ATMEGA ULTRASONIC RANGE FINDER FAKHRUL ADLEE BIN ...

52.4 Ultrasonic TransmitterThe transmitter consists of an electronics circuitry and an electromechanicaltransducer.The electronic circuitry generates the required frequency electrical signaland the electromechanical transducer converts that electrical signal into the physicalform and activates the open medium surface. This oscillating physical surfacecreates the ultrasonic Waves. The oscillating surface creates a pressure variation andultimately a pressure wave with a frequency equal to that of the surface oscillation.Figure 2.3: The transmitter circuit design.The transmitter was designed to oscillate at a resonant frequency of about 40KHz. The 555 timer generates a 40 KHz sinusoidal ultrasonic wave.