AR1100 Datasheet, PDF (26/58 Pages) Microchip Technology – AR1100 Resistive USB and RS-232 Touch Screen Controller

AR1100 RESISTIVE USB AND RS-232 TOUCH SCREEN CONTROLLER
6.1 Register 0: RisetimeCapTimeout
(ADVANCED – DO NOT CHANGE)
The RisetimeCapTimeout value is used in the
proprietary algorithm associated with sensor
characteristics.
6.2 Register 1: RisetimeQuick
(ADVANCED – DO NOT CHANGE)
The RisetimeQuick value is used in the proprietary
algorithm associated with sensor characteristics.
6.3 Register 2: TouchThreshold
The TouchThreshold value sets the threshold for
detecting a touch condition. A larger value relaxes the
criteria for detecting a touch and a small value is more
demanding.
6.4 Register 3: SensitivityFilter
The SensitivityFilter value sets a criteria for touch
‘stability’. A larger value is more sensitive to a touch but
possibly less ‘stable’. A smaller value requires a
‘harder’ touch but provides a more stable position.
6.5 Register 4: SamplingFast
The SamplingFast register sets the level of touch
measurement sample averaging, when touch
movement is determined to be fast (reference
SpeedThreshold). A lower value will result in faster
reporting but may be more susceptible to noise in touch
positions. A higher value will reduce the report rate but
provide more immunity to random noise in the reported
touch positions.
6.6 Register 5: SamplingSlow
The SamplingFast register sets the level of touch
measurement sample averaging, when touch
movement is determined to be slow (reference
SpeedThreshold). A lower value will result in faster
reporting but may be more susceptible to noise in touch
positions. A higher value will reduce the report rate but
provide more immunity to random noise in the reported
touch positions.
6.7 Register 6: AccuracyFilterFast
The AccuracyFilterFast sets the level of touch
measurement accuracy enhancement used when the
touch movement is determined to be ‘fast’ (reference
SpeedThreshold). A lower value will increase touch
position resolution but may exhibit more noise in
reported touch positions. A higher value will decrease
touch position resolution but increase immunity to
noise in reported touch positions.
6.8 Register 7: AccuracyFilterSlow
The AccuracyFilterFast sets the level of touch
measurement accuracy enhancement used when the
touch movement is determined to be ‘slow’ (reference
SpeedThreshold). A lower value will increase touch
position resolution but may exhibit more noise in
reported touch positions. A higher value will decrease
touch position resolution but increase immunity to
noise in reported touch positions.
6.9 Register 8: SpeedThreshold
The SpeedThreshold value sets the threshold for touch
movement to be considered as ‘slow’ or ‘fast’. A lower
value reduces the touch movement speed that will be
considered ‘fast’. A higher value has the opposite
effect.
6.10 Register 9: DitherFilter
The DitherFilter value sets the threshold to prevent the
reported touch location from changing during what is
thought to be a stationary touch. The computed touch
position must change by an amount greater than Dith-
erFilter (either X or Y) before the reported position
changes.
6.11 Register 10: SleepDelay
The SleepDelay value sets the time interval (with no
touch or host communication) that will cause the
AR1100 to enter a low-power Sleep mode (UART
Communication mode only).
6.12 Register 11: PenUpDelay
The PenUpDelay sets the time required for a pen-up
event/condition before the controller will send a touch
report with a pen-up status – effectively debouncing
pen up. The delay timer resets if a pen-down condition
is detected before the timer expires. A lower value will
increase the responsiveness of the controller to pen up.
A higher value will decrease the responsiveness.
DS41606B-page 26
 2011 Microchip Technology Inc.