Kmdf Hid Minidriver For Touch I2c Device Calibration Best [top] Jun 2026

Add calibration parameters to device context. Implement IOCTL or Feature Report set/get handlers.

: Multiplies coordinate targets to match the geometric direction of the display matrix. 2. Using the In-Box Windows Calibration Engine

typedef struct _CALIBRATION_DATA LONG XOffset; LONG YOffset; LONG XScale; // Fixed-point (e.g., 1.0 = 0x10000) LONG YScale; BOOLEAN SwapXY; BOOLEAN InvertX; BOOLEAN InvertY; CALIBRATION_DATA;

There are two schools of thought on where to apply the math: kmdf hid minidriver for touch i2c device calibration best

What (3-point, 5-point, etc.) does your hardware vendor recommend?

For many KMDF HID minidrivers, calibration is handled via registry keys rather than hard-coded values. You can often correct persistent offsets by injecting standard values into the Windows registry: Toradex Community HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\TOUCH CalibrationData

The term "calibration" in the keyword points to the most common pain point. Calibration ensures that the coordinates reported by the touchscreen when you press a physical point correspond exactly to the correct position on the display. Add calibration parameters to device context

However, many touch controllers require vendor-specific initialization, custom calibration routines, or non-standard register access—capabilities not fully covered by the generic in-box HIDI2C.sys driver. This is where a enters.

The user-mode calibration tool (e.g., a simple Win32 app) will:

If the hardware firmware lacks native non-volatile memory (NVRAM) or processing capability, the KMDF minidriver must intercept raw coordinate data ( You can often correct persistent offsets by injecting

Disable "Allow the computer to turn off this device to save power" in the I2C HID Device properties within Device Manager. CHUWI | Official Forum Technical Resources SileadTouch.sys - GitHub

, the touchscreen device is expected to report coordinates through a HID Report Descriptor . Calibration issues typically arise from: Microsoft Learn Resolution Mismatch: