xpt2046.h

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#ifndef _XPT2046_H_
#define _XPT2046_H_

#define XPT2046_SAMPLES 8 /* number of samples to take */
#define XPT2046_DEBOUNCE 5 /* Debound value in mS */
#define XPT2046_EVENTS 10 /* Number of queued touch events */

#define XPT2046_READ_Y  0x91    /* Read Y position*/
#define XPT2046_READ_Z1 0xb1    /* Read Z1 */
#define XPT2046_READ_Z2 0xc1    /* read Z2 */
#define XPT2046_READ_X  0xd1    /* Read X position */


typedef struct xpt2046_win
{
    int xmin;
    int ymin;
    int xmax;
    int ymax;
} xpt2046_win_t;

typedef struct _xpt2046 
{
    // touch debounce state machine
    int state;  // Debounce state machine
    int ms;     // Debounce 1mS timer

    // rotation of touch screen
    int rotation;

    // raw uncorrected values
    xpt2046_win_t raw;

    // map calibration to this range
    xpt2046_win_t map;

    // touch input queue
    int ind;    // touch events
    int head;   // head of touch event queue
    int tail;   // tail of touch event queue
    uint16_t XQ[XPT2046_EVENTS+1];  // Debounced X result
    uint16_t YQ[XPT2046_EVENTS+1];  // Debounced Y result
} xpt2046_t;

typedef struct _sdev {
    uint16_t min,max;
    float mean, sdev;
} sdev_t;

/* xpt2046.c */
MEMSPACE void XPT2046_spi_init ( void );
MEMSPACE void XPT2046_key_flush ( void );
uint16_t XPT2046_read ( uint8_t cmd );
int XPT2046_xy_raw ( uint16_t *X , uint16_t *Y );
MEMSPACE int XPT2046_xy_filtered ( uint16_t *X , uint16_t *Y );
MEMSPACE int nearest_run ( int *v , int size , int minsamples , int *count );
MEMSPACE int XPT2046_xy_filtered ( uint16_t *X , uint16_t *Y );
MEMSPACE int XPT2046_xy_filtered_test ( uint16_t *X , uint16_t *Y );
MEMSPACE void XPT2046_task ( void );
MEMSPACE int XPT2046_key ( uint16_t *X , uint16_t *Y );
MEMSPACE int sdev ( uint16_t *samples , int size , sdev_t *Z );

#endif // _XPT2046_H_