ESP32 - Light Sensor Triggers LED

In this tutorial, We are going to learn how to:

Hardware Required

1×ESP-WROOM-32 Dev Module
1×Micro USB Cable
1×Light Sensor
1×LED
1×220 ohm resistor
1×10 kΩ resistor
1×Breadboard
n×Jumper Wires
Please note: These are affiliate links. If you buy the components through these links, We may get a commission at no extra cost to you. We appreciate it.

About LED and Light Sensor

If you do not have knowledge of LED and light sensor (pinout, how they work, how to connect them to ESP32, how to program for them...), learn about them in the following tutorials:

Wiring Diagram

ESP32 Light Sensor LED Wiring Diagram

Image is developed using Fritzing. Click to enlarge image

ESP32 Code

/* * Created by esp32io.com * * This example code is in the public domain * * Tutorial page: https://esp32io.com/tutorials/esp32-light-sensor-triggers-led */ // constants won't change const int LIGHT_SENSOR_PIN = A0; // ESP32 pin connected to light sensor's pin const int LED_PIN = 3; // ESP32 pin connected to LED's pin const int ANALOG_THRESHOLD = 500; // variables will change: int analogValue; void setup() { pinMode(LED_PIN, OUTPUT); // set ESP32 pin to output mode } void loop() { analogValue = analogRead(LIGHT_SENSOR_PIN); // read the input on analog pin if(analogValue < ANALOG_THRESHOLD) digitalWrite(LED_PIN, HIGH); // turn on LED else digitalWrite(LED_PIN, LOW); // turn off LED }

Quick Steps

  • If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE
  • Connect the ESP32 board to your PC via a micro USB cable
  • Open Arduino IDE, select the right ESP32 board and COM port
  • Copy the above code and paste it to Arduino IDE
  • Click Upload button on Arduino IDE to compile and upload code to ESP32 board
  • Arduino IDE Upload Code
  • Radiates light to sensor
  • See the change of LED's state

Code Explanation

Read the line-by-line explanation in comment lines of source code!

Video Tutorial

We are considering to make the video tutorials. If you think the video tutorials are essential, please subscribe to our YouTube channel to give us motivation for making the videos.

※ NOTE THAT:

Note that this tutorial is incomplete. We will post on our Facebook Page when the tutorial is complete. Like it to get updated.

※ NOTICES

  • We are AVAILABLE for HIRE. See how to hire us to do your project
  • If this tutorial is useful for you, please support us to make more tutorials.
  • We spent a lot of time and effort to create the content for this tutorial, please respect our work! Please do not copy the content to share on other websites. Howerver, please feel free to share the link of this tutorial anywhere