Detection solution uses electrodes with touch-key MCUs to ‘sense’ liquids and solid materials

By Gina Roos, editor-in-chief

Renesas Electronics Corp. has unveiled a material-detection solution that can detect materials or liquids without sensors by connecting electrodes using Renesas’s RX130  capacitive touch-key microcontrollers (MCUs). By replacing sensors with the electrode approach, it enables low-cost detection at multiple points using a single chip while lowering bill of materials (BOM) costs, said Renesas. Applications include industrial and office automation (OA) equipment as well as home appliances.

The solution works by connecting two thin-film electrodes and measuring the capacitance between the electrodes using a touch-key MCU. Changes in the measured materials are determined by detecting the change in capacitance between the electrodes.

The touch-key MCUs feature a capacitive touch sensor unit  that is designed for capacitance measurement with extremely high sensitivity and high noise resistance. This enables the material-detection solution to easily detect the presence or absence of solid materials such as vacuum cleaner dust or liquid in a coffee maker by measuring the capacitance between the electrodes to the MCU. The increase or decrease of the material changes the capacitance value between the electrodes.

Although sensor-based technologies like IR sensors, CMOS sensors, or photosensors can be used for these applications, Renesas expects that the new detection solution will find homes in industrial, OA, and home appliance applications as the demand for different sensing applications rise, along with the need for low-cost solutions.

Renesas provides design support that includes electrode interface circuit diagrams, a sample program, and guidelines for the detection functions. The material-detection solution is available now for free download here . More information about the company’s capacitive touch-key solutions is available here .