Azoteq IQ Switch - ProxSense Series Guide

IQS316 Design Guide
IQ Switch®- ProxSense®Series
Multi-channel Integrated Proximity Sensor with Micro-Processor Core
This design guide provides a description of the communication interface between the master and
the IQS316 controller. The Memory Map of the IQS316 is provided in this document, followed by a
description of each register and instruction. The IQS316 communicates in I2C or SPI mode, both
using a Memory Mapped structure. The last section of this document is dedicated to an example
implementation and provides example code.

Contents
IQS316 Design Guide .................................................................................................................................................. 1
1Memory Map ..................................................................................................................................................... 4
1.1 General Memory Map Structure ....................................................................................................................... 4
1.2 IQS316 Memory Map ........................................................................................................................................ 5
1.2.1 Device Information ....................................................................................................................................... 5
1.2.2 Device Specific Data...................................................................................................................................... 6
1.2.3 Proximity Status Bytes .................................................................................................................................. 6
1.2.4 Touch Status Bytes........................................................................................................................................ 6
1.2.5 Halt Bytes...................................................................................................................................................... 7
1.2.6 Active Bytes................................................................................................................................................... 7
1.2.7 Current Samples............................................................................................................................................ 7
1.2.8 Long-Term Averages and Thresholds............................................................................................................ 9
1.2.9 Device Settings............................................................................................................................................ 11
1.3 Memory Map Description................................................................................................................................ 18
1.3.1 Device Information ..................................................................................................................................... 18
1.3.2 Device Specific Data.................................................................................................................................... 18
1.3.3 Proximity Status Bytes ................................................................................................................................ 19
1.3.4 Touch Status Bytes...................................................................................................................................... 19
1.3.5 Halt Bytes.................................................................................................................................................... 19
1.3.6 Active Bytes................................................................................................................................................. 19
1.3.7 Current Samples.......................................................................................................................................... 19
1.3.8 Long-Term Averages & Touch/Prox Thresholds ......................................................................................... 20
1.3.9 Device Settings............................................................................................................................................ 21
2General Implementation hints ..........................................................................................................................29
2.1 Communication window.................................................................................................................................. 29
2.1.1 SPI Communication window ....................................................................................................................... 29
2.1.2 I2C Communication window........................................................................................................................ 29
2.2 Startup Procedure ........................................................................................................................................... 29
2.2.1 Individual Prox and Touch Thresholds ........................................................................................................ 30
2.2.2 Auto ATI Procedure..................................................................................................................................... 30
2.2.3 Post Setup ................................................................................................................................................... 30
2.3 General I2C Hints ............................................................................................................................................. 31
2.3.1 I2C Pull-up resistors ..................................................................................................................................... 31
2.3.2 MCLR........................................................................................................................................................... 31
2.3.3 Reset Device while using I2C ....................................................................................................................... 31
3Sample implementation....................................................................................................................................31
3.1 Overview.......................................................................................................................................................... 31
3.1.1 Communications: ........................................................................................................................................ 31
3.2 Functions ......................................................................................................................................................... 33
3.2.1 IQS316_Settings.......................................................................................................................................... 33
3.2.2 IQS316_Refresh_Data................................................................................................................................. 38
3.2.3 IQS316_Process_Data ................................................................................................................................. 39
3.2.4 Main Function (I2C and SPI) ........................................................................................................................ 40
3.2.5 Comms_init................................................................................................................................................. 41
3.2.6 IQS316_Read............................................................................................................................................... 41
3.2.7 IQS316_ReadCurrentAddress ..................................................................................................................... 43

3.2.8 IQS316_Write.............................................................................................................................................. 44
3.2.9 IQS316_End_Comms_Window ................................................................................................................... 45
3.2.10 Comms_Error.......................................................................................................................................... 46
3.2.11 I2C byte write .......................................................................................................................................... 46
3.2.12 Read with NACK...................................................................................................................................... 47
3.2.13 Read with ACK ........................................................................................................................................ 47
3.2.14 I2C START ................................................................................................................................................ 48
3.2.15 I2C STOP .................................................................................................................................................. 48
3.2.16 SPI Receive/Transmit.............................................................................................................................. 48
3.2.17 Constant Declarations ............................................................................................................................ 49

1 Memory Map
1.1 General Memory Map Structure
A general I2C and SPI Memory Map is defined so that all ProxSense®devices can use a standard
framework. The general mapping is shown below.
Table 1.1 IQS316 Memory Mapping
Address
Access
Size(Bytes)
Device Information
00H-0FH
R
16
Address
Access
Size(Bytes)
Device Specific Data
10H-30H
R
32
Address
Access
Size(Bytes)
Proximity Status Bytes
31H-34H
R
4
Address
Access
Size(Bytes)
Touch Status Bytes
35H-38H
R
4
Address
Access
Size(Bytes)
Halt Bytes
39H-
3CH
R
4
Address
Access
Size(Bytes)
Active Bytes (indicate cycle)
3DH-
41H
R
4
Address
Access
Size(Bytes)
Current Samples
42H-82H
R
64

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Address
Access
Size(Bytes)
LTAs
83H-
C3H
R/W
64
Address
Access
Size(Bytes)
Device Settings
C4h-
FDh
R/W
64
* Note „FE‟ and „FF‟ are reserved for other functions in communication.
1.2 IQS316 Memory Map
1.2.1 Device Information
Address
Product Number
00H
Bit
7
6
5
4
3
2
1
0
Access
Value
27 (Decimal)
R
Address
Version Number
01H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable
R

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1.2.2 Device Specific Data
Address
XY Info 1 (UI_FLAGS0)
10H
Bit
7
6
5
4
3
2
1
0
Access
Value
SHOW_RESET
MODE_INDICATOR
~
~
~
ATI_BUSY
RESEED_BUSY
NOISE
R
1.2.3 Proximity Status Bytes
Only the proximity status of the channels relating to the current group is available here.
Address
Proximity Status (Group dependant)
31H
Bit
7
6
5
4
3
2
1
0
Access
Name
If Group = 0
CH3
CH2
CH1
CH0
R
Name
If Group = 1
CH7
CH6
CH5
CH4
Name
If Group = 2
CH11
CH10
CH9
CH8
Name
If Group = 3
CH15
CH14
CH13
CH12
Name
If Group = 4
CH19
CH18
CH17
CH16
1.2.4 Touch Status Bytes
Only the touch status of the channels relating to the current group is available here.
Address
Touch Status (Group dependant)
35H
Bit
7
6
5
4
3
2
1
0
Access
Name
If Group = 0
~
~
~
~
R
Name
If Group = 1
CH7
CH6
CH5
CH4
Name
If Group = 2
CH11
CH10
CH9
CH8
Name
If Group = 3
CH15
CH14
CH13
CH12
Name
If Group = 4
CH19
CH18
CH17
CH16
*Note: This byte is not used for Group 0 (Prox Mode)

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1.2.5 Halt Bytes
Only the filter halt status of the channels relating to the current group is available here.
Address
Halt Status (Group dependant)
39H
Bit
7
6
5
4
3
2
1
0
Access
Name
If Group = 0
CH3
CH2
CH1
CH0
R
Name
If Group = 1
CH7
CH6
CH5
CH4
Name
If Group = 2
CH11
CH10
CH9
CH8
Name
If Group = 3
CH15
CH14
CH13
CH12
Name
If Group = 4
CH19
CH18
CH17
CH16
1.2.6 Active Bytes
The group number is given here.
Address
Group Number
3DH
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (0-4)
R
Note
Indicates which group‟s data is currently available
1.2.7 Current Samples
The Current Samples of the current group are available here.
Address
Current Sample CH0 / CH4 / CH8 / CH12 / CH16
42H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (HIGH byte)
R
Note
CH0 (Group0) / CH4 (Group1) / CH8 (Group2) /
CH12 (Group3) / CH16 (Group4)

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Address
Current Sample CH0 / CH4 / CH8 / CH12 / CH16
43H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW byte)
R
Note
CH0 (Group0) / CH4 (Group1) / CH8 (Group2) /
CH12 (Group3) / CH16 (Group4)
Address
Current Sample CH1 / CH5 / CH9 / CH13 / CH17
44H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (HIGH byte)
R
Note
CH1 (Group0) / CH5 (Group1) / CH9 (Group2) /
CH13 (Group3) / CH17 (Group4)
Address
Current Sample CH1 / CH5 / CH9 / CH13 / CH17
45H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW byte)
R
Note
CH1 (Group0) / CH5 (Group1) / CH9 (Group2) /
CH13 (Group3) / CH17 (Group4)
Address
Current Sample CH2 / CH6 / CH10 / CH14 / CH18
46H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (HIGH byte)
R
Note
CH2 (Group0) / CH6 (Group1) / CH10 (Group2) /
CH14 (Group3) / CH18 (Group4)

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Address
Current Sample CH2 / CH6 / CH10 / CH14 / CH18
47H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW byte)
R
Note
CH2 (Group0) / CH6 (Group1) / CH10 (Group2) /
CH14 (Group3) / CH18 (Group4)
Address
Current Sample CH3 / CH7 / CH11 / CH15 / CH19
48H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (HIGH byte)
R
Note
CH3 (Group0) / CH7 (Group1) / CH11 (Group2) /
CH15 (Group3) / CH19 (Group4)
Address
Current Sample CH3 / CH7 / CH11 / CH15 / CH19
49H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW byte)
R
Note
CH3 (Group0) / CH7 (Group1) / CH11 (Group2) /
CH15 (Group3) / CH19 (Group4)
1.2.8 Long-Term Averages and Thresholds
The Long-Term averages, and each individual channels thresholds, of the current group are
available here to read AND overwrite.
Address
Long-Term Average CH0 / CH4 / CH8 / CH12 / CH16
83H
Bit
7
6
5
4
3
2
1
0
Value
Touch Threshold
Prox Threshold
Variable (HIGH byte)
Access
Default
0
0
0
0
R/W
Note
CH0 (Group0) / CH4 (Group1) / CH8 (Group2) /
CH12 (Group3) / CH16 (Group4)

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Address
Long-Term Average CH0 / CH4 / CH8 / CH12 / CH16
84H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW byte)
R/W
Note
CH0 (Group0) / CH4 (Group1) / CH8 (Group2) /
CH12 (Group3) / CH16 (Group4)
Address
Long-Term Average CH1 / CH5 / CH9 / CH13 / CH17
85H
Bit
7
6
5
4
3
2
1
0
Value
Touch Threshold
Prox Threshold
Variable (HIGH byte)
Access
Default
0
0
0
0
R/W
Note
CH1 (Group0) / CH5 (Group1) / CH9 (Group2) /
CH13 (Group3) / CH17 (Group4)
Address
Long-Term Average CH1 / CH5 / CH9 / CH13 / CH17
86H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW byte)
R/W
Note
CH1 (Group0) / CH5 (Group1) / CH9 (Group2) /
CH13 (Group3) / CH17 (Group4)
Address
Long-Term Average CH2 / CH6 / CH10 / CH14 / CH18
87H
Bit
7
6
5
4
3
2
1
0
Value
Touch Threshold
Prox Threshold
Variable (HIGH byte)
Access
Default
0
0
0
0
R/W
Note
CH2 (Group0) / CH6 (Group1) / CH10 (Group2) /
CH14 (Group3) / CH18 (Group4)

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Address
Long-Term Average CH2 / CH6 / CH10 / CH14 / CH18
88H
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW byte)
R/W
Note
CH2 (Group0) / CH6 (Group1) / CH10 (Group2) /
CH14 (Group3) / CH18 (Group4)
Address
Long-Term Average CH3 / CH7 / CH11 / CH15 / CH19
89H
Bit
7
6
5
4
3
2
1
0
Value
Touch Threshold
Prox Threshold
Variable (HIGH byte)
Access
Default
0
0
0
0
R/W
Note
CH3 (Group0) / CH7 (Group1) / CH11 (Group2) /
CH15 (Group3) / CH19 (Group4)
Address
Long-Term Average CH3 / CH7 / CH11 / CH15 / CH19
8AH
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW byte)
R/W
Note
CH3 (Group0) / CH7 (Group1) / CH11 (Group2) /
CH15 (Group3) / CH19 (Group4)
1.2.9 Device Settings
An attempt is made so that the commonly used settings are situated closer to the top of the
memory block. Settings that are regarded as more „once-off‟ are placed further down.
Address
UI Settings 0 (UI_SETTINGS0)
C4H
Bit
7
6
5
4
3
2
1
0
Access
Name
RESEED
ATI_MODE
PROX
RANGE
TOUCH
RANGE
FORCE
PROX
MODE
FORCE
TOUCH
MODE
ND
0
R/W
Default
0
0
1
0
0
0
1
0

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Address
Power Settings (POWER_SETTINGS)
C5H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
SLEEP
MAIN_OSC
LP1
LP0
R/W
Default
~
~
~
~
0
0
0
0
Address
ProxSense®Module Settings 1 (PROX_SETTINGS_1)
C6H
Bit
7
6
5
4
3
2
1
0
Access
Name
CXVSS
ZC_EN
HALT1
HALT0
AUTO_
ATI
CXDIV2
CXDIV1
CXDIV0
R/W
Default
1
0
0
1
0
0
1
0
Address
ProxSense®Module Settings 2 (PROX_SETTINGS_2)
C7H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
SHIELD_
EN
STOP_
COMMS
ACK_
RESET
SKIP_
CONV
ACF_
DISABLE
LTN_
DISABLE
WDT_
DISABLE
R/W
Default
~
0
0
0
0
0
0Note 1
1
Note1: The LTN filter has a limitation: it is default ON, but it is recommended that this feature
be disabled by the user (setting the bit).
Address
ATI Multiplier C (ATI_MULT1)
C8H
Bit
7
6
5
4
3
2
1
0
Access
Name
If Group = 0
CH3
CH2
CH1
CH0
R/W
If Group = 1
CH7
CH6
CH5
CH4
If Group = 2
CH11
CH10
CH9
CH8
If Group = 3
CH15
CH14
CH13
CH12
If Group = 4
CH19
CH18
CH17
CH16
Default
0
0
0
0
0
0
0
0

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Address
ATI Multiplier I (ATI_MULT2)
C9H
Bit
7
6
5
4
3
2
1
0
Access
Name
CH3
CH2
CH1
CH0
If Group = 0
R/W
CH7
CH6
CH5
CH4
If Group = 1
CH11
CH10
CH9
CH8
If Group = 2
CH15
CH14
CH13
CH12
If Group = 3
CH19
CH18
CH17
CH16
If Group = 4
Default
0
0
0
0
~
~
~
~
Address
ATI Compensation Setting (ATI_C0)
CAH
Bit
7
6
5
4
3
2
1
0
Access
Value
If Group = 0
CH0
R/W
If Group = 1
CH4
If Group = 2
CH8
If Group = 3
CH12
If Group = 4
CH16
Address
ATI Compensation Setting (ATI_C1)
CBH
Bit
7
6
5
4
3
2
1
0
Access
Value
If Group = 0
CH1
R/W
If Group = 1
CH5
If Group = 2
CH9
If Group = 3
CH13
If Group = 4
CH17

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Address
ATI Compensation Setting (ATI_C2)
CCH
Bit
7
6
5
4
3
2
1
0
Access
Value
If Group = 0
CH2
R/W
If Group = 1
CH6
If Group = 2
CH10
If Group = 3
CH14
If Group = 4
CH18
Address
ATI Compensation Setting (ATI_C3)
CDH
Bit
7
6
5
4
3
2
1
0
Access
Value
If Group = 0
CH3
R/W
If Group = 1
CH7
If Group = 2
CH11
If Group = 3
CH15
If Group = 4
CH19
Address
Shield Settings (SHLD_SETTINGS)
CEH
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
~
SHLD2
SHLD1
SHLD0
R/W
Default
0
0
0
0
0
0
0
0
* Note this byte will be ignored if SHIELD_EN (PROX_SETTINGS_2<6>) is set (i.e. if
automated shield is selected).

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Address
Unused (keep 00H)
CFH
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
0
0
0
0
0
0
R/W
Default
~
~
0
0
0
0
0
0
Address
Cx Configuration (CX_CONFIG)
D0H
Bit
7
6
5
4
3
2
1
0
Access
Name
CX_GPIO_1
CX_GPIO_0
~
~
Prox Mode Group Selection (PM_CX_SELECT)
GROUP4
GROUP3
GROUP2
GROUP1
R/W
Default
0
0
~
~
1
1
1
1
Address
DEFAULT_COMMS_POINTER
D1H
Bit
7
6
5
4
3
2
1
0
Access
Default
10H (Beginning of Device Specific Data)
R/W
Address
Individual Channel Disable (CHAN_ACTIVE0)
D2H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH3
CH2
CH1
CH0
R/W
Default
~
~
~
~
0
0
1
1
*Note: Only group 0 and 1 are default on, this is because with more than 2 channels active,
the AC Filter isn‟t sampled at the optimal frequency, and is thus less effective.
Address
Individual Channel Disable (CHAN_ACTIVE1)
D3H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH7
CH6
CH5
CH4
R/W
Default
~
~
~
~
1
1
1
1

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Address
Individual Channel Disable (CHAN_ACTIVE2)
D4H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH11
CH10
CH9
CH8
R/W
Default
~
~
~
~
1
1
1
1
Address
Individual Channel Disable (CHAN_ACTIVE3)
D5H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH15
CH14
CH13
CH12
R/W
Default
~
~
~
~
1
1
1
1
Address
Individual Channel Disable (CHAN_ACTIVE4)
D6H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH19
CH18
CH17
CH16
R/W
Default
~
~
~
~
1
1
1
1
Address
Individual Channel Reseed (CHAN_RESEED0)
D7H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH3
CH2
CH1
CH0
R/W
Default
~
~
~
~
0
0
0
0
Address
Individual Channel Reseed (CHAN_RESEED1)
D8H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH7
CH6
CH5
CH4
R/W
Default
~
~
~
~
0
0
0
0

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Address
Individual Channel Reseed (CHAN_RESEED2)
D9H
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH11
CH10
CH9
CH8
R/W
Default
~
~
~
~
0
0
0
0
Address
Individual Channel Reseed (CHAN_RESEED3)
DAH
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH15
CH14
CH13
CH12
R/W
Default
~
~
~
~
0
0
0
0
Address
Individual Channel Reseed (CHAN_RESEED4)
DBH
Bit
7
6
5
4
3
2
1
0
Access
Name
~
~
~
~
CH19
CH18
CH17
CH16
R/W
Default
~
~
~
~
0
0
0
0
Address
Auto ATI Target
DCH
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (HIGH Byte)
R/W
Default
04H (giving a Target value of = 1024 decimal)
Address
Auto ATI Target
DDH
Bit
7
6
5
4
3
2
1
0
Access
Value
Variable (LOW Byte)
R/W
Default
00H (giving a Target value of = 1024 decimal)

IQ Switch®
ProxSense®Series
Copyright © Azoteq (Pty) Ltd 2013
IQS316 Design Guide
Page 18 of 54
All Rights Reserved.
Revision 0.04
December 2013
Address
I/O Port
DEH
Bit
7
6
5
4
3
2
1
0
Access
Name
GPIO_7
GPIO_6
GPIO_5
GPIO_4
GPIO_3
GPIO_2
GPIO_1
GPIO_0
R/W
I/O‟s can be read, or set/cleared here.
Address
I/O Tris
DFH
Bit
7
6
5
4
3
2
1
0
Access
Name
GPIO_7
GPIO_6
GPIO_5
GPIO_4
GPIO_3
GPIO_2
GPIO_1
GPIO_0
R/W
Default
1
1
1
1
1
1
1
1
NOTE: If the pins are used as Cx channels, they MUST be set to inputs in the TRIS register
1.3 Memory Map Description
1.3.1 Device Information
Product Number
The product number for the IQS316 is 27 (decimal).
Version Number
The version number of the device ROM can be read in this byte.
1.3.2 Device Specific Data
XY Info1 (UI_FLAGS0)
Bit 7: SHOW_RESET:This bit can be read to determine whether a reset occurred on
the device since the ACK_RESET bit has been set. The value of
SHOW_RESET can be set to „0‟ by writing a „1‟ in the ACK_RESET bit in the
PROX_SETTINGS_2 byte.
0 = No reset has occurred since last cleared
1 = Reset has occurred
Bit 6: MODE_INDICATOR:Indicates current mode of charging
0 = Currently in Prox Mode
1 = Currently in Touch Mode
Bit 5:3: Unused
Bit 2: ATI_BUSY:Status of automated ATI routine
0 = Auto ATI is not busy
1 = Auto ATI in progress
Bit 1: RESEED_BUSY:Global Channel Reseed Status

IQ Switch®
ProxSense®Series
Copyright © Azoteq (Pty) Ltd 2013
IQS316 Design Guide
Page 19 of 54
All Rights Reserved.
Revision 0.04
December 2013
0 = Reseed is not busy
1 = Reseed is currently taking place
Bit 0: NOISE:This bit indicates the presence of noise interference.
0 = Current cycle has not detected the presence of noise
1 = Current cycle has detected the presence of noise
1.3.3 Proximity Status Bytes
Proximity Status
The proximity status of the channels relating to the current group can be read here. The current
group can be determined by reading the Group Number register. The channels and group
numbers relate as shown in Table 1.2.
Table 1.2 Channel data available
Current Group Number
Channels available
0
CH0 / CH1 / CH2 / CH3
1
CH4 / CH5 / CH6 / CH7
2
CH8 / CH9 / CH10 / CH11
3
CH12 / CH13 / CH14 / CH15
4
CH16 / CH17 / CH18 / CH19
1.3.4 Touch Status Bytes
Touch Status
The touch status of the channels relating to the current group can be read here. The current group
can be determined by reading the Group Number register. The channels and group numbers
relate as shown in Table 1.2.
1.3.5 Halt Bytes
Halt Status
The halt status of the channels relating to the current group can be read here. The current group
can be determined by reading the Group Number register. The channels and group numbers
relate as shown in Table 1.2.
1.3.6 Active Bytes
Group Number
The group number that can be read in this byte indicates which group‟s data is currently
available. Group 0 is the Prox Mode group, and Group 1-4 are the Touch Mode groups.
1.3.7 Current Samples
The Current Samples for the current group can be read in their respective addresses. The
HIGH bytes and LOW bytes are found in consecutive addresses.

IQ Switch®
ProxSense®Series
Copyright © Azoteq (Pty) Ltd 2013
IQS316 Design Guide
Page 20 of 54
All Rights Reserved.
Revision 0.04
December 2013
1.3.8 Long-Term Averages & Touch/Prox Thresholds
The LTA values for the current group can be read in their respective addresses. The HIGH
bytes and LOW bytes are found in consecutive addresses.
The first four bits (high nibble) of each LTA HIGH Byte is the Prox and Touch Thresholds for
the respective channel. Care must be taken when overwriting a LTA that the required settings
are also included in the HIGH byte.
LTA HIGH Byte
Bit 7-6: Touch Threshold:The value of these two bits, together with the global Touch
Range bit determines the Touch Threshold, as shown in Table 1.3.
Bit 5-4: Prox Threshold: The value of these two bits, together with the Prox Range bit
determines the Prox Threshold, as shown in 0.
Bit 3-0: LTA<11:8>: The upper 4 bits of the LTA.
Table 1.3 Touch Threshold Values
Table 1.4 Prox Threshold Values
Prox Threshold <1:0>
PROX_RANGE = 0
PROX_RANGE = 1
Prox Threshold
00
2
8 (default)
01
3
16
10
4
20
11
6
30
LTA LOW Byte
Bit 7-0: LTA<7:0>: The lower byte of the LTA.
Touch Threshold <1:0>
TOUCH_RANGE = 0
TOUCH_RANGE = 1
Touch Threshold:
00
1/32 (default)
4/16
01
1/16
6/16
10
2/16
8/16
11
3/16
10/16