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JSN SR-04T Waterproof Ultrasonic Sensor

JSN-SR0T4 is a waterproof ultrasonic distance measurement sensor module with a range of 25cm-450cm non-contact distance measurement. It is very similar to the ultrasonic sensors which are found in car bumpers. It works with a nominal 4.5V to a maximum of 5.5 VDC supply voltage. However, it typically works with 5.0V DC voltage and requires a maximum of 30mA current.


Pin Description of JSN SR-04T

S. NO.

Pin Name

Pin Description



Positive supply pin of the sensor



Input pin of sensor. This pin has to be kept high for 10us to initialize measurement by sending ultrasonic waves.



Output pin sensor. This pin goes high for a period that will be equal to the time taken for the ultrasonic wave to return to the sensor.



This pin is connected to the Ground of the system.


Features and Specification of JSN SR-04T

  • Operating voltage: DC 5V
  • Quiescent current: 5mA
  • Total current draw: 30mA
  • Frequency: 40khz
  • Range: 25cm to 450cm
  • Beam Angle: less than 50 degrees
  • Working temperature: -10 ~ 70 Celsius
  • Storage temperature: -20 ~ 80 Celsius
  • Small size, easy to use
  • Low voltage, low power consumption
  • Strong anti-jamming
  • Integrated with wire enclosed waterproof probe, suitable for wet, harsh measurement occasions


Note: Complete technical details can be found in the JSN SR-04T Waterproof Ultrasonic Sensor Datasheet linked at the bottom of this page.


Equivalent to JSN SR-04T

HC-SR04 Ultrasonic Sensor


Alternative for JSN SR-04T

US transmitter-Receiver pair, IR sensor module, IR sensor pair, IR Analog distance sensor


JSN SR-04 Ultrasonic Sensor - Working

JSN SR-04T Sensor

JSN SR-04 Sensor’s working is same as HC-SR04. But JSN SR-04 sensor has only one transducer that is connected through a 2.5 Meter cable. This sensor module comes in two separate parts; one being the transducer, which is the sensing element, and the other being the control board. The sensor works with the simple high school formula-

Distance = Speed × Time

The Ultrasonic transmitter transmits an ultrasonic wave. This wave travels in air and when it gets objected by any material, it gets reflected back toward the sensor, this reflected wave is observed by the Ultrasonic receiver module. Now, to calculate the distance using the above formulae, we should know the Speed and time. Since we are using the Ultrasonic wave, we know the universal speed of US wave at room conditions which is 330m/s. The circuitry inbuilt on the module will calculate the time taken for the US wave to come back and turns on the echo pin high for that same particular amount of time. This way, we can also know the time taken. Now simply calculate the distance using a microcontroller or microprocessor.


How to use the JSN-SR04 Waterproof Ultrasonic Sensor

As mentioned earlier, this sensor’s Pin-out and working are similar to the HC-SR04 distance sensor. It can be interfaced with microcontrollers like Arduino, ARM, PIC, Raspberry Pi, etc.

JSN-SR04 Waterproof Ultrasonic Sensor Working

Power the Sensor using a regulated +5V through the VCC ad Ground pins of the sensor. The Trigger and the Echo pins are both I/O pins and hence they can be connected to the I/O pins of the microcontroller. To start the measurement, the trigger pin has to be made high for 15uS and then turned off. This action will trigger an ultrasonic wave at a frequency of 40Hz from the transmitter and the receiver will wait for the wave to return. Once the wave is returned after it getting reflected by any object, the Echo pin goes high for a particular amount of time which will be equal to the time taken for the wave to return back to the sensor.


The amount of time during which the Echo pin stays high is measured by the MCU/MPU as it gives information about the time taken for the wave to return back to the Sensor. Using this information, the distance is measured as explained in the above heading.


Applications of JSN-SR04

This sensor can be used in:

  • Horizontal Ranging
  • Obstacle Avoidance
  • Automated Control
  • Monitoring of objects and their movement


2D Model of JSN SR-04T

Dimensions for the JSN SR-04T are given below. It can be used to design custom footprints of the module.

JSN SR-04T Dimensions

Component Datasheet

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