TSC2046.h

00001 
00002 #ifndef TSC2046_H
00003 #define TSC2046_H
00004 
00005 #include "TouchPanel.h"
00006 
00007 #define TSC2046_NUM_CALIB_POINTS (3)
00008 
00009 /**
00010  * Texas Instruments Touch Screen Controller (TSC2046).
00011  */
00012 class TSC2046 : public TouchPanel {
00013 public:
00014 
00015 
00016     /**
00017      * Constructor
00018      *
00019      * @param mosi SPI MOSI pin
00020      * @param miso SPI MISO pin
00021      * @param sck SPI SCK pin
00022      * @param cs chip-select pin
00023      */
00024     TSC2046(PinName mosi, PinName miso, PinName sck, PinName cs);
00025 
00026     virtual bool init(uint16_t width, uint16_t height);
00027 
00028     virtual bool read(touchCoordinate_t &coord);
00029     virtual bool calibrateStart();
00030     virtual bool getNextCalibratePoint(uint16_t* x, uint16_t* y);
00031     virtual bool waitForCalibratePoint(bool* morePoints, uint32_t timeout);
00032 
00033     /**
00034      * Calibrate the touch panel with already gathered calibration values.
00035      * The list with calibration points must at one point have been retrieved
00036      * by calling getCalibrationValues;
00037      *
00038      * @param values list with calibration values
00039      * @param numValues the size of the list must match the number of
00040      * calibration points needed for this touch panel (TSC2046_NUM_CALIB_POINTS)
00041      *
00042      * @return true if the request was successful; otherwise false
00043      */
00044     bool calibrate(touchCoordinate_t* values, int numValues);
00045 
00046     /**
00047      * Get calibration values for the calibration points used by this touch
00048      * panel. This method may only be called after a successful calibration
00049      * has been performed.
00050      *
00051      * The list with values can be written to persistent storage and used
00052      * to calibrate the display without involving the user.
00053      *
00054      * @param values calibration values will be written to this list
00055      * @param numValues the size of the list must match the number of
00056      * calibration points needed for this touch panel (TSC2046_NUM_CALIB_POINTS)
00057      *
00058      * @return true if the request was successful; otherwise false
00059      */
00060     bool getCalibrationValues(touchCoordinate_t* values, int numValues);
00061 
00062 
00063 private:
00064 
00065     typedef struct {
00066         int64_t x;
00067         int64_t y;
00068     } calibPoint_t;
00069 
00070     typedef struct {
00071         int64_t An;
00072         int64_t Bn;
00073         int64_t Cn;
00074         int64_t Dn;
00075         int64_t En;
00076         int64_t Fn;
00077         int64_t Divider;
00078     } calibMatrix_t;
00079 
00080     SPI _spi;
00081     DigitalOut _cs;
00082     bool _calibrated;
00083     bool _initialized;
00084     calibMatrix_t _calibMatrix;
00085 
00086     uint16_t _width;
00087     uint16_t _height;
00088     int _calibPoint;
00089     int _insetPx;
00090 
00091     touchCoordinate_t _calibrateValues[TSC2046_NUM_CALIB_POINTS][2];
00092 
00093     void readAndFilter(touchCoordinate_t &coord);
00094     int32_t getFilteredValue(int cmd);
00095     uint16_t spiTransfer(uint8_t cmd);
00096 
00097     void calibrate(touchCoordinate_t &ref1,
00098             touchCoordinate_t &ref2,
00099             touchCoordinate_t &ref3,
00100             touchCoordinate_t &scr1,
00101             touchCoordinate_t &scr2,
00102             touchCoordinate_t &scr3);
00103 
00104     void getCalibratePoint(int pointNum, int32_t* x, int32_t *y);
00105     int waitForTouch(int32_t* x, int32_t* y, uint32_t timeout);
00106 
00107 
00108 
00109     int setCalibrationMatrix( calibPoint_t * displayPtr,
00110             calibPoint_t * screenPtr,
00111             calibMatrix_t * matrixPtr);
00112     int getDisplayPoint( calibPoint_t * displayPtr,
00113             calibPoint_t * screenPtr,
00114             calibMatrix_t * matrixPtr );
00115 
00116 
00117 
00118 };
00119 
00120 #endif