It connects two thin-film electrodes and measures the capacitance between those electrodes. Changes in the measured materials are determined by detecting the change in capacitance between the electrodes. Using this electrode approach contributes to lower BOM costs while enabling detection at multiple points using a single chip.
The touch-key MCUs feature a capacitive touch sensor unit specialized for capacitance measurement with high sensitivity and high noise resistance. This enables the Material Detection Solution to easily detect the presence or absence of a powder by measuring the capacitance between electrodes to the MCU. The increase or decrease of the powder, liquid, or material will change the capacitance value between the electrodes.
In addition to eliminating the need for sensor evaluation and operating condition determination, the initialization and sensitivity adjustments can be easily performed using the development support GUI tool available for capacitive touch sensor systems.
The Renesas Material Detection Solution includes electrode interface circuit diagrams, sample programs and guidelines for the newly implemented detection functions.