O Level Exam : Practical Question
📝 HTML
🎨 CSS
⚡ Java Script
const int photodiodePin = A0; const int ledPin = 13; int sensorValue = 0; int threshold = 50; // Adjust this value based on your ambient light unsigned long turnOnTime = 0; unsigned long turnOffTime = 0; void setup() { pinMode(ledPin, OUTPUT); Serial.begin(9600); } void loop() { sensorValue = analogRead(photodiodePin); Serial.println(sensorValue); if (sensorValue < threshold) { if (digitalRead(ledPin) == LOW) { turnOnTime = millis(); Serial.print("LED turned on at: "); Serial.println(turnOnTime); } digitalWrite(ledPin, HIGH); // Turn on the LED } else { if (digitalRead(ledPin) == HIGH) { turnOffTime = millis(); Serial.print("LED turned off at: "); Serial.println(turnOffTime); } digitalWrite(ledPin, LOW); // Turn off the LED } delay(100); // Delay for stability }
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🖥 Output: