Development of Readout Circuit Using Nodal Array Approach (NAA) for Five Resistive Sensors Arrangement

This paper applies a readout circuit to improve measurement output when reading the grouped resistive value in a matrix array format. The circuit is designed to address the main challenge faced in utilizing resistive pressure sensor arrays for fingertips pressure point applications. The proposed approach, called the Nodal Array Approach (NAA), modifies the Wheatstone Bridge Circuit using nodal analysis technique and Kirchhoff’s Current Law. By solving simultaneous equations derived from the voltage readings of the readout circuit, the NAA accurately calculates the resistance values of the sensors. The readout circuit connection is of low complexity, utilizing resistive elements as the major components of the reading technique with only three iterations involved for each voltage node. Hardware results demonstrate that the NAA achieves high accuracy in obtaining a sensor’s resistance value, while adhering to several limitations to avoid miscalculation with an average calculation error of less than 5%.