XPT2046.h

// https://github.com/median-dispersion/XPT2046-Driver/blob/main/XPT2046.h
 
#ifndef _XPT2046_H
#define _XPT2046_H
 
#include "Arduino.h"
#include "SPI.h"
 
class XPT2046 {
 
  //-----------------------------------------------------------------------------------------------
  // Public
 
  public:
 
    // Point structure
    struct Point {
 
      uint16_t x;
      uint16_t y;
 
    };
 
    // Calibration structure
    struct Calibration {
 
      float A;
      float B;
      float C;
      float D;
      float E;
      float F;
      uint16_t width;
      uint16_t height;
 
    };
 
    XPT2046(uint8_t csPin, uint8_t irqPin);                 // Constructor
 
    void  begin();                                          // Initialize everything
    void  setSampleCount(uint8_t samples);                  // Set the number of samples to average over
    void  setRotation(uint8_t rotation);                    // Set the rotation
    void  setCalibration(Calibration calibration);          // Set the calibration matrix
    void  setDebounceTimeout(uint16_t timeoutMilliseconds); // Set the debounce timeout in milliseconds
    bool  touched();                                        // Returns if the touchscreen is being touched
    bool  released();                                       // Returns if a touch event has been released
    Point getTouchPosition();                               // Return the touch position
 
  //-----------------------------------------------------------------------------------------------
  // Private
 
  private:
 
    uint8_t     _csPin;                       // CS pin
    uint8_t     _irqPin;                      // IRQ pin
    SPIClass    *_spi;                        // SPI pointer
    uint8_t     _sampleCount;                 // Current number of samples to average over
    uint8_t     _rotation;                    // Current rotation
    Calibration _calibration;                 // Calibration matrix
    bool        _calibrated;                  // Flag for checking if calibration was set
    uint16_t    _debounceTimeoutMilliseconds; // Debounce timeout in milliseconds
    uint64_t    _lastTouchMilliseconds;       // Last touch event time in milliseconds
    bool        _released;                    // Flag for if a touch event has been released
 
    uint16_t _readValue(uint8_t command);        // Read a value from the XPT2046 via SPI
    Point    _averageSamples(Point *samples);    // Average samples
    Point    _readTouchPosition();               // Read the touch position via SPI
    Point    _rotatePosition(Point position);    // Rotate a position
    Point    _calibratePosition(Point position); // Map the position based on the calibration matrix
    bool     _touched();                         // Return the touch status and resets the released flag
 
};
 
#endif