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 .
Most touch screens suffer from scaling, rotation, and translation offsets due to manufacturing variations. A 2D affine transformation solves this issue using a calibration matrix. The mathematical mapping from raw coordinates to calibrated coordinates is represented by:
Some drivers read a .ini or .bin file from System32\Drivers , though this is less common in modern KMDF designs. 6. Testing and Validation kmdf hid minidriver for touch i2c device calibration
// Define the HidCalibrate callback routine VOID HidCalibrate( _In_ WDFDEVICE Device, _In_ PCALIBRATION_DATA CalibrationData )
switch (IoControlCode)
Raw data coming out of an I2C touch controller rarely matches the logical screen pixels perfectly. Micro-alignments, manufacturing tolerances, and display orientations require a software-level transformation matrix. The 3-Point Calibration Formula
void EvtIoDeviceControl( WDFQUEUE Queue, WDFREQUEST Request, size_t OutputBufferLength, size_t InputBufferLength, ULONG IoControlCode) Your KMDF driver alone cannot perform calibration; it
: Drivers must often use map() functions to scale raw sensor data to the screen's dimensions.
Xcalibrated=A⋅Xraw+B⋅Yraw+CGcap X sub c a l i b r a t e d end-sub equals the fraction with numerator cap A center dot cap X sub r a w end-sub plus cap B center dot cap Y sub r a w end-sub plus cap C and denominator cap G end-fraction A 2D affine transformation solves this issue using
Calibration must survive reboots. KMDF offers the registry as a persistent store.
// Apply affine transformation: X' = a*X + b // Include deadzone handling, edge rejection // Clamp to valid screen bounds