Enhanced interfacing of single element resistive sensor with microcontroller

Abstract

Resistive sensors can be used in a single element, differential and bridge forms. Resistive sensors have wide applications in industries. When the resistive sensor is directly connected with the microcontroller large amount of error arises due to lead wire resistance and microcontroller port pin resistances. Here, an enhanced interfacing of single element resistive sensor with a microcontroller scheme is proposed to compensate the error due to lead wires and port pin resistances. This scheme follows three discharge cycles for the measurement of resistances of the resistive sensor. The time taken for each discharge cycle is noted. From the time taken for the three discharge cycles, the resistance of the resistive sensor is directly calculated. Since the resistances due to lead wires and internal port pin resistances are corrected, the unknown temperature measurement is done accurately.