Improving Accuracy in the Readout of Resistive Sensor Arrays

Abstract

The most efficient way to carry out the reading of a set of resistive sensors is to organize them in an array form. This reduces the number of wires to the sum of the number of rows, M, and columns, N, and reading can be carried out using just M+N multiplexers and a single operational amplifier. The drawback in this procedure is the appearance of crosstalk (the influence of the resistance of some sensors on the measurements of others). Although different proposals have been presented in the literature to reduce this phenomenon, errors in determining the resistance values of each sensor still exist in all the proposals. This article presents a new method to determine these values, which considerably reduces errors without the need for any hardware other than the simplest reading circuits. The method consists of a very fast recursive convergence procedure. The results show that the new proposal outperforms other solutions in the first or second step.