Capacitive sensor foils evaluation – the Wöhr® standard controller

Whether machine builders, medical professionals, or building technicians, those who need durable and robust input systems in their daily work are increasingly relying on touch input. Intuitively operable touch input systems are conquering the market – Richard Wöhr GmbH continues to set trends here, offering not only the possibility to produce custom touch solutions but also a capacitive standard controller. This evaluates and outputs the signals from an arbitrarily configurable sensor foil. Wöhr® additionally offers a standard sensor foil with 16 individual buttons (Article number: WSCONCAP01). This optionally available foil can be cut to the desired number of 1 to 16 buttons based on a pattern. The foil is self-adhesive on the front side and can thus be quickly and easily glued behind any insulating surface (for example: glass, acrylic, plastic, wood, etc.). After connection, it is immediately operational. Another advantage of the sensor foil is that the button surfaces are transparent, and if desired, the buttons can be backlit. If this is not desired, the sensor surface can alternatively be printed in non-transparent silver conductor technology.

The capacitive standard controller developed and produced in-house by Wöhr is powered via USB or a 5V connector. The controller is compatible with Arduino™ shields and features a USB interface with HID protocol. It has 16 inputs for sensor fields and 16 digital outputs as feedback for the respective buttons. Additionally, it has an output that is set with each button press. This can be used as an interrupt, for example, for haptic or acoustic feedback. The system is modular, so extensions such as a relay board can be easily plugged in. It is possible to evaluate or connect up to 16 individual buttons, a 4-channel slider, 12 buttons, or 1 wheel and 10 buttons.

Possible Applications:

- as a replacement for mechanical buttons/switches
- in hygienically demanding environments (e.g., medical, food industry, etc.)
- in vandalism-prone areas

Advantages:

- Operation by light touch without pressure, e.g., by pressing on glass
- No moving parts, no mechanical wear
- Enclosed front, easy to clean
- Resistant to chemicals, contamination, vandalism