Datasheet
8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
Revision 1.32 (01-05-12) 44 SMSC CAP1188
DATASHEET
Bit 2 - LED3_DN - Indicates that LED3 has finished its behavior after being actuated by the host.
Bit 1 - LED2_DN - Indicates that LED2 has finished its behavior after being actuated by the host.
Bit 0 - LED1_DN - Indicates that LED1 has finished its behavior after being actuated by the host.
5.3 Noise Flag Status Registers
The Noise Flag Status registers store status bits that are generated from the analog block if the
detected noise is above the operating region of the analog detector or the RF noise detector. These
bits indicate that the most recently received data from the sensor input is invalid and should not be
used for touch detection. So long as the bit is set for a particular channel, the delta count value is reset
to 00h and thus no touch is detected.
These bits are not sticky and will be cleared automatically if the analog block does not report a noise
error.
APPLICATION NOTE: If the MTP detection circuitry is enabled, these bits count as sensor inputs above the MTP
threshold (see Section 4.5.4, "Multiple Touch Pattern Detection") even if the corresponding
delta count is not. If the corresponding delta count also exceeds the MTP threshold, it is not
counted twice.
APPLICATION NOTE: Regardless of the state of the Noise Status bits, if low frequency noise is detected on a
sensor input, that sample will be discarded unless the DIS_ANA_NOISE bit is set. As well,
if RF noise is detected on a sensor input, that sample will be discarded unless the
DIS_RF_NOISE bit is set.
5.4 Sensor Input Delta Count Registers
Table 5.5 Noise Flag Status Registers
ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT
0Ah R
Noise Flag
Status
CS8_
NOISE
CS7_
NOISE
CS6_
NOISE
CS5_
NOISE
CS4_
NOISE
CS3_
NOISE
CS2_
NOISE
CS1_
NOISE
00h
Table 5.6 Sensor Input Delta Count Registers
ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT
10h R
Sensor Input 1
Delta Count
Sign 64 32 16 8 4 2 1 00h
11h R
Sensor Input 2
Delta Count
Sign 64 32 16 8 4 2 1 00h
12h R
Sensor Input 3
Delta Count
Sign 64 32 16 8 4 2 1 00h
13h R
Sensor Input 4
Delta Count
Sign 64 32 16 8 4 2 1 00h
14h R
Sensor Input 5
Delta Count
Sign 64 32 16 8 4 2 1 00h
15h R
Sensor Input 6
Delta Count
Sign 64 32 16 8 4 2 1 00h