A glass breakage detector ensures safety in buildings and homes simply by detecting illegal entry through glass windows and doors. These detectors generally use narrowband microphones to capture and analyze vibrations or acoustic signals produced during a glass breakage. The microphones are generally tuned to the frequencies of glass breakage which vary with the type of glass.
Typical glass breakage detector designs utilize a low-power microcontroller to perform the signal analysis in software. For more complex sound analysis such as frequency composition and peak values, several glass-break sounds are compared with the present profile using signal transforms such as DCT (Discrete Fourier Transform) and FFT (Fast Fourier Transform). A hardware filter is used to restrict the signal spectrum to a particular frequency. A glass breakage alert can be indicated by an onboard buzzer and an LED.
Let’s walk-through some reference designs on Glass-breakage detectors along with their complete documentation:-
Robust Glass-Breakage Detector With Long Battery Life :Â
This reference design from TI describes a robust single-chip glass breakage detector which allows long battery life with low power consumption. The design is built around a low-power MSP430F2274 microcontroller which consumes as low as 50µA average current during monitoring mode. The design performs spectral analysis of a typical glass breakage signal to analyze frequency composition, peak content, and more. An onboard buzzer and an LED provide glass breakage alert. False triggering of the glass-breakage detector is prevented by including an extra thud detection stage for avoiding sound events similar to glass breakage. This reference design includes firmware, hardware design files & other documentation. More on this Reference Design
