Improved resistance matrix approach for readout of the two-dimensional resistive sensor array

In the readout circuits of the two-dimensional (2-D) resistive sensor arrays, various auxiliary electrical components were used to reduce their crosstalk errors but resulted in increased circuit complexity. Readout circuits with low-complexity structures were necessary for wearable electronic applications. With only several resistors and a microcontroller, readout circuit based on resistance matrix approach (RMA) achieved low complexity but suffered from small resistance range and large measurement error caused by the output ports’ internal resistances of the microcontroller. For suppressing those negative effects, we firstly proposed an improved resistance matrix approach (IRMA) by additionally sampling the voltages on all driving row electrodes in the RMA. Then the effects of the output ports’ internal resistances and the analog-to-digital converter’s accuracy for the RMA and the IRMA were simulated respectively with NI Multisim 12. Moreover, a prototype readout circuit based on the IRMA was designed and tested in actual experiments. The experimental results demonstrated that the IRMA, though it required more sampling channels and more computations, could be used in those applications needing low complexity, small measurement error and wide resistance range.