A method to determine a physical quantity within a measuring space by means of acoustic transit time measurement uses an acoustic transducer as a transmitter and an acoustic transducer as a receiver. The method includes determining a vector of one-shot code coordinates of the mobile rover. The device initializes at start-up in the promiscuous mode to learn the MAC address of the router and subsequently accepts data packets destined to the router for internal processing. A second portion of the first data can be selected based at least in part on the cell scrolling display value, and a second portion of the second data can be selected based at least in part on the cell scrolling display value.