4.2.4 Defined Event Types

The device assigns the following event types to events.

Table 4.2. Event Type Mapping

Event Type Value

Mapping

0

Sensor activity - touch event

1

Sensor activity - release event

2

Slider activity

Note that this event type value is stored in the lower 4 bits of the first byte of a packet. The upper 4 bits are a packet counter value.

4.2.5 Description Bytes for Touch Events

A touch or release event uses only one byte of the description field. That field identifies which sensor caused the touch or release event

as shown below.

Table 4.3. Touch or Release Event Sensor Mapping

Value

Mapping

0

Capacitive sensing input 0

1

Capacitive sensing input 1

2

Capacitive sensing input 2

3

Capacitive sensing input 3

4

Capacitive sensing input 4

5

Capacitive sensing input 5

6

Capacitive sensing input 6

7

Capacitive sensing input 7

8

Capacitive sensing input 8

9

Capacitive sensing input 9

10

Capacitive sensing input 10

11

Capacitive sensing input 11

4.2.6 Description Bytes for Slider Events

The slider activity description field uses two bytes to describe the position of the slider, which can be any value between 0 (0x0000) and

65534 (0xFFFE). The most-significant byte of this value is transmitted in the first byte (byte 2 of the event packet), and the least-signifi-

cant byte is transmitted second (byte 3 of the event packet).

When the slider is released, a final slider event will be transmitted with 0xFFFF in the two-byte field.

4.2.7 Event Buffer I2C Slave Address

The device's I2C slave address is configurable through the configuration profile. The device will ACK its slave address only when the

interrupt pin is low, signalling that a packet is ready to be read by the host. If the interrupt pin is logic high, the device will not ACK its

slave address.

CPT112S Data Sheet

Functional Description

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