Simple Two-Wire Lead Compensation for Resistive Sensors Using Microcontroller ADCs
Apinan Aurasopon, Wanchai Khamsen, Chiraphon Takeang, Jaime Lloret · IEEE Sensors Journal · 2025
This article introduces a simplified two-wire measurement system for accurate resistance measurement of resistive sensors, leveraging the Anderson current loop. The proposed configuration features a precision reference resistor (${R}_{\text {ref}}$) and two diodes (${D}_{{1}}$and${D}_{{2}}$), directly interfaced with the analog-to-digital converter (ADC) and output pins of a microcontroller, eliminating the need for external stabilization resistors. Utilizing ratiometric voltage measurements and an adaptive tuning factor, the system effectively compensates for lead-wire resistance and diode mismatches. A prototype implemented with an ATmega2560 microcontroller demonstrates accurate resistance measurements in the range of 60–$320~\Omega $, corresponding to a Pt100 sensor, achieving an uncertainty error of less than 0.13% for a lead-wire resistance of$4.87~\Omega $and 0.15% for$10.0~\Omega $. Experimental results confirm the system’s precision and reliability over long lead lengths, offering a cost effective and robust solution for industrial and remote sensing applications requiring accurate temperature measurements.