8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
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.
APPLICATION NOTE: If the period for any breathe operation is changed while the LED is actuated, then the LED
output will be reset to 0% drive and any breathing will re-initiate at the new settings. For
Pulse 1 and Pulse 2 behaviors, the number of pulses will be retained.
5.27.1
LED Behavior 1 - 81h
Bits 7 - 6 - LED4_CTL[1:0] - Determines the behavior of LED4 as shown in Table 5.43.
Bits 5 - 4 - LED3_CTL[1:0] - Determines the behavior of LED3 as shown in Table 5.43.
Bits 3 - 2 - LED2_CTL[1:0] - Determines the behavior of LED2 as shown in Table 5.43.
Bits 1 - 0 - LED1_CTL[1:0] - Determines the behavior of LED1 as shown in Table 5.43.
5.27.2
LED Behavior 2 - 82h
Bits 7 - 6 - LED8_CTL[1:0] - Determines the behavior of LED8 as shown in Table 5.43.
Bits 5 - 4 - LED7_CTL[1:0] - Determines the behavior of LED7 as shown in Table 5.43.
Bits 3 - 2 - LED6_CTL[1:0] - Determines the behavior of LED6 as shown in Table 5.43.
Bits 1 - 0 - LED5_CTL[1:0] - Determines the behavior of LED5 as shown in Table 5.43.
Table 5.43 LEDx_CTL Bit Decode
LEDX_CTL
[1:0]
START
TRIGGER
STOP
TRIGGER
1
0
OPERATION
DESCRIPTION
Release
Detected or
LEDControl
bit cleared
Touch Detected
or LED Control
bit set
The LED is driven to the programmed state
(active or inactive). See Figure 5.5
0
0
Direct
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 (See
Section 5.31) or
LED Control bit
set
0
1
1
0
Pulse 1
Pulse 2
n/a
The LED will Breathe when the start trigger
is detected. When the stop trigger is
detected, it will “Pulse” a number of times
then return to its minimum brightness.
Release
Detected or
LEDControl
bit cleared
Touch Detected
or LED Control
bit set
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 5.30.
Release
Detected or
LEDControl
bit cleared
Touch Detected
or LED Control
bit set
1
1
Breathe
Revision 1.1 (08-05-09)
SMSC CAP1088
DATA5S8HEET
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