Easy Basics Project 008b Water level sensor and LED

of Acoptex.com in UNO

Basics: Project 008b

Project name: Water level sensor and LED

Attachments: program 1 or program 2

In this project, you needed these parts :

1.Aruduino Uno R3 (you can also use the other version of Arduino)

2.Water level sensor module

3.Arduino IDE ( you can download it from here  )

4.Jumper cables

5. LED 1 pc (red)

6. Resistor 1 pc 220 Om

7. Breadboard half size (optional)

Understanding the water level sensor module

Water level sensor module is designed for water detection, which can be widely used in sensing the rainfall, water level, even the liquate leakage. The brick is mainly comprised of three parts: An Electronic brick connector, a 1 MΩ resistor, and several lines of bare conducting wires. This sensor works by having a series of exposed traces connected to ground and interlaced between the grounded traces are the sens traces. The sensor traces have a weak pull-up resistor of 1 MΩ. The resistor will pull the sensor trace value high until a drop of water shorts the sensor trace to the grounded trace. Believe it or not this circuit will work with the digital I/O pins of your Arduino or you can use it with the analog pins to detect the amount of water induced contact between the grounded andsensor traces. This item can judge the water level through with a series of exposedparallel wires stitch to measure the water droplet/water size. This item can easily change the water size to analog signal, and outputanalog value can directly be used in the program function, then to achievethe function of water level alarm.This item have low power consumption, and high sensitivity, which are the biggest characteristics of this module.

You can see datasheet here.


  • Working voltage: 5V
  • Working Current: <20ma3
  • Interface: Analog
  • Width of detection: 40mm×16mm
  • Working Temperature: 10℃~30℃
  • Weight: 3g
  • Size: 65mm×20mm×8mm
  • Arduino compatible interface
  • Low power consumption
  • High sensitivity
  • Output voltage signal: 0~4.2V

Signals and connections of water level sensor, LED

"S" stand for signal input (analog)

"+" stand for power supply (+5V)

"-" stand for GND

If you do not have marking on the back of water level sensor module - not a problem. You can print this marking

attach and cover it with silicon to the back of sensor. Just make sure that silicon is dry andbe careful do not use silicon on other side as it will damage the sensor.

Connect the long leg of the LED (the positive leg, called the anode) to the other end of the resistor. Connect the short leg of the LED (the negative leg, called the cathode) to the GND. Resistor connected for long leg.


The following picture shows the needed connections with the Arduino Uno 

Watch video here: https://youtu.be/35RT_X9m8XE

Step by Step instruction

  1. Plug your Adruino Uno board into your PC and select the correct board and com port
  2. Open up serial monitor and set your baud to 9600 baud
  3. Do calibration. Take a paper and write down readings of the sensor and the water level in mm or inch  (for example, 0mm -0, 5mm - 223, 10mm - 251, 20mm - 294, 30mm - 314, 40mm - 333)
  4. Verify and upload the the sketch to your Adruino Uno


  • No libraries needed for this project


Program 1 attached here.

Program 2 attached here.

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Published at 08-05-2017
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