SN-HC-SR04 Ultrasonic Ranging Module

[darkconvoy]

Is it possible to use this sensor by putting it an an angle to detect an object or surface? Or do I need a different sensor?

[robosang]

Why don try it?

[sich]

Your system needs to consider whether the object's surface is perpendicular to sensing direction, especially when the surface is flat and smooth. Different sensor has different directional characteristics. It should be stated in the datasheet.

[darkconvoy]

I tried it and when I pointed the sensor at the floor (tiled) at an angle, it does not show any reading but when I put an obstacle in front of it, the sensor can detect it. Any reason or suggestions?

[ober]

That is nature of ultrasonic or infrared sensor. It require reflection from obstacle/object, and there are using wave (sound wave for ultrasonic and light wave for infrared). Wave have reflection angle that we learn in physic. Search for wave reflection and you should understand it. Here is one link: http://www.physicsclassroom.com/class/waves/u10l3b.cfm

[darkconvoy]

Do you have any suggestion on what I should do? Change the sensor type or do something else to improve the reading?

[yonghui]

rotate the ultrasound sensor with a servo to detect in all angle

[darkconvoy]

I want to use the sensor to detect objects/holes at the floor. Any suggestion?

[yonghui]

why dont use camera, write algorithm for object detection.

[darkconvoy]

Can't I use an ultrasonic or infrared to do so?