The piezo is configurable from RCHourglass manager, or via serial port commad SET BEEP [0-255] [0 or 6-30] Set beep notification in ms when passage is detected. Duration 0 = no beep notification. Divider sets beeper frequency: 0 is only pulse, otherwise frequency is 20kHz/divider, where divider must be between 6 and 30.