Material detection works by sending ultrasonic waves into a material, which bounce back when encountering boundaries or defects. Based on the type of material, the reflected echo can have certain strength. Softer material like fabric or carpet can absorb more sound wave resulting in weaker echo as compared to hard material like ceramic tile or wood. The system analyzes the reflected echoes to identify the relative strength of the received echo which can then be processed to infer the type of material.

For this application the transducer is setup in monostatic configuration, that means same transducer first transmit a burst of ultrasonic pulses and then wait for the echo.

Figure 4-7 shows how an ultrasonic transducer can be configured with LOG300 and a driver circuit for operating an ultrasonic transducer in a monostatic configuration