Capacitive Touch Through Metal Using MSP430™ MCUs With CapTIvate™ Technology (Rev. A)
MSP430 microcontrollers (MCUs) with CapTIvate technology from Texas Instruments provide a high-sensitivity capacitive touch solution with high reliability and noise immunity at the lowest power.
This application report demonstrates a new capacitive touch application through metal overlays using CapTIvate technology. Microscopic movements in a flat metal can be sensed and processed to determine how hard a given button was pressed due to the high sensitivity and resolution of TI's technique. This approach allows reuse of existing metal surfaces commonly found in many applications such as building security systems, appliances, and consumer electronics.
The document describes the fundamentals of TI's CapTIvate technology-based metal touch technique and provides guidance on how to design a touch on metal panel with MSP430 MCUs featuring CapTIvate technology. Applications and noise immunity considerations are also discussed in this document.
This application report assumes that readers are reasonably familiar with elementary capacitive touch principles, CapTIvate technology, and MSP430 microcontroller architecture.