ESP32 - Motion Sensor - Relay
This tutorial instructs you how to use ESP32 with HC-SR501 motion sensor and relay. In detail, ESP32 automatically turns on relay if the motion is detected, and turn off relay if otherwise.
We can extend this tutorial to use the motion sensor to control a led strip, siren, light bulb, or actuator... by connnecting them to the relay.
Hardware Used In This Tutorial
|1||×||ESP-WROOM-32 Dev Module|
|1||×||Micro USB Cable|
|1||×||HC-SR501 Motion Sensor|
|1||×||Warning Light Bright Waterproof|
|1||×||12V Power Adapter|
|1||×||(Optional) 5V Power Adapter|
|1||×||(Optional) DC Power Jack|
|1||×||(Optional) ESP32 Screw Terminal Adapter|
Introduction to Relay and Motion Sensor
We have specific tutorials about relay and motion 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
|Detection Range Adjuster||Fully screw it in the clockwise direction.|
|Time Delay Adjuster||Fully screw it in the anti-clockwise direction.|
|Repeat Trigger Selector||Put jumper like the below 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
- Move your hand in front of 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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