EVISION Obstacle Detector

Obstacle Detector is a distance-measuring system based on ultrasonic sound utilizing the LPC2364FBD100. The system transmits a burst of ultrasonic sound waves towards the subject and then receives the corresponding echo. The LPC2364FBD100 integrated analog comparator is used to detect the arrival of the echo to the system. The time taken for the ultrasonic burst to travel the distance from the system to the subject and back to the system is accurately measured by the LPC2364FBD100. Assuming the speed of sound in air at room temperature to be 1100 ft/s, the LPC2364FBD100 computes the distance between the system and the subject and gives the information to buzzer. The minimum distance that this system can measure is eight inches and is limited by the transmitter’s transducer settling-time. The maximum distance that can be measured is 2 meter. The amplitude of the echo depends on the reflecting material, shape, and size. Sound-absorbing targets such as carpets and reflecting surfaces less than two square feet in area reflect poorly. The maximum measurable range is lower for such subjects. If the amplitude of the echo received by the system is so low that it is not detectable by the Comparator. This system is mainly used to replace normal sticks for the visually impaired (blind) peoples. This unit has standard USB 2.0 for mobile interface and has android application for user interface