Touch sensing is fast becoming an alternative to traditional pushbutton switch user interfaces, because it requires no mechanical movement, and it enables a completely sealed and modern- looking design. Expanding beyond the consumer market, touch sensing is beginning to take hold in medical, industrial and automotive applications for reasons such as aesthetics, maintenance, cost and cleanliness. Cypress PSOC, provides a free and easy method for designers to add touch sensing to applications utilizing their microcontrollers without the cost of fee-based licensing and royalty agreements. Being a source-code solution further helps engineers quickly integrate touch sensing functionality with their existing application code in a single, standard microcontroller, thus reducing the total system cost associated with current solutions.
Capactive Switch basically is a pair of adjacent plates (please refers below figure). Small edge to edge capacitance is present, the intent of the switch layout is to minimize the capacitance between these plates. When a conductive object like figure is placed in proximity to the two plates, (refer fig. B), there is a capacitance between one electrode and the conductive object and a similar capacitance between the conductive object and the other electrode.
The most common form of capacitance switch array is a set of capacitors where one side of each is grounded. Thus the active capacitor has only one accessible side; the switch is grounded variable capacitor.The presence of the conductive object increases the capacitance of the switch to ground. The switch action is determined by measuring the change in the capacitance. Capsense technology can be applied to varies applications, such as –
The function of a button is to determine the presence or absence of a conductive object. A typical application of a Capsense button is to sense the presence of a finger.
A slider is a sensor array. Changes between adjacent capacitive elements are used to determine the position of a conductive object
The Capsense user module does not directly support touchpads. Touch pads are implemented as two independent sliders.
The Capsense user module does not directly support proximity sensors. A proximity sensor is implemented as a Capsense button with large
Cp and small difference counts.
• Appliance Controls
• Industrial Keyboards
• Outdoor Keypads
• Security Key Panels
• Automotive Interior Controls
Keetronics offers, following output solutions.