I2c Device Calibration Best | Kmdf Hid Minidriver For Touch

Implementing Best Practices for Touch Calibration in KMDF HID Minidrivers (I2C)

Author: Technical Systems Engineering Subject: Windows Driver Development / HID Minidrivers Complexity: Advanced

Registry-Based Storage: Store calibration constants (offsets and scale factors) in the Windows Registry under HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\TOUCH as CalibrationData. This allows the driver to load custom values without a recompile. kmdf hid minidriver for touch i2c device calibration best

Why KMDF?

• KMDF handles power management, PnP, and I/O queues, letting you focus on transport logic.
• It provides built-in support for I²C target operations (via WdfIoTargetSendReadSynchronously or SPB I/O requests).

Persistent Storage: Save these values to the device's EEPROM or the host's registry for the driver to apply on every report.  Common Issues & Solutions  SileadTouch.sys - GitHub Implementing Best Practices for Touch Calibration in KMDF

Conclusion

• The firmware cannot store calibration parameters.
• OEMs require per-device calibration applied before Windows receives touch input.
• The device uses non-standard coordinates (e.g., inverted axis, non-linear scaling).

: If the hardware reports coordinates that are inverted or shifted, you can often apply a "transform matrix" or specific calibration values via the registry keys associated with the HID device. Windows Built-in Calibration KMDF handles power management, PnP, and I/O queues,