Waterproof Ultrasonic Module

🔹 Waterproof Ultrasonic Sensor Module – JSN-SR04T / AJ-SR04M

This is a waterproof ultrasonic distance measuring module, available in two common variants: JSN-SR04T and AJ-SR04M. Designed for outdoor and industrial applications, it features an IP67 waterproof transducer that allows reliable distance measurement in wet, dusty, or harsh environments. Ideal for tank level monitoring, robotics obstacle avoidance, parking sensors, and outdoor automation projects.

✅ Specifications (Common to both variants):

• Operating Voltage: 3.3V – 5V DC

• Quiescent Current: < 5mA

• Working Current: 15mA – 30mA (during measurement)

• Measuring Range: 25cm – 450cm (JSN-SR04T), 20cm – 600cm (AJ-SR04M)

• Resolution: 0.5cm – 1cm

• Measuring Angle: 45° – 75° (beam pattern)

• Ultrasonic Frequency: 40kHz

• Interface: 4-pin (VCC, Trig, Echo, GND) – compatible with HC-SR04 code

• Transducer Material: Epoxy resin encapsulated, IP67 waterproof

• Cable Length: 2.5m – 4m (typical, varies by model)

• Operating Temperature: -15°C to +70°C

• Dimensions (Control Board): ~35mm x 20mm x 15mm

• Dimensions (Sensor Head): ~18mm diameter x 18mm length

✅ JSN-SR04T Specifics:

• Range: 25cm to 450cm

• Accuracy: ±1cm (typical)

• Connection: Separate control board with cable to waterproof sensor head

• Special Features: Built-in temperature compensation

✅ AJ-SR04M Specifics:

• Range: 20cm to 600cm

• Accuracy: ±0.5cm (typical)

• Connection: Integrated control circuit in sensor head housing (single unit)

• Special Features: Auto gain control, higher sensitivity

📦 Applications:
✔️ Water tank level monitoring (rivers, wells, reservoirs)
✔️ Outdoor robotics obstacle avoidance
✔️ Parking sensor systems (car, garage, industrial vehicles)
✔️ Agricultural automation (sprayer boom height control)
✔️ Industrial distance measurement
✔️ Marine and nautical applications
✔️ Weather-exposed automation projects
✔️ Arduino, ESP32, Raspberry Pi outdoor projects
✔️ Flood detection and prevention systems

📦 Features:
✔️ Fully waterproof transducer (IP67 rated)
✔️ Direct HC-SR04 code compatibility (no library changes needed)
✔️ Low power consumption for battery operation
✔️ Long cable length for remote sensing
✔️ Stable performance in varying temperatures
✔️ Easy mounting with threaded sensor head

⚠️ Important Notes:

• Minimum distance. Both modules have a blind zone of approximately 20-25cm; objects closer than this may not be detected accurately.

• Echo signal. Echo output is 5V tolerant, safe for 5V microcontrollers.

• Soft objects. Sound-absorbing materials (cloth, foam) may reduce effective range.

• Power supply. Ensure stable power; voltage drops during measurement can affect accuracy.

• Trigger pulse. Requires a 10µs TTL pulse to trigger measurement.