Pertanika J. Sci. & Technol. 25 (S): 215 - 224 (2017) SCIENCE & TECHNOLOGY Journal homepage: http://www.pertanika.upm.edu.my/ ISSN: 0128-7680 © 2017 Universiti Putra Malaysia Press. Design of Readout Circuit for Piezoresistive Pressure Sensor Using Nodal Array Approach Reading Technique W. Z. Wan Hasan 1 , F. R. M. Rashidi 1,2 *, M. N. Hamidon and Y. Wahab 3 1 Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia 2 Faculty of Electrical & Electronics Engineering, University Malaysia Pahang, 26600 Pekan, Pahang, Malaysia 3 Centre for Industrial Collaboration, School of Microelectronic Engineering, Universiti Malaysia Perlis, Arau 02600, Malaysia ABSTRACT In this paper, we proposed a new readout circuit in order to improve measurement output while reading the grouped resistive value in matrix array form. The purpose of having this circuit is to overcome the main problem in applying piezoresistive pressure sensor array for foot plantar application. This new approach is called Nodal Array Approach (NAA), a modifed version of Wheatstone Bridge Circuit based on nodal analysis technique using Kirchcoff Current Law. The NAA calculates the sensors’ resistance values by solving simultaneous equations from reading voltages of the proposed readout circuit. Therefore, it is found that the readout circuit connection is of low complexity as it only uses resistive element as the major component of reading technique with only four iterations involved for each voltage nodes. Through simulation results, it shows that NAA is able to achieve high accuracy in obtaining a sensor’s resistance value by adhering to several limitations in order to avoid miscalculation (< 5% average calculation error). Keywords: Resistive readout circuit, resistive sensor array, foot plantar application ARTICLE INFO Article history: Received: 24 August 2016 Accepted: 03 Jun 2017 E-mail addresses: wanzuha@upm.edu.my (W. Z. Wan Hasan), fairuz@ump.edu.my (F. R. M. Rashidi), mnh@upm.edu.my (M. N. Hamidona), yufridin@unimap.edu.my (Y. Wahab) *Corresponding Author INTRODUCTION It has been a trend in medical felds to search for an alternative approach to diagnose a patient without having to probe him/ her with needles for blood samples. This alternative method should be pain-free while still maintaining the same quality as the traditional technique. For an example, by examining foot pressure patterns doctors can tell whether the person has diabetes or not (Aziz et al., 2012; Boulton, 1983). Abnormal brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by UMP Institutional Repository