HC-SR04 Ultrasonic Proximity Sensor

Rated 4.93 out of 5 based on 14 customer ratings
(14 customer reviews)


SKU: SMO1058 Category: Tags: , , , ,


Reliable, high performance, high accuracy, blind area within 2cm


  • Voltage:DC5V
  • Current:less 2mA
  • TTL:higher 5V
  • Sensing angle:Less than 15 degree
  • Sensing distance:2cm-450cm
  • Accuracy:about 0.3cm
  • PCB Dimension:4.5*2.0CM
  • Connection:  VCC, trig(Control),   echo(Receive), Out, GND

Working principle:

  • Send high TTL signal at trigger IO.
  • Module automatically send 8*40khz squre wave in order to detect if there are any signal return.
  • when signal return, use each(receive) IO pin output high TTL, the output TTL time length is the time from sending till return.
    • try to use this fomula: distance = (high TTL time* velocity of sound)/2
    • velocity of sound = 340m/s


See more at this wiki page.

Additional information

Weight 0.008 kg

14 reviews for HC-SR04 Ultrasonic Proximity Sensor

  1. Rated 5 out of 5


    Good, stable and accurate ultrasonic sensor. Needed it for switching on/off a project if someone was in a range of 0 to 30 centimetres. Works like a charm. And like all the stuff you can find here, the price is unbeatable.

  2. Rated 5 out of 5

    Sachin (verified owner)

    Nice product! These sensors are capable of measuring up to a range of 4 mts or more. Good quality product at affordable price.

  3. Rated 5 out of 5

    koursaros (verified owner)

    Nice sensor
    good price

  4. Rated 5 out of 5


    This is a very good sensor that is good for starting robotics people allowing them to develop robots that can sense its surroundings.

  5. Rated 5 out of 5

    schnetzi (verified owner)

    Very good price, good quality and works very well 🙂

  6. Rated 5 out of 5

    dancewicz.grzegorz (verified owner)

    Really good one, I used it to support my wife with car park in our garage – blinks the Red/Yellow/Green LED depending on distance to the wall left. Of course great price!

  7. Rated 5 out of 5


    This is a very good sensor that can be used for a lot of robotics purposes. Its sensing distance is not that far, but good for smaller robotics projects, google for the biped robot “BOB” the biped. It’s a very simple robot that can be built with the micro servos available here and also this sensor.

  8. Rated 5 out of 5

    yfands (verified owner)

    Well Build and cheap, if you’re using an Arduino, try this library
    I was able to measure within 2 – 273 centimeters.

  9. Rated 5 out of 5

    cromdeveloper (verified owner)

    Good, stable and accurate ultrasonic sensor

  10. Rated 5 out of 5

    jpoilux (verified owner)

    Works like a charm.
    Very good product!

  11. Rated 4 out of 5

    alexbunodiere (verified owner)

    Great product,very easy to use

  12. Rated 5 out of 5

    Christoph (verified owner)

    The classic HC-SR04. Robust, reliable and accurate. I use one to measure the water level in my cistern.

  13. Rated 5 out of 5

    geraldhasmail (verified owner)

    Excellent! Very easy to set up with Arduino, great for measuring the height of fluid in a tank if you don’t want to get a sensor wet.

  14. Rated 5 out of 5


    Must have in any project !

Add a review

Your email address will not be published. Required fields are marked *

Product Enquiry