User guide

18 Document No. 001-64846 Rev. *A Getting Started with CapSense®
2.5.2.3 Radial Sliders
Radial sliders are similar to linear slider in that finger position is estimated using data from adjacent sensors,
however, radial sliders are continuous (no beginning or end).
Figure 2-16. Radial Slider
Area contacted by finger
2.5.3 Touchscreens and Trackpads (Two-Dimensional Sensors)
Cypress’s TrueTouch™ touchscreen solutions use mutual capacitance sensing. Visit TrueTouch™ Touch Screen
Controllers to learn about these products. Cypress also offers trackpad solutions. Contact your local Cypress sales
office directly for more information. To find your local sales office click here.
2.5.4 Proximity (Three-dimensional Sensors)
Proximity sensors detect the presence of a hand or other conductive object before it makes contact with the touch
surface. Imagine a hand stretched out to operate a car audio system in the dark. The proximity sensor causes the
buttons of the audio system to glow via backlight LEDs when the user's hand is near. One implementation of a
proximity sensor consists of a long trace on the perimeter of user interface, as shown in Figure 2-17.
Figure 2-17. Proximity Sensor
Another way to implement a proximity sensor is by ganging sensors together. This is accomplished by combining
multiple sensor pads into one large sensor using firmware to connect the sensors from the internal analog multiplexer
bus. Care must be taken not exceed the C
P
limit for the sensing method when ganging sensors together.