SX8635I05AWLTRT SEMTECH [Semtech Corporation], SX8635I05AWLTRT Datasheet - Page 16

• Manufacturer Part Number: SX8635I05AWLTRT
• Description: Low Power, Capacitive Button and Wheel Touch Controller with Enhanced LED
• Manufacturer: SEMTECH [Semtech Corporation]

SX8635
Low Power, Capacitive Button and Wheel Touch Controller
(12 sensors) with Enhanced LED Drivers and Proximity Sensing
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
....x...
position
Wheel Position
Figure 13
The position belonging to the minimum and associated to a sensor is defined arbitrarily. The SX8635 defines the
minimum position to the sensor with the lowest CAP pin index. E.g. if CAP0 is a button (or disabled) and CAP1 to
CAP7 are the sensors of the wheel then the position ‘zero’ starts at CAP1 and the maximum is found at CAP7.
In addition to the wheel position, the SX8635 allows to detect finger rotation. The rotation occurs if the finger
position changes a certain step size between two succeeding scan periods. A very slow moving finger will not be
considered as a rotation as the changing position will be minor. The SX8635 allows detecting a rotate clockwise
(direction min to max) (see Figure 14) and a rotate counter clockwise (direction max to min) (see Figure 15).
rotate clockwise
Wheel rotate clockwise
Figure 14
Wheel rotate counter clockwise
Figure 15
Revision 7_8, October 10
© 2010 Semtech Corp.
www.semtech.com
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