8 Channel Capacitive Touch Sensor with 2 LED Drivers
Datasheet
Bit 3 - CS4_STBY - Controls whether the CS4 channel is active in Standby.
Bit 2 - CS3_STBY - Controls whether the CS3 channel is active in Standby.
Bit 1 - CS2_STBY - Controls whether the CS2 channel is active in Standby.
Bit 0 - CS1_STBY - Controls whether the CS1 channel is active in Standby.
5.21
Standby Configuration Register
Table 5.36 Standby Configuration Register
ADDR
R/W
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
Standby
Configuration
AVG_
SUM
STBY_SAMP_
TIME[1:0]
STBY_CY_TIME
[1:0]
41h
STBY_AVG[2:0]
39h
The Standby Configuration register controls averaging and cycle time for those sensor inputs that are
active in Standby. This register is useful for detecting proximity on a small number of sensor inputs as
it allows the user to change averaging and sample times on a limited number of sensor inputs and still
maintain normal functionality in the fully active state.
Bit 7 - AVG_SUM - Determines whether the active sensor inputs will average the programmed number
of samples or whether they will accumulate for the programmed number of samples.
‘0’ - (default) - The active sensor input delta count values will be based on the average of the
programmed number of samples when compared against the threshold.
‘1’ - The active sensor input delta count values will be based on the summation of the programmed
number of samples when compared against the threshold. This bit should only be set when
performing proximity detection as a physical touch will overflow the delta count registers and may
result in false readings.
Bits 6 - 4 - STBY_AVG[2:0] - Determines the number of samples that are taken for all active channels
during the sensor cycle as shown in Table 5.37. All samples are taken consecutively on the same
channel before the next channel is sampled and the result is averaged over the number of samples
measured before updating the measured results.
Table 5.37 STBY_AVG Bit Decode
STBY_AVG[2:0]
NUMBER OF SAMPLES TAKEN
2
1
0
PER MEASUREMENT
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
2
4
8 (default)
16
32
64
128
SMSC CAP1128
Revision 1.32 (01-05-12)
DATA6S1HEET
SMSC [ SMSC CORPORATION ]
