Data Acquisition and Signal Processing for Smart Sensors

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DIGITAL OUTPUT SMART SENSORS WITH SOFTWARE-CONTROLLED PERFORMANCES AND FUNCTIONAL CAPABILITIES

Digital systems are being ever-increasingly used for measurement and control applications. However, all the variables in the ‘real world’ which sensors are used to measure (such as temperature, pressure, flow or light intensity) are analog in their physical nature: an element is therefore always needed to link the analog environment to the digital system. This usually also means that signals from sensors must be appropriately modified, so as to be made suitable for conversion into a digital data format.

The interface from the analog domain to the digital domain can be a mystifying design problem. The hardware design and the software must operate together to produce a complete, usable design. It is especially true for the smart sensor design. Here the hardware and the software are needed to implement the bridge between the system analog signals and the digital signals.

The use of frequency-to-code converters based on the so-called program-oriented conversion methods (PCM) in combination with frequency output sensors and transducers of electric and non-electric quantities by the creation of smart sensors with embedded microcontrollers was considered earlier (Figures 1.2, 3.7), and seems to promise a lot. In this case, the conversion error is determined by the sensor's accuracy. The hardware or the chip area can be reduced to the minimum possible (the microcontroller core and peripherals). ...