@article {Chang:2012:1546-198X:1282,
title = "A Smart Detection Interface for Processing Universal Electrical Sensor Signal",
journal = "Sensor Letters",
parent_itemid = "infobike://asp/senlet",
publishercode ="asp",
year = "2012",
volume = "10",
number = "5-6",
publication date ="2012-05-01T00:00:00",
pages = "1282-1287",
itemtype = "ARTICLE",
issn = "1546-198X",
eissn = "1546-1971",
url = "https://www.ingentaconnect.com/content/asp/senlet/2012/00000010/f0020005/art00040",
doi = "doi:10.1166/sl.2012.2285",
keyword = "MICROCONTROLLER-BASED SENSING, ELECTRICAL SENSORS, SMART INTERFACE, SENSOR SIGNAL PROCESSING",
author = "Chang, Hsing-Cheng and Hung, San-Shan and Wang, Te-Wei and Lai, Chi-Chih and Chang, I-Nan",
abstract = "A low-cost microcontroller-based smart interface for processing electrical analog signal is described to measure real-time sensor's parameters automatically. In the smart interface, an electrical sensing type of resistive, capacitive or inductive signal can be determined by setting
matched resistance and using phase shift comparative method. The method is based on operation of synchronous phase comparator and auto-adjustment optimal bridge resistance at frequency of 1 kHz or 100 kHz. The microcontroller with embedded timer can measure the difference of phase shift with
the minimum error analysis to evaluate the properties of sensors. An electrical sensor with an optimal matched resistance formed a half bridge structure which supplied independent values to comparators for microcontroller calculation in succession. The developed interface is economical which
consists of only three active components: a programmable microcontroller, two comparators and an A/D converter. A prototype of the smart interface can be easily modified for universal sensor application. Experimental error is minimized by using auto calibration and error comparison technology.
Periodic bow-shaped error distributions are observed on experimental signal measurements that provide optimal feasibility in electrical sensing devices with the minimum error. For the prototype built in specified measurement range, the reproducible overall uncertainties of \textpm0.224%,
\textpm0.138% and \textpm0.557% to resistive, capacitive and inductive sensing signals have been achieved. The rms errors of 0.67%, 0.64% and 4.34% are obtained in resistive, capacitive and inductive measurements respectively.",
}