This example is like a dark activated alarm using an LDR and a LED, in this case when the value read in drops below a certain level the LED will light. In the real world you could make a dark activated night light or alarm.
Its a fairly basic circuit, I connected the LED to D8, no real reason. LDR still connects to A0
Schematic and Layout
Code
[codesyntax lang=”cpp”]
int sensorPin = A0; // select the input pin for the ldr int ledPin = 8; // select the pin for the LED int sensorValue = 0; // variable to store the value coming from the sensor void setup() { pinMode(ledPin, OUTPUT); } void loop() { sensorValue = analogRead(sensorPin); if(sensorValue <= 400) { digitalWrite(ledPin, HIGH); delay(500); } else { digitalWrite(ledPin, LOW); } }
[/codesyntax]