sensor for obstacle detection

Thread Starter


Joined Jan 24, 2012
i am doing final year project.
i need an optimum sensor for detecting obstacles at the range of nearly 4metre.
which one i go for?
IR sensor or
ultrasonic sensor.


Joined Feb 28, 2009
First, welcome to the forum. You will find a lot of folks from various backgrounds that are more than willing to help. You will find that you get more assistance if you first provide more information about your present understanding of the topic. As an example for your present inquiry, please state your understanding of each type sensor and what you consider to be the strong and weak points of each approach. I'm sure you will get a reasonable amount of discussion.


Joined Feb 19, 2009
For that distance, ultrasonic will be more accurate. Most LED ranging systems don't reach past 2 meters accurately, it is a non-linear response (due to less and less light hitting the photo-transistor).

Ultrasonic is a linear response based on time, and can go very far with good accuracy if the temp, pressure, and humidity are known.