Understanding Smart Sensors - Nomads.usp

302 Understanding Smart SensorsSTIMTEDSEEPROMADCPressuresensorMicrocontrollerTEDSaccessControl anddispatchDataacquisition1451.2driverNCAPWeb pageserver1451.2interfaceroutines1451.2driver1451.2 digitalinterfaceNetworkdriverCorrectionengineEthernetPCWeb pagebrowserFigure 13.3 Reference implementation of IEEE 1451. (After: [9].)raw sensor readings from the STIM. The NCAP’s Web page is viewed bypointing a Web browser at the NCAP. The prototype supports a wide varietyof analog sensors.13.4.1 Wireless ProtocolSome remote measurements and wireless sensing applications may requiremore industry effort or benefits to make the standard attractive. For example, asingle-chip wireless sensor that transmits sensor information in shipboard conditionsdoes not—at this time—use IEEE 1451 [10]. As shown in Figure 13.4,the fully integrated wireless sensor has four different sections: (1) sensors andfront-end signal processing, (2) digitization, control, and spreading-code generation,(3) RF transmitter, and (4) the antenna. The lower left corner is anarea designed to be sensitive to a specific frequency of an IR signal. The chipcontains a communication protocol that allows a TV-style remote to programthe sample rate, analog gain, and other parameters. The design has reliably collectedand transmitted data over three decks of a ship without incurring EMIproblems. Section 13.6 discusses alternative standards.13.4.2 Remote DiagnosisRemote measurements are allowing physicians to analyze and treat patients inremote areas [11]. Applications for that approach include transmission from anoverseas battlefield or work site, telemedicine for hospitals in rural areas, remote