ESP32 - Soil Moisture Sensor Pump
In this tutorial, We are going to learn how to use the ESP32 to control the pump according to the value read from the capacitive soil moisture sensor.
Hardware Used In This Tutorial
Or you can buy the following sensor kit:
1 | × | DIYables Sensor Kit 30 types, 69 units |
Introduction to soil moisture sensor and Pump
If you do not know about pump and soil moisture sensor (pinout, how it works, how to program ...), learn about them in the following tutorials:
- ESP32 - Soil Moisture Sensor tutorial
- ESP32 - Controls Pump tutorial
How It Works
ESP32 periodically reads the value from the capacitive soil moisture sensor. Based on the soil moisture value, it will take the following actions:
- If the soil moisture value is below a threshold, ESP32 automatically activates a relay to turn a pump on.
- Otherwise, ESP32 automatically deactivates a relay to turn a pump off.
Wiring Diagram

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ESP32 Code
Quick Instructions
- If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
- Do calibration to determine the wet-dry THRESHOLD, see ESP32 - Calibrates Soil Moisture Sensor
- Update the calibrated value to THRESHOLD in the code
- Open Serial Monitor on Arduino IDE
- Upload the code to ESP32
- Check out the result on Serial Monitor.
Code Explanation
Read the line-by-line explanation in the comment lines of the source code!
Video Tutorial
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