Datasheet

 2009-2012 Microchip Technology Inc. Preliminary DS41393B-page 29
AR1000 SERIES RESISTIVE TOUCH SCREEN CONTROLLER
8.0 CONFIGURATION REGISTERS
The Configuration registers allow application specific
customization of the controller. The default values have
been optimized for most applications and are
automatically used, unless you choose to change
them.
Unique sensors and/or product applications may
benefit from adjustment of Configuration registers.
8.1 Restoring Default Parameters
• AR1010/AR1020
The factory default settings for the Configuration
registers can be recovered by writing a value of 0xFF
to address 0x00 of the EEPROM, then cycling power.
• AR1011/AR1021
The factory default settings for the Configuration
registers can be recovered by writing a value of 0xFF
to addresses 0x01 and 0x29 of the EEPROM, then
cycling power.
Configuration registers are defined as an Offset value
from the Start address for the register group.
To read or write to a register, do the following:
• Issue the
REGISTER_START_ADDRESS_REQUEST com-
mand to obtain the Start address for the register
group.
• Calculate the desired register’s absolute address
by adding the register’s Offset value to Start
address for the register group.
• Issue the REGISTER_READ or REGISTER_WRITE
command, using the calculated register’s
absolute address.
Note: Although most registers can be
configured for a value ranging from 0 to
255, using a value outside the specified
range for the specific register may
negatively impact performance.
TABLE 8-1: CONFIGURATION REGISTERS
Register Name
Address
Offset
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
AR1010/
AR1020
Default
AR1011/
AR1021
Default
<Special Use> 0x00 <Non-Configurable> 0x58 0x58
<Special Use> 0x01 <Non-Configurable> 0x01 0x01
TouchThreshold 0x02 Value of: 0-255 0xC5 0xC5
SensitivityFilter 0x03 Value of: 0-255 0x04 0x04
SamplingFast 0x04 Value of: 1, 2, 4, 8, 16, 32, 64, 128 0x04 0x04
SamplingSlow 0x05 Value of: 1, 2, 4, 8, 16, 32, 64, 128 0x10 0x10
AccuracyFilterFast 0x06 Value of: 1-8 0x02 0x04
AccuracyFilterSlow 0x07 Value of: 1-8 0x08 0x08
SpeedThreshold 0x08 Value of: 0-255 0x04 0x04
<Special Use> 0x09 <Non-Configurable> 0x23 0x23
SleepDelay 0x0A Value of: 0-255 0x64 0x64
PenUpDelay 0x0B Value of: 0-255 0x80 0x80
TouchMode 0x0C PD2 PD1 PD0 PM1 PM0 PU2 PU1 PU0 0xB1 0xB1
TouchOptions 0x0D
— — — — — —48WCCE 0x00 0x00
CalibrationInset 0x0E 0x19 0x19
PenStateReportDelay 0x0F Value of: 0-40 0xC8 0xC8
<Special Use> 0x10 Value of: 0-255 0x03 0x03
TouchReportDelay 0x11 <Non-Configurable> 0x00 0x00
<Special Use> 0x12 Value of: 0-255 0x00 0x00
Warning: Use of invalid register values will yield
unpredictable results.