HC-SR04 Ultrasonic Proximity sensor
HC-SR04 Ultrasonic Proximity Sensor 2

HC-SR04 Ultrasonic Proximity Sensor

4.91 out of 5
(11 customer reviews)


SKU: 3204584. Category: . Tags: , , , , .

Product Description

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

11 reviews for HC-SR04 Ultrasonic Proximity Sensor

  1. 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. 5 out of 5

    (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. 5 out of 5

    (verified owner):

    Nice sensor
    good price

  4. 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. 5 out of 5

    (verified owner):

    Very good price, good quality and works very well :)

  6. 5 out of 5

    (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. 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. 5 out of 5

    (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. 5 out of 5

    (verified owner):

    Good, stable and accurate ultrasonic sensor

  10. 5 out of 5

    (verified owner):

    Works like a charm.
    Very good product!

  11. 4 out of 5

    (verified owner):

    Great product,very easy to use

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