High-sensitivity touch key MCUs measure the capacitance between two electrodes, replacing sensors
Renesas Electronics, a premier supplier of advanced semiconductor solutions, introduced its Material Detection Solution, which can detect materials or liquids easily and cost effectively without sensors by connecting electrodes using Renesas’ RX130 capacitive touch-key microcontrollers (MCUs).
Replacing the sensors with this electrode approach contributes to lower bill of materials (BOM) costs while enabling detection at multiple points using a single chip. This allows industrial equipment, OA equipment, and home appliance manufacturers to explore detection systems for cost-constrained applications.
Renesas’ touch-key MCUs feature a capacitive touch sensor unit specialized 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 a powder such as vacuum cleaner dust, a liquid such as refrigerator and coffee maker, or material such as paper 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.
As sensor-based technology proliferates in industrial equipment, OA equipment, and home appliances, the demand for different types of sensor solutions is rapidly increasing to address diverse sensing needs. For instance, printers are required to detect the remaining amounts of consumable materials and inform users in advance when replacements are required. Vacuum cleaners also need to manage the accumulation of dust retained by vacuum cleaner filters in order to perform efficient cleaning. This provides improved device functionality and increased user convenience.
Although these applications can be implemented by using various types of sensors, such as pressure sensors for detecting physical objects, photosensors, IR sensors, and CMOS sensors, the use of multiple sensors creates additional cost and heavy development burdens.
- 2 thin-film electrodes are connected and the capacitance between those electrodes is measured.
- Initialization and sensitivity adjustments can be easily performed using the GUI tool
Material Detection Solution includes design support materials:
- Electrode interface circuit diagrams
- Sample program
- Guidelines for the newly implemented detection functions