How to Use JSN-SR04T Ultrasonic Sensor: Examples, Pinouts, and Specs

The JSN-SR04T is an ultrasonic distance sensor that uses sound waves to measure the distance to an object. It features a waterproof design, making it suitable for outdoor applications. This sensor is capable of providing accurate distance measurements in a range of 20 cm to 6 meters. Its robust design and reliable performance make it ideal for applications such as obstacle detection, liquid level measurement, and outdoor robotics.

• Obstacle detection in robotics
• Liquid level monitoring in tanks
• Parking assistance systems
• Outdoor distance measurement
• Smart irrigation systems

The JSN-SR04T is designed to operate in a variety of environments, offering reliable performance even in challenging conditions. Below are its key technical details:

The JSN-SR04T has a 4-pin interface for easy integration into circuits. Below is the pinout description:

1. Power the Sensor: Connect the VCC pin to a 5V DC power source and the GND pin to ground.
2. Trigger the Sensor: Send a 10 µs HIGH pulse to the Trig pin to initiate a measurement.
3. Read the Echo: Measure the duration of the HIGH pulse on the Echo pin. The duration is proportional to the distance of the object.
4. Calculate Distance: Use the formula below to calculate the distance: [ \text{Distance (cm)} = \frac{\text{Pulse Duration (µs)}}{58} ]

• Ensure the sensor is powered with a stable 5V DC supply.
• Avoid placing the sensor near ultrasonic noise sources to prevent interference.
• The sensor is waterproof, but the control board is not. Protect the control board from moisture.
• The minimum measurable distance is 20 cm. Objects closer than this may not be detected accurately.

Below is an example of how to use the JSN-SR04T with an Arduino UNO:

// Define pins for the JSN-SR04T sensor
const int trigPin = 9; // Trigger pin connected to digital pin 9
const int echoPin = 10; // Echo pin connected to digital pin 10

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);
  
  // Set pin modes
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop() {
  // Send a 10 µs HIGH pulse to the Trig pin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure the duration of the HIGH pulse on the Echo pin
  long duration = pulseIn(echoPin, HIGH);

  // Calculate the distance in cm
  float distance = duration / 58.0;

  // Print the distance to the Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Wait before the next measurement
  delay(500);
}

• Use a decoupling capacitor (e.g., 10 µF) across the VCC and GND pins to stabilize the power supply.
• If using long wires, consider shielding them to reduce noise.
• Mount the sensor securely to avoid vibrations that could affect measurements.

1. No Output from the Echo Pin:

   • Ensure the Trig pin is receiving a 10 µs HIGH pulse.
   • Verify that the sensor is powered with 5V DC.
   • Check the wiring connections for loose or incorrect connections.

2. Inaccurate Distance Measurements:

   • Ensure there are no obstacles within 20 cm of the sensor.
   • Avoid using the sensor in environments with high ultrasonic noise.
   • Verify that the formula for distance calculation is implemented correctly.

3. Sensor Not Responding:

   • Check if the control board is exposed to moisture. Protect it from water.
   • Test the sensor with a different microcontroller or power source.

Q: Can the JSN-SR04T detect objects closer than 20 cm?
A: No, the minimum measurable distance is 20 cm. Objects closer than this may not be detected accurately.

Q: Is the sensor fully waterproof?
A: The ultrasonic transducer is waterproof, but the control board is not. Ensure the control board is protected from water.

Q: Can I use the JSN-SR04T with a 3.3V microcontroller?
A: The sensor requires a 5V power supply. If using a 3.3V microcontroller, you may need a level shifter for the Trig and Echo pins.

Q: How do I reduce noise in the measurements?
A: Use a decoupling capacitor across the power pins and shield long wires to minimize noise.

By following this documentation, you can effectively integrate the JSN-SR04T ultrasonic sensor into your projects and troubleshoot common issues.