Proximity sensing in software saves cost and components

Replacing conventional switches and keys with proximity sensors enhances modern product designs, and royalty-free software from Freescale Semiconductor now allows ordinary MCUs to control proximity switches by using GPIOs as inputs.

The software can be hosted on any of more than 300 devices in the Freescale Controller Continuum, including low-end devices. Running alongside the application on the host MCU, the software eliminates the need for a discrete capacitivesensor controller or for a more expensive MCU with an integrated controller. Up to 32 individual sensors can be implemented using MCUs from the Freescale RS08, S08 and V1 ColdFire® portfolios.

Proximity sensors such as linear or rotational sliders, rotary wheels, and touch pads are increasingly implemented within Human-Machine Interfaces (HMI) for diverse types of products.

Since they have no moving parts, benefits can include greater convenience and reliability than conventional knobs and buttons. Using proximity sensors allows the designer greater freedom and reduces overall system cost. The user experience is also enhanced through factors such as contemporary styling and more intuitive controls.

Freescale’s software-based sensing solution allows a wider variety of applications to implement proximity-sensing HMIs, and can be implemented quickly and easily. The source code is downloadable from www.freescale.com.

 

FEATURES Source code built on CodeWarrior™ suite Analogue or digital interface Programmable sampling period Adjustable sensitivity threshold Built-in low-pass filter Buzzer-sound feedback on electrode touch

APPLICATIONS Industrial automation Test equipment Control panels Security systems Domestic appliances Building control and HVAC Home health monitors

 

 

Freescale / Proximity sensor software