Accuracy and resolution of direct resistive sensor-to-microcontroller interfaces

The experimental analysis was performed by measuring resistors in the range of Pt1000-type temperature sensors with two commercial microcontrollers (AVR AT90S2313 and PIC16F873). The experimental results were similar for both microcontrollers and agreed with theoretical predictions. For the AVR, the three-signal measurement method yielded a 0.01% relative systematic error and a 0.10 Ω resolution when averaging 10 calculated resistances.