async function main({ onActivate, onError, onReading, onDenied }) {
  const result = await navigator.permissions.query({
    name: 'ambient-light-sensor',
  })

  if (result.state === 'denied') {
    onDenied()
    return
  }

  const ambientLightSensor = new AmbientLightSensor({ frequency: 20 })
  
  ambientLightSensor.addEventListener('activate', onActivate)
  ambientLightSensor.addEventListener('error', onError)
  ambientLightSensor.addEventListener('reading', () => {
    const ISO = 100
    const C = 250

    const EV = Math.round(Math.log2((ambientLightSensor.illuminance * ISO) / C))

    onReading(EV)
  })

  ambientLightSensor.start()
}

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• AmbientLightSensor - Web APIs | MDN
• Ambient Light Sensor
• Sensors for the web - Chrome Developers¹
• Ambient Light Sensor | Can I use… Support tables for HTML5, CSS3, etc

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Footnotes

1. 주변광 센서 인터페이스가 포함된 일반 센서 API를 사용하는 방법을 설명 ↩