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  • 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