
<?php


declare(strict_types=1);


namespace App\Tests;


use App\NightMotionLight;
use DateTimeImmutable;
use PHPUnit\Framework\TestCase;
use Stewart\Contracts\Time\Duration;
use Stewart\Testing\App\AppHarness;


final class NightMotionLightTest extends TestCase
{
    public function testLateAtNightTheLightIsDim(): void
    {
        $harness = $this->startAt('2026-01-01 23:30 UTC');


        $harness->ha->pushState('binary_sensor.hall_motion', 'on');


        self::assertSame(['brightness_pct' => 10], $harness->ha->getLastCall()->data);
    }


    public function testInTheEveningTheLightIsBright(): void
    {
        $harness = $this->startAt('2026-01-01 19:00 UTC');


        $harness->ha->pushState('binary_sensor.hall_motion', 'on');


        self::assertSame(['brightness_pct' => 100], $harness->ha->getLastCall()->data);
    }


    public function testDuringTheDayNothingHappens(): void
    {
        $harness = $this->startAt('2026-01-01 12:00 UTC');


        $harness->ha->pushState('binary_sensor.hall_motion', 'on');


        self::assertTrue($harness->ha->calls->isEmpty());
    }


    public function testTheLightTurnsOffAfterTheMotionStops(): void
    {
        $harness = $this->startAt('2026-01-01 19:00 UTC');
        $harness->ha->pushState('binary_sensor.hall_motion', 'on');
        $harness->ha->pushState('light.hall', 'on');
        $harness->ha->pushState('binary_sensor.hall_motion', 'off');


        $harness->advanceTime(Duration::minutes(3));


        self::assertSame('light.turn_off', $harness->ha->getLastCall()->getServiceName());
    }


    private function startAt(string $moment): AppHarness
    {
        $harness = new AppHarness(new DateTimeImmutable($moment));
        $harness->ha->seedState('binary_sensor.hall_motion', 'off');
        $harness->ha->seedState('light.hall', 'off');
        $harness->startApp(NightMotionLight::class);


        return $harness;
    }
}

Make it yours

Section titled “Make it yours”
  • Skip the dimming when someone is watching TV: add a check of media_player.living_room in the handler.
  • Leave a light alone after someone switched it by hand: see Your own changes.
  • Several rooms: an app runs once, so copy the class under another name and ID, or watch an area filter and turn on the lights of the area where the motion was.