Arduino - Water Sensor Pump

In this tutorial, we will learn how to use an Arduino to activate a pump for draining water when it is detected by a water sensor. In other words, we will be discovering how to create an automatic drainage system using an Arduino, a water sensor, and a pump

Hardware Required

1	×	Arduino UNO or Genuino UNO
1	×	USB 2.0 cable type A/B (for USB-A PC)
1	×	USB 2.0 cable type C/B (for USB-C PC)
1	×	Water level sensor
1	×	Relay
1	×	12V Pump
1	×	Vinyl Tube
1	×	12V Power Adapter
1	×	DC Power Jack
1	×	Jumper Wires
1	×	(Recommended) Screw Terminal Block Shield for Arduino Uno
1	×	(Recommended) Breadboard Shield For Arduino Uno
1	×	(Recommended) Enclosure For Arduino Uno

Or you can buy the following sensor kits:

1	×	DIYables Sensor Kit (30 sensors/displays)
1	×	DIYables Sensor Kit (18 sensors/displays)

Disclosure: Some links in this section are Amazon affiliate links. If you make a purchase through these links, we may earn a commission at no extra cost to you.
Additionally, some links direct to products from our own brand, DIYables.

About Water Sensor and Pump

If you do not know about water sensor and pump (pinout, how it works, how to program ...), learn about them in the following tutorials:

Arduino - Water Sensor tutorial
Arduino - controls pump tutorial

How the Automatic Drainage System Works

Arduino periodically reads the value from the water sensor, then:

If the value is greater than a pre-defined threshold, Arduino turns on the relay to activate the pump.
Otherwise, Arduino turns off the pump.

Wiring Diagram

This image is created using Fritzing. Click to enlarge image

Arduino Code

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-water-sensor-pump */ #define RELAY_PIN A0 // The Arduino pin that connects to the relay to control the pump #define POWER_PIN 7 // The Arduino pin that provides the power to the water sensor #define SIGNAL_PIN A5 // The Arduino pin that reads the value from the water sensor #define THRESHOLD 300 // The threshold for water detectiion void setup() { Serial.begin(9600); pinMode(RELAY_PIN, OUTPUT); // configure D2 pin as an OUTPUT pinMode(POWER_PIN, OUTPUT); // configure D7 pin as an OUTPUT digitalWrite(POWER_PIN, LOW); // turn the water sensor OFF digitalWrite(RELAY_PIN, LOW); // turn the pump OFF } void loop() { digitalWrite(POWER_PIN, HIGH); // turn the water sensor's power ON delay(10); // wait 10 milliseconds int value = analogRead(SIGNAL_PIN); // read the analog value from sensor digitalWrite(POWER_PIN, LOW); // turn the water sensor's power OFF if (value > THRESHOLD) { Serial.print("The water is detected"); digitalWrite(RELAY_PIN, HIGH); // turn the pump ON } else { digitalWrite(RELAY_PIN, LOW); // turn the pump OFF } delay(1000); // pause for 1 sec to avoid reading sensors frequently to prolong the sensor lifetime }

Quick Steps

Connect Arduino to PC via USB cable
Open Arduino IDE, select the right board and port
Copy the above code and open with Arduino IDE
Click Upload button on Arduino IDE to upload code to Arduino

Embed the water sensor into the water
See the pump's state

Code Explanation

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

Video Tutorial

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