ESP32 - Light Sensor Triggers Relay
This tutorial instructs you how to use ESP32, light sensor and relay to do a project that:
- Turns relay on if the analog value measured from light sensor's is below a threshold,
- Turns relay off if the analog value measured from light sensor's is above a threshold,
We can extend this tutorial to automatically turn on a led strip or light bulb when it is dark.
Hardware Used In This Tutorial
One of the following breadboard:
|1||×||Full-sized 830-Point Breadboard|
|1||×||Half-sized 400-point Breadboard|
|1||×||Mini-sized 170-point Breadboard|
|1||×||All-sized Breadboard Kit|
Introduction to Relay and Light Sensor
We have specific tutorials about relay and light sensor. Each tutorial contains detailed information and step-by-step instructions about hardware pinout, working principle, wiring connection to ESP32, ESP32 code... Learn more about them at the following links:
This image is created using Fritzing. Click to enlarge image
- If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
- Do the wiring as above image.
- Connect the ESP32 board to your PC via a micro USB cable
- Open Arduino IDE on your PC.
- Select the right ESP32 board (e.g. ESP32 Dev Module) and COM port.
- Copy the above code and paste it to Arduino IDE.
- Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
- Radiates light to sensor
- See the change of relay's state
Line-by-line Code Explanation
The above ESP32 code contains line-by-line explanation. Please read the comments in the code!
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