*Ph.D., Asst. Professor, Department of Electrical & Computer Engineering, College of Engineering & Tech, Aksum University, Axum, Ethiopia and North East Africa
**Principal and Professor, CSE Department, Anwarul-uloom College of Engineering & Technology, Yennepally, Vikarabad, RR Dist., A.P., India
***M.Tech. Senior Lecturer, Department of Electrical & Computer Engineering, Jigjiga University, Jigjiga, Ethiopia, North East Africa
****Ph.D., Associate Professor, Department of Electronics and communication Engineering, Joginpally B.R Engineering college, Moinabad, Rangareddy Dist, Hyderabad, Andrapradesh, India
Online published on 11 December, 2013.
Ultrasonic range finder works by transmitting a short pulse of sound at a frequency inaudible to the ear ultrasonic sound or ultrasound. Afterwards the microcontroller listens for an echo. The time from transmission to echo reception lets you calculate the distance from the object. The project uses 5 standard transistors to receive and transmit the ultrasound and a comparator to set the threshold echo detection level - so there are no special components other than the microcontroller. The ultrasonic transducers are standard 40kHz types. You can get ultrasonic transducers optimized for 25kHz, 32kHz, 40kHz or wide bandwidth transducers. This project uses a 40kHz transducer but it will still work with the others if you make simple changes to the software (where it generates the 40kz signal). The receiver and generator circuits will work as they are. The 40kz signal is easily generated by the microcontroller but detection requires a sensitive amplifier. The maximum distance is limited by the sensitivity, gain and noise performance of the receive amplifier and also the transmit power and duration of transmission.
Transmission, Sensitivity, Ultrasound, Transducer, Gain
