Touch.h

00001 /******************************************************************
00002  *****                                                        *****
00003  *****  Name: Touch.h                                         *****
00004  *****  Ver.: 1.0                                             *****
00005  *****  Date: 04/01/2013                                      *****
00006  *****  Auth: Frank Vannieuwkerke                             *****
00007  *****        Erik Olieman                                    *****
00008  *****  Func: Touch driver for use with ADS7843               *****
00009  *****                                                        *****
00010  ******************************************************************/
00011 
00012 #ifndef MBED_Touch_H
00013 #define MBED_Touch_H
00014 
00015 #include "TFT.h"
00016 #include "mbed.h"
00017 
00018     typedef struct
00019     {
00020        int x;
00021        int y;
00022     } Coordinate;
00023 
00024     typedef struct
00025     {
00026     int         An,
00027                 Bn,
00028                 Cn,
00029                 Dn,
00030                 En,
00031                 Fn,
00032                 Divider ;
00033     } Matrix;
00034 
00035 class TouchScreenADS7843 {
00036 public:
00037     Coordinate  display;
00038     Coordinate  screen;
00039 
00040     /*
00041     * Create a Touchscreen object connected to SPI and two pins.
00042     *
00043     * @param mosi,miso,sclk SPI
00044     * @param cs pin connected to CS of ADS7843
00045     * @param irq pin connected to IRQ of ADS7843
00046     * @param pointer to SPI_TFT constructor
00047     *
00048     */
00049     TouchScreenADS7843(PinName tp_mosi, PinName tp_miso, PinName tp_sclk, PinName tp_cs, PinName tp_irq, TFT *_LCD);
00050 
00051     /*
00052     * Draw a 2 by 2 dot on the LCD screen.
00053     *
00054     * @param x (horizontal position)
00055     * @param y (vertical position)
00056     * @param color (16 bit pixel color)
00057     *
00058     */
00059     void TP_DrawPoint(unsigned int Xpos,unsigned int Ypos,unsigned int color);
00060     
00061     /*
00062     * Obtain averaged data from ADS7846.
00063     * does 9 consecutive reads and only stores averaged data
00064     * when the 9 points are within the treshold limits.
00065     *
00066     * @param screenPTR (pointer to store data)
00067     * @returns 1 on success
00068     * @returns 0 on failure
00069     *
00070     * If called with screenPTR = NULL - 'screen' variable is used, otherwise (parameter) is used.
00071     *
00072     */
00073     unsigned char Read_Ads7843(Coordinate * screenPtr = NULL);
00074 
00075     /*
00076     * Calibrate the touch panel.
00077     * Three crosshairs are drawn and need to be touched in sequence.  
00078     * A calibration matrix is set accordingly.
00079     *
00080     */
00081     void TouchPanel_Calibrate(void);
00082     
00083     /*
00084     * Obtain real x,y coordinates.
00085     * The x,y coordinates are calculated using the calibration matrix.
00086     *
00087     */
00088     unsigned char getDisplayPoint(void);
00089 
00090     /*
00091     * Read touchpanel screensample and matrix values.
00092     * 
00093     * In your code, create 2 structures using Matrix and screenPtr
00094     * and call this function with these structures.
00095     * the calibration values are returned into these structures.
00096     * Example:
00097     * Matrix matrix;
00098     * Coordinate ScreenSample[3];
00099     * GetCalibration(&matrix, &ScreenSample[0]);
00100     */
00101     void GetCalibration(Matrix * matrixPtr, Coordinate * screenPtr);
00102 
00103     /*
00104     * Set touchpanel calibration using screensample and matrix values.
00105     * 
00106     * In your code, create 2 structures based on Matrix and screenPtr,
00107     * copy saved calibration values into these structures
00108     * and call this function with these structures.
00109     * Example:
00110     * Matrix matrix;
00111     * Coordinate ScreenSample[3];
00112     * <pseudocode> load matrix with values from external storage (eg eeprom).
00113     * <pseudocode> load ScreenSample with values from external storage (eg eeprom).
00114     * SetCalibration(&matrix, &ScreenSample[0]);
00115     */
00116     void SetCalibration(Matrix * matrixPtr, Coordinate * screenPtr);
00117 
00118     TFT    *LCD;
00119     SPI        _tp_spi;
00120     DigitalOut _tp_cs;
00121     DigitalIn  _tp_irq;
00122 
00123 protected:
00124 
00125     #define    SPI_RD_DELAY    1
00126     #define    CHX             0xd0    // 12 bit mode
00127     #define    CHY             0x90
00128 
00129     Coordinate DisplaySample[3];
00130     Coordinate ScreenSample[3];
00131     Matrix matrix;
00132 
00133     /*
00134     * Obtain raw x,y data from ADS7846
00135     *
00136     * @param pointer to raw x and y coordinates (pointer to store data)
00137     * @returns x (horizontal position)
00138     * @returns y (vertical position)
00139     *
00140     */
00141     void TP_GetAdXY(int *x,int *y);
00142     
00143     /*
00144     * Obtain raw single channel data from ADS7846 (Called by TP_GetADXY)
00145     *
00146     * @param channel to be read (CHX or CHY)
00147     * @returns raw scaled down value (return value range must be between 0 and 1024)
00148     *
00149     */
00150     int Read_XY(unsigned char XY);
00151     
00152     /*
00153     * Draw a calibration crosshair on the LCD screen
00154     *
00155     * @param x (horizontal position)
00156     * @param y (vertical position)
00157     *
00158     */
00159     void DrawCross(unsigned int Xpos,unsigned int Ypos);
00160     
00161     /*
00162     * Set the calibration matrix
00163     *
00164     * @param displayPTR (pointer to display data)
00165     * @param screenPTR  (pointer to screen data)
00166     * @param matrixPTR  (pointer to calibration matrix)
00167     *
00168     * @returns 0 when matrix.divider != 0
00169     * @returns 1 when matrix.divider = 0
00170     *
00171     */
00172     unsigned char setCalibrationMatrix( Coordinate * displayPtr,Coordinate * screenPtr,Matrix * matrixPtr);
00173 
00174 };
00175 #endif