Kmdf Hid Minidriver For Touch I2c Device Calibration Instant

Calibration for KMDF HID minidrivers (commonly used for Silead and other I2C touchscreens) typically happens through firmware parameters in the Windows Registry or the .inf installation file rather than a graphical tool.

If your touch input is inverted, offset, or restricted to a small area, follow the steps below to correct the calibration. 1. Locate the Driver in Device Manager

Before making changes, verify you have the correct driver installed. Press Win + X and select Device Manager. Expand Human Interface Devices. Look for KMDF HID Minidriver for Touch I2C Device.

Right-click it, select Properties, and go to the Details tab.

Select Hardware Ids from the dropdown. Note the ID (e.g., ACPI\VEN_MSSL&DEV_1680). 2. Identify and Modify Registry Parameters

Most I2C touch minidrivers read calibration data from a specific registry key when the driver starts. Open Registry Editor (regedit.exe).

Navigate to:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\ACPI\\\Device Parameters

Look for the following keys (they may vary by manufacturer):

Touch0 to TouchX: These often contain hex values for X/Y limits. SwapXY: Set to 1 to swap axes; 0 to keep them. kmdf hid minidriver for touch i2c device calibration

InvertX / InvertY: Set to 1 to flip the direction of movement.

💡 Tip: If these keys are missing, check your driver's .inf file in the original driver folder. It usually lists the exact names of the parameters it uses. 3. Apply a Calibration Firmware File

Many Silead-based touchscreens require a specific firmware file (e.g., SileadTouch.fw) placed in the Windows Drivers folder to map the digitizer correctly.

Ensure the firmware file is in C:\Windows\System32\drivers\.

If the touch is still inaccurate, you may need a firmware file specific to your tablet model rather than just a generic driver.

Community-sourced firmware repositories like the gsl-firmware GitHub often provide the correct .fw files for various budget tablets. 4. Use the Built-in Windows Tool

If the hardware-level calibration (Registry/Firmware) is close but not perfect, use the Windows software-level calibration.

Search for "Calibrate the screen for pen or touch input" in the Start menu. Calibration for KMDF HID minidrivers (commonly used for

Click Calibrate... and follow the on-screen crosshair prompts.

Warning: This only fixes slight offsets. If your touch is inverted or mirrored, you must fix the Registry or Firmware first. Troubleshooting Common Issues Primary Fix Touch is inverted Change InvertX or InvertY in Registry. X and Y are swapped Change SwapXY in Registry. Touch only works in a small box

Update the SileadTouch.fw file or correct the MaxX / MaxY values in Registry. No touch response

Check for a yellow exclamation mark in Device Manager and reinstall the driver. If you'd like to proceed, could you tell me:

What is the exact Hardware ID of the device? (found in Device Manager) What is the brand and model of the tablet/laptop? Is the touch inverted, offset, or completely unresponsive? Touchscreen Not Working Properly Windows Only - Hi10 Pro

The Calibration-Specific Extension: IOCTL Interface

To allow a user-mode calibration tool to interact with your driver, you must provide a private IOCTL. This is how the calibration GUI collects raw points and sends back coefficients.

Define a custom IOCTL in your header:

#define IOCTL_TOUCH_CALIBRATE_SET_COEFFS \ CTL_CODE(FILE_DEVICE_UNKNOWN, 0x800, METHOD_BUFFERED, FILE_ANY_ACCESS)

#define IOCTL_TOUCH_CALIBRATE_GET_RAW CTL_CODE(FILE_DEVICE_UNKNOWN, 0x801, METHOD_BUFFERED, FILE_ANY_ACCESS) Part 6: User-Mode Calibration Application – The Companion

In your KMDF driver, implement a EvtIoDeviceControl callback:

void EvtIoDeviceControl(
    WDFQUEUE Queue,
    WDFREQUEST Request,
    size_t OutputBufferLength,
    size_t InputBufferLength,
    ULONG IoControlCode)
switch(IoControlCode)
case IOCTL_TOUCH_CALIBRATE_SET_COEFFS:
            // Lock mutex, copy coefficients into device context, apply to next touch
            // Store in registry via WdfRegistry
            break;
        case IOCTL_TOUCH_CALIBRATE_GET_RAW:
            // Temporarily bypass calibration, read raw I2C registers, return
            break;

Part 6: User-Mode Calibration Application – The Companion Tool

Your KMDF driver alone cannot perform calibration; it only applies it. A user-mode application must guide the user, collect points, compute coefficients, and call DeviceIoControl.

High-level flow of the calibration tool:

Display targets: Show five crosshairs (center, four corners).
Collect raw points: For each target, call IOCTL_TOUCH_CALIBRATE_GET_RAW and record the I2C-reported coordinates.
Compute mapping: Solve the least-squares transformation matrix.
Send coefficients: Call IOCTL_TOUCH_CALIBRATE_SET_COEFFS.
Verify: Ask user to touch test points and validate.

This application must run with administrative privileges, as it modifies kernel-mode driver state.

5.2 Sequence to Retrieve Factory Calibration

Reset device (I²C write to register 0x01, value 0x01)
Wait 50ms
Read 16 bytes from register 0x80 (calibration table)
Store in registry for subsequent boots

Kmdf Hid Minidriver For Touch I2c Device Calibration Instant

The Calibration-Specific Extension: IOCTL Interface

Part 6: User-Mode Calibration Application – The Companion Tool

5.2 Sequence to Retrieve Factory Calibration

Further Reading & Resources