Datasheet

8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
Revision 1.32 (01-05-12) 72 SMSC CAP1188
DATASHEET
is changed so that it is unlinked, it will check the status of the corresponding LED Output
Control bit. If that bit is ‘0’, then the LED will behave as if a release was detected. Likewise,
if an unlinked LED was actuated by the LED Output Control register and the control is
changed so that it is linked and no touch is detected, then the LED will behave as if a release
was detected.
5.31.1 LED Behavior 1 - 81h
Bits 7 - 6 - LED4_CTL[1:0] - Determines the behavior of LED4 as shown in Table 5.52.
Bits 5 - 4 - LED3_CTL[1:0] - Determines the behavior of LED3 as shown in Table 5.52.
Bits 3 - 2 - LED2_CTL[1:0] - Determines the behavior of LED2 as shown in Table 5.52.
Bits 1 - 0 - LED1_CTL[1:0] - Determines the behavior of LED1 as shown in Table 5.52.
5.31.2 LED Behavior 2 - 82h
Bits 7 - 6 - LED8_CTL[1:0] - Determines the behavior of LED8 as shown in Table 5.52.
Bits 5 - 4 - LED7_CTL[1:0] - Determines the behavior of LED7 as shown in Table 5.52.
Bits 3 - 2 - LED6_CTL[1:0] - Determines the behavior of LED6 as shown in Table 5.52.
Bits 1 - 0 - LED5_CTL[1:0] - Determines the behavior of LED5 as shown in Table 5.52.
Table 5.52 LEDx_CTL Bit Decode
LEDX_CTL
[1:0]
OPERATION DESCRIPTION
START
TRIGGER
STOP
TRIGGER1 0
0 0 Direct
The LED is driven to the programmed state
(active or inactive). See Figure 5.7
Touch Detected
or LED Output
Control bit set
Release
Detected or
LED Output
Control bit
cleared
0 1 Pulse 1
The LED will “Pulse” a programmed
number of times. During each “Pulse” the
LED will breathe up to the maximum
brightness and back down to the minimum
brightness so that the total “Pulse” period
matches the programmed value.
Touch or
Release
Detected or LED
Output Control
bit set or cleared
(see
Section 5.32)
n/a
1 0 Pulse 2
The LED will “Pulse” when the start trigger
is detected. When the stop trigger is
detected, it will “Pulse” a programmable
number of times then return to its minimum
brightness.
Touch Detected
or LED Output
Control bit set
Release
Detected or
LED Output
Control bit
cleared
1 1 Breathe
The LED will breathe. It will be driven with
a duty cycle that ramps up from the
programmed minimum duty cycle (default
0%) to the programmed maximum duty
cycle duty cycle (default 100%) and then
back down. Each ramp takes up 50% of the
programmed period. The total period of
each “breath” is determined by the LED
Breathe Period controls - see Section 5.34.
Touch Detected
or LED Output
Control bit set
Release
Detected or
LED Output
Control bit
cleared