The number and different types of sensors in cars and smartphones are cited frequently and certainly are impressive. However, sensor usage in many other areas is increasing as well. Appliances, which are not replaced as frequently as vehicles and smartphones, could surprise many people with the different sensing functions and types of sensors used in the latest designs. The addition of these sensors improves efficiency and reliability, enables new capabilities and creates increasingly smarter appliances. One example is a modern washing machine.
A high-end 2020 washing machine can have as many as 14 washing cycles. Several sensors contribute to the subtle and some not so subtle differences between the various cycles and smart function options within each cycle. Sensors also provide fault detection to alert the user to problems.
The first and most visible sensing application is the touch screen. Highly responsive capacitance touch sensors start with a conductively-coated electrode film on a glass panel. Touching the surface, even through gloves, reduces the capacitance and allows the detection of multiple touch points. Correctly interpreting the touch requires a touchscreen controller such as products available from Microchip Technology.
For example, maXTouch® touchscreen controllers are an ideal touchscreen controller for designers who want reliable touchscreen operation on home appliance designs, especially where IEC/UL 60730 Class B functional safety certification is required, according to Chad Solomon, Business Development Manager for Microchip Technology’s Human Machine Interface Business Unit. He recommends products from the ATMXT336UD-MAUHA1 maXTouch touchscreen controller family. Solomon adds, “maXTouch touchscreen controllers also work great in challenging environments with noisy power lines, and even functions with water on the screen or with multiple fingers in thick cooking gloves or oven mitts.”
In a typical appliance application, the Class B touchscreen controller interfaces to a host central processing unit (CPU).
This is just one example of the smart functions added by sensing in the latest appliances. Part 2 will explore other sensors and their added functions.
