SR04M-2 Waterproof Ultrasonic Distance Sensor Module 5V 25-450cm
The SR04M-2 Waterproof Ultrasonic Distance Sensor Module is designed for non-contact distance measurement in environments where a conventional open ultrasonic transducer may be exposed to moisture, dust, or outdoor conditions. The system separates the ultrasonic sensing probe from the electronic control board, allowing the probe to be positioned at the measurement point while the PCB remains protected in a suitable enclosure.
The module determines distance by transmitting an ultrasonic pulse and measuring the time required for the reflected sound wave to return from the target. A single enclosed ultrasonic transducer is used for both transmitting and receiving. The control board processes the returned signal and provides a pulse-width output that can be read by a microcontroller to calculate the distance.
The SR04M-2 can be integrated into Arduino and other microcontroller-based systems using a trigger-and-echo style interface similar to common ultrasonic ranging modules. Its remote probe configuration makes it particularly useful where the sensing point needs to be separated from the main electronics. The control board itself should remain protected from water and environmental exposure even when the external ultrasonic probe is installed in a wet location.
Features
- Non-contact ultrasonic distance measurement.
- Separate sealed ultrasonic sensing probe.
- Single transducer for ultrasonic transmission and reception.
- Remote probe design keeps control electronics away from the sensing point.
- Trigger/Echo style digital interface in standard operating mode.
- RX pin functions as Trigger input.
- TX pin functions as Echo output.
- Compatible with Arduino-style ultrasonic measurement code.
- Suitable for outdoor and moisture-exposed sensing applications when the PCB is protected.
- Long probe cable for flexible installation.
- Compact control PCB.
- Mounting holes on the control board.
Ultrasonic Sensor Module Parts
Specifications
| Specification | Value |
|---|---|
| Model: | SR04M-2 |
| Sensor Type: | Waterproof-Probe Ultrasonic Distance Sensor |
| Measurement Method: | Non-contact ultrasonic time-of-flight |
| Operating Voltage: | 5V DC |
| Quiescent Current: | 5mA |
| Operating Current: | 30mA |
| Ultrasonic Frequency: | 40kHz |
| Measuring Range: | 25cm to 450cm |
| Blind Zone / Minimum Distance: | 25cm |
| Maximum Measuring Distance: | 450cm / 4.5m |
| Resolution: | 0.5cm |
| Detection Angle: | <50° |
| Trigger Input: | HIGH pulse of ≥10µs |
| Default Interface: | Trigger / Echo pulse-width |
| RX Pin Function: | TRIG input |
| TX Pin Function: | ECHO output |
| Working Temperature: | -10°C to +70°C |
| Storage Temperature: | -20°C to +80°C |
| Probe Cable Length: | 2.25m |
| PCB Dimensions: | 41 × 28.4 ×20 mm |
| Probe Configuration: | Single ultrasonic transducer used for transmit and receive |
| Waterproof Part: | Ultrasonic probe only |
| Control PCB Waterproof: | No |
| RST Pin: | Factory/programming use – normally unused |
| SWIM Pin: | Factory/programming use – normally unused |
Note: The waterproof protection applies to the ultrasonic probe only. The electronic control PCB is not waterproof and must be installed inside a protected enclosure. The sensor is intended to measure distance through air and can be used to measure the distance to a water surface; the complete module should not be submerged.
Pinout
| Marking on Your PCB | Normal Function | Connection |
|---|---|---|
| 5V | Power | +5V DC |
| RX | Trigger Input | MCU Digital Output |
| TX | Echo Output | MCU Digital Input |
| GND | Ground | GND |
| RST | Programming / Factory Pad | Leave Unconnected |
| SWIM | STM8 Programming / Factory Pad | Leave Unconnected |
Ultrasonic Module with Arduino Connection Diagram
The Following connections are made between Arduino UNO and the Sensor:
Applications
- Water Tank Level Monitoring.
- Liquid Surface Distance Measurement.
- Outdoor Distance Measurement.
- Robot Obstacle Detection.
- Parking Assistance Systems.
- Industrial Automation.
- Security and Presence Detection.
- Smart Agriculture Systems.
- Traffic and Access Monitoring.
Package Contents
- 1× SR04M-2 Ultrasonic Control Board
- 1× Waterproof Ultrasonic Probe with 2.25m Cable
