Ultrasound has many advantages, such as the nice directivity, the slow energy consumption, the slow propagation speed(about 340 m/s, as same as the speed of sound), and the long transmission distance. Measuring distance with ultrasonic is unnecessary to contact with the object directly, so it is widely used currently. It is used in robot’s visual identity, vehicle automatic navigation, construction measurement and so on.
The article describes the concept of ultrasound, ultrasonic transducer, the principles of ultrasonic ranging, and the performance and the features of the ATmega16 MCU(especially the part of timer). And analysis the ultrasonic ranging system which is designed on the basis of AVR microcontroller. The design of the system circuit is reasonable, and can work stable. It has good performance and simple calculation. At the same time, it can meat the requirements when precision is required in a certain extent.
