Attributes

Brand	-
Category	Robotics / STEM Teaching Tools / Sensors
Origin	-
Model Number	M03 / M04
Detection Type	Non-Contact Liquid Level
Output Signal	Digital Switch (High/Low)
Operating Voltage	3.3V - 5V DC
PCB Color	Green
Interface Type	3-Pin Header
Compatibility	Arduino, ESP32, STM32, Raspberry Pi
Response Time	< 1 Second
Mounting Style	External Tank Mounting
Application	Water Tanks, Sump Pumps, Aquariums

6 reviews

Anonymous

Mar 30, 2026

Rating: 5/5

Great for IoT prototypes

Used this in a smart home water leak detector prototype. The digital output makes coding very straightforward. No issues after two weeks of continuous testing.

Anonymous

Mar 19, 2026

Rating: 4/5

Good value, sensitive adjustment needed

Works well for detecting water levels in my rain barrel. Had to tweak the sensitivity potentiometer slightly to avoid false triggers from condensation, but once set, it's reliable.

Anonymous

Mar 17, 2026

Rating: 5/5

Reliable and compact

Small form factor makes it easy to hide behind plastic tanks. The green PCB is clear and the soldering points are well-defined. Highly recommend for hobbyists.

Anonymous

Mar 17, 2026

Rating: 5/5

Beginner friendly

As someone new to sensors, this was very easy to set up. Plenty of tutorials online for the M03/M04 series. Worked on the first try with my ESP8266.

Anonymous

Mar 05, 2026

Rating: 4/5

Does the job

Solid sensor for the price. It detects water through thin plastic walls perfectly. Just make sure your power supply is stable to prevent fluctuating readings.

Anonymous

Mar 01, 2026

Rating: 5/5

Perfect for my aquarium project

This sensor works exactly as described. The non-contact feature is great because I don't have to worry about corrosion inside the tank. Easy to integrate with my Arduino setup.

5 FAQ

Q: Does it work with saltwater?

A: Yes, it can detect saltwater. However, due to the higher conductivity of saltwater, you may need to adjust the sensitivity potentiometer to prevent over-sensitivity.

Q: Can this sensor detect water through a 5mm thick plastic container?

A: Yes, the M03/M04 module is designed for non-contact detection and can typically sense liquid through plastic containers up to 10mm thick, depending on the material density.

Q: What is the current consumption of this sensor?

A: The module typically consumes around 5mA to 10mA when active, making it suitable for battery-powered projects with sleep modes.

Q: Is this module waterproof itself?

A: The sensing area on the back is coated for protection, but the electronic components on the front (green side) are not waterproof. Please ensure only the sensing side contacts the environment or mount it externally.

Q: Are there any libraries available for Arduino?

A: Since this is a digital switch output, you do not need a specific library. You can simply read the pin state using the standard digitalRead() function in Arduino IDE.

Explore your interests

STC32G12K128 STC8H8K64U Microcontroller Small System Core Board Development Board Emulator

$16.50

Youxin Electronics_STM32H743IIT6 Core Board System Board Learning Board STM32 Development Board

$118.00

Arduino DUE Development Board 32-bit ARM Controller A000062 Italian Official Original Import with Cable

$299.00

Ultrasonic Sensor HC-SR04 Ultrasonic Distance Measuring Module Bracket US015-025-026-100

$3.16

Serial SHT20 Chip Temperature and Humidity Sensor Test, SHT30 Chip Measurement and Monitoring Module by Viter Intelligence

$11.00

High-Speed Yabo Smart Raspberry Pi 4B Motherboard Development Board Accessories RaspberryPi 2G/4G/8G RAM Py

$494.30

Magnetic Circular Counting Chips, Two-Sided Flip Coins for Elementary Math, Kindergarten Early Education, Ten-Frame Matrix, Addition/Subtraction within 10 & 20, Teaching Tools

$11.90

3-Wire/4-Wire Flame Sensor Module, Fire Source Detection with IR Receiver, Flame Detection and Alarm

$1.08

SANSI White Label Class A Glass Graduated Cylinder C18 Micro-Precision Demulsification Cylinder with Scale Measurement Includes Certificate Ground Joint Stopper Hexagonal Bottom Borosilicate Glass Lab Equipment

$3.68

EV2400 Battery Unlock Fuel Gauge Programmer MSP430 HPA500 Evaluation Module Interface Board SMBus

$323.00

Cube Three-View Teaching Aid with Grid - 3D Geometry Observation Tool for Grades 4-5 Math (2cm Cubic Blocks Set)

$15.10

OrangePi Orange Pi Zero3 Zero 3 Development Board Allwinner H618 Orange Pi

$228.00

Digital 38KHz Infrared Receiver Transmitter Head Sensor Module Electronic Building Blocks Robot Infrared Communication Remote Control

$2.29

12V Stable Version Light-Control Switch No-Light Sensing with Extension Cable Photoresistor Plus Relay Module

$49.20

STM32 Smart Car 51 Microcontroller Arduino Obstacle Avoidance Chassis Kit Mecanum Wheel Robot Car

$40.80

Tech Small Production Small Invention DIY Piano Electronic Keyboard Real Playable Science Small Handmade DIY Materials

$33.00

HX711 Pressure Sensor Module Electronic Scale Bracket Weighing DIY Scale Pan Tray Set 5/10/40kg200

$3.28

Transparent 3D Geometric Model Perspective Decomposition Graphic Teaching Aid, Complete Set for Elementary Grades 1-6 Math

$6.80

Thin Film Pressure Sensor Display, USB Rechargeable Flexible Resistive Pressure Digital Display Module, Wide Range Wireless

$20.00

E18-D80NK Infrared Photoelectric Switch Diffuse Reflection Obstacle Avoidance Sensor Module 3-80CM

$12.60

LAN8720 Module Network Module Ethernet Transceiver RMII Interface Development Board Xinwei Electronics

$7.85

STC15W408AS Core Board Minimum System Board 51 Microcontroller Development Board TTSOP20 Learning Board

$18.47

New Version MEGA2560 R3 Development Board, Improved MEGA2560 R3 with Sensor Expansion Board

$13.68

Gradient Visual Illusion Kit: Electric Rotating Assembly Toy for Maker DIY, Paintable Handmade Model

$8.72

51/AVR Microcontroller Core Development Board STC89C52RC/51MCU Experiment Board/ATMEGA32 Learning Board

$37.90

[Trial Pack] Xianlang Complete Cat Treat Sticks Meal Packs Main Course Cans Freeze-Dried Cat Food Sample Snacks Gift Set

$15.00

5A Range Current Transformer Module Voltage Sensor Single-Phase AC Active Output Current Transmitter

$5.06

Foldable Clothes Drying Rack Floor Standing Home Balcony Bedroom Hanging Clothes Quilt Drying Artifact Outdoor Cooling Rod Indoor Drying Rack

$47.10

Metal Detector Module Non-Contact Metal Induction Sensor Detection Module Metal Detector

$8.70

RV1103 Miniature Linux Development Board: RISC-V Vision and AI with Ethernet Port

$53.10

For Arduino Development Board R3 Mainboard Microcontroller Module Kit Programming Learning Board Sensor Suite

$78.00

Xuefen Geometry Stamping and Tracing Set for Grades 1-2, 3D and 2D Ink Pads, Math Learning Tools, Cube and Cuboid Models

$4.51

Rubber Tire Toy 4WD Smart Car Wheels Car Model Robot Accessories (Suitable for 2mm Axle)

$0.50

E18-D80NK Infrared Obstacle Avoidance Sensor Proximity Switch Smart Robot Car 10-80cm

$6.30

Digital 38KHz Infrared Receiver/Transmitter Head Sensor Module for Electronic Building Blocks Robots, Infrared Communication Remote Control

$2.80

51 MCU Minimum System STC89C52 DIP40 Through-Hole Smart Car Main Control Board Learning Experiment

$19.80

Outdoor Adventure Kids' Insect Observation Box with Magnifying Glass, Boys & Girls Toy for Exploration, Butterfly Catching and Fish Scooping Tools

$7.80

MPU-9255 9-Axis Attitude 3-Axis Electronic Compass Accelerometer Gyroscope Magnetic Field Sensor Module

$13.42

Freeze-Dried Chicken Treats for Dogs: Nutritious Weight-Gain Breast Meat Chunks for Puppies – Teeth Cleaning, Grain Mixing, Universal Use

$3.90

Ningbo Keli SQB Cantilever Beam Weighing Module Sensor 100kg 500kg 1t 2t 3 Ton Small Floor Scale Inductor

$48.00