Datasheet

8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
Revision 1.32 (01-05-12) 52 SMSC CAP1188
DATASHEET
5.10 Averaging and Sampling Configuration Register
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.
1 0 0 1 350ms
1 0 1 0 385ms
1 0 1 1 420ms
1 1 0 0 455ms
1 1 0 1 490ms
1 1 1 0 525ms
1 1 1 1 560ms
Table 5.17 Averaging and Sampling Configuration Register
ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT
24h R/W
Averaging and
Sampling
Config
AVG[2:0] SAMP_TIME[1:0]
CYCLE_TIME
[1:0]
39h
Table 5.18 AVG Bit Decode
AVG[2:0]
NUMBER OF SAMPLES TAKEN
PER MEASUREMENT2 1 0
0 0 0 1
0 0 1 2
0 1 0 4
0 1 1 8 (default)
1 0 0 16
Table 5.16 M_PRESS Bit Decode (continued)
M_PRESS[3:0]
M_PRESS SETTINGS3 2 1 0