3 Channel Capacitive Touch Sensor with 3 LED Drivers
Datasheet
5.10
Averaging and Sampling Configuration Register
Table 5.17 Averaging and Sampling Configuration Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
Averaging and
Sampling
Config
CYCLE_TIME
[1:0]
24h
R/W
AVG[2:0]
SAMP_TIME[1:0]
39h
The Averaging and Sampling Configuration register controls the number of samples taken and the total
sensor input cycle time for all active sensor inputs while the device is functioning in Active state.
Bits 6 - 4 - AVG[2:0] - Determines the number of samples that are taken for all active channels during
the sensor cycle as shown in Table 5.18. 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.
For example, if CS1, CS2, and CS3 are sampled during the sensor cycle, and the AVG[2:0] bits are
set to take 4 samples per channel, then the full sensor cycle will be: CS1, CS1, CS1, CS1, CS2, CS2,
CS2, CS2, CS3, CS3, CS3, CS3.
Table 5.18 AVG Bit Decode
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
Bits 3 - 2 - SAMP_TIME[1:0] - Determines the time to take a single sample as shown in Table 5.19.
Table 5.19 SAMP_TIME Bit Decode
SAMP_TIME[1:0]
1
0
SAMPLE TIME
0
0
1
0
1
0
320us
640us
1.28ms (default)
Revision 1.32 (01-05-12)
SMSC CAP1133
DATA3S6HEET
SMSC [ SMSC CORPORATION ]
