Arduino Nano - Light Sensor LED
This tutorial instructs you how to use Arduino Nano and light sensor to trigger LED. In detail:
- Arduino Nano turns on the LED if the analog value of the light sensor is lower than a certain threshold (when dark)
- Arduino Nano turns off the LED if the analog value of the light sensor is greater than a certain threshold (when light)
The light sensor is also known as photoresistor, light-dependent resistor, photocell, LDR. Arduino Nano measures the light level of ambience via a light sensor, if it is dark, Arduino Nano turns on LED and vice versa.
Hardware Preparation
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
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Overview of LED and Light Sensor
If you are unfamiliar with LED and light sensor (pinout, functionality, programming ...), please refer to the following tutorials:
Wiring Diagram
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Arduino Nano Code
/*
* This Arduino Nano code was developed by newbiely.com
*
* This Arduino Nano code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-nano/arduino-nano-light-sensor-led
*/
const int LIGHT_SENSOR_PIN = A0; // The Arduino Nano pin connected to light sensor's pin
const int LED_PIN = 2; // The Arduino Nano pin connected to LED's pin
const int ANALOG_THRESHOLD = 500;
int analog_value;
void setup() {
pinMode(LED_PIN, OUTPUT); // set arduino pin to output mode
}
void loop() {
analog_value = analogRead(LIGHT_SENSOR_PIN); // read the input on analog pin
if(analog_value < ANALOG_THRESHOLD)
digitalWrite(LED_PIN, HIGH); // turn on LED
else
digitalWrite(LED_PIN, LOW); // turn off LED
}
Detailed Instructions
- Connect your Arduino Nano to your computer using a USB cable.
- Launch the Arduino IDE, select the appropriate board and port.
- Copy the code above and open it in the Arduino IDE.
- Click the Upload button in the Arduino IDE to compile and upload the code to the Arduino Nano.
- Emit light source towards the sensor
- Check out the LED's state
Code Explanation
Check out the line-by-line explanation contained in the comments of the source code!