the art of directly interfacing sensors to microcontrollers微控制器直接连接传感器的艺术.pdf

J. Low Power Electron. Appl. 2012, 2, 265-281; doi:10.3390/jlpea2040265 OPEN ACCESS Journal of Low Power Electronics and Applications ISSN 2079-9268 /journal/jlpea/ Review The Art of Directly Interfacing Sensors to Microcontrollers Ferran Reverter Castelldefels School of Technology, Universitat Politècnica de Catalunya, C/Esteve Terradas, 7, Castelldefels 08860, Barcelona, Spain; E-Mail: ferran.reverter@; Tel.: +34-93-413-70-76; Fax: +34-93-413-70-07 Received: 24 September 2012; in revised form: 17 October 2012 / Accepted: 19 November 2012 / Published: 29 November 2012 Abstract: This paper reviews the direct connection of sensors to microcontrollers without using any analogue circuit (such as an amplifier or analogue-to-digital converter) in the signal path, thus resulting in a low-cost, lower-power sensor electronic interface. It first discusses the operating principle and explains how resistive and capacitive sensors with different topologies (i.e., single, differential and bridge type) can be directly connected to a microcontroller to build the so-called direct interface circuit. It then shows some applications of the proposed circuits using commercial devices and discusses their performance. Finally, i