Touch (UCB1400)

This describes the touch-driver for the UCB1400-codec found on the Trizeps-module.

Registry Keys

[HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\TOUCH]

[HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\TOUCH]

Key

Type

Description

MaxSigma

DWORD

Maximum deviation. Higher deviation will invalidate the read touch-samples. If using noisy displays, it might help to increase this value.

InitSamples

DWORD

How many samples to ignore after touch-press.

PressureL

DWORD

Low pressure (0..65536), Default=12. Value at which touch-pen up is detected. (UCB1400-Codec)

PressureH

DWORD

High pressure (0..65536), Default=31. Value at which touch-pen down is detected. (UCB1400-Codec)

WolfsonPressureH

DWORD

Pressure at which a touch-pen down is detected. Default: 260. Higher-values = More sensitive.

ArraySize

DWORD

Number of samples to take to determine average value.

SyncWithHsync

DWORD

Set to 0. Option to synchronize measurement with HSync of display.

VRefBypass

DWORD

Set to 0. Use to enable external reference-voltage.

InhibitIdle

DWORD

Inhibit idle, if touch is pressed. If the touch is sensitive against change of current consumption, setting this might help

SampleDelay

DWORD

Number of micro-seconds to wait after each sample

OldScale

DWORD

Set to 0. Used to scale touch-values, like it was done on the older version of this driver.

SampleTimer

DWORD

Sample-Frequency (Trizeps2+3 only): Expressed in number of system-ticks (3686400 Hz). Trizeps4+5: in us

DisableFilter

DWORD

Disable ADC filter if set to 1

REG78h

DWORD

Sets AC97-Register 0x78. Set to (0x6900 | div). Codec uses a 68k Pull up and a 1,8V threshold value. div = 68k / (((3,3V/1,8V)*Rtouch)-Rtouch) Touch (pen-down) resistance -> div value For 2,5kOhm -> div = 32.64 ( Use Maximum value of 31 !). For 5kOhm -> div = 16 For 10kOhm -> div = 8 (only Wolfson Codec)

See Also

Connect a 4-wire Touch to a Trizeps,
Connect a 5-Wire Touch Panel to the Trizeps 4-wire Touch Controller