Touchlib.h

00001 /* mbed TouchScreen ADS7846 library. 
00002 
00003     Copyright (c) 2011 NXP 3803 
00004  
00005     Permission is hereby granted, free of charge, to any person obtaining a copy
00006     of this software and associated documentation files (the "Software"), to deal
00007     in the Software without restriction, including without limitation the rights
00008     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009     copies of the Software, and to permit persons to whom the Software is
00010     furnished to do so, subject to the following conditions:
00011  
00012     The above copyright notice and this permission notice shall be included in
00013     all copies or substantial portions of the Software.
00014  
00015     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021     THE SOFTWARE.
00022 */
00023 
00024 #ifndef __TOOUCH_H
00025 #define __TOOUCH_H
00026 
00027 #include "mbed.h"
00028 #include "calibrate.h"
00029 
00030 /* Define per la compilazione del codice di gestione del PENIRQ */
00031 #define SW_PENIRQ
00032 /* */
00033 #define cTS_STARTBIT    0x80
00034 #define cTS_MODE    0x00
00035 #define cTS_SERDFR    0x00    /* SER/DFR =1 -> 0x04, */
00036 #define cTS_PWRUP    0x03    /* Device is powered ON, PENIRQ OFF */
00037 #define cTS_PWRDWN    0x00    /* Device is powered OFF, PENIRQ ON */
00038 /* */
00039 #define cTS_GETY    (cTS_STARTBIT|cTS_MODE|cTS_SERDFR|cTS_PWRUP|0x10)
00040 #define cTS_GETX    (cTS_STARTBIT|cTS_MODE|cTS_SERDFR|cTS_PWRUP|0x50)
00041 #define cTS_GETZ1    (cTS_STARTBIT|cTS_MODE|cTS_SERDFR|cTS_PWRUP|0x30)
00042 #define cTS_GETZ2    (cTS_STARTBIT|cTS_MODE|cTS_SERDFR|cTS_PWRUP|0x40)
00043 #define cTS_VBAT    (cTS_STARTBIT|cTS_MODE|cTS_SERDFR|cTS_PWRUP|0x20)
00044 #define cTS_END        (cTS_STARTBIT|cTS_MODE|cTS_SERDFR|cTS_PWRDWN|0x50)
00045 /* */
00046 #define cTS_CMDSIZE    17
00047 #define cTS_CROCINO    16
00048 /* */
00049 #define cTS_DEBOUNCE    2        /* 3ms di debounce x la pressione del touch */
00050 /* FSM per la lettura del touch */
00051 #define cTS_INIT        6
00052 #define cTS_START       1
00053 #define cTS_READ        2
00054 #define cTS_RELEASING   3
00055 #define cTS_RELEASED    4
00056 #define cTS_STOP        5
00057 
00058 #define TS_SPEED            1000000        /* 1Mbit */
00059 #define BUS_MODE            3
00060 
00061 /* We read the sample MAX_SAMPLES times*/
00062 #define    MAX_SAMPLES        8
00063 
00064 
00065 /* Data structure: x, y and pressure */
00066 struct _TS_COORD {
00067     unsigned int        x;
00068     unsigned int        y;
00069     int                 z;
00070 };
00071 
00072 /* Collection of data about the touch... */
00073 struct _TS_VALUE {
00074     _TS_COORD                   coord;              /* tap's coord. */
00075     volatile unsigned char      touched;            /* == 1 pen down. */
00076     unsigned char               calibration_done;   /* calibration done. */
00077 };
00078 
00079 /** TouchScreen ADS7846 Library
00080  *  From the DS:
00081  * The ADS7846 is a classic successive approximation register
00082  * (SAR) analog-to-digital converter (ADC). The architecture is
00083  * based on capacitive redistribution which inherently includes
00084  * a sample-and-hold function. The converter is fabricated on a
00085  * 0.6μm CMOS process.
00086  * 
00087  * The device features an internal 2.5V reference and an
00088  * external clock. Operation is maintained from a single supply
00089  * of 2.7V to 5.25V. The internal reference can be overdriven
00090  * with an external, low impedance source between 1V and
00091  * +VCC. The value of the reference voltage directly sets the
00092  * input range of the converter.
00093  * The analog input (X-, Y-, and Z-position coordinates, auxiliary
00094  * input, battery voltage, and chip temperature) to the
00095  * converter is provided via a multiplexer. A unique configuration
00096  * of low on-resistance touch panel driver switches allows
00097  * an unselected ADC input channel to provide power and its
00098  * accompanying pin to provide ground for an external device,
00099  * such as a touch screen
00100  * 
00101  * Example:
00102  * @code
00103  * // Please the main.c code as an elabora example.
00104  *
00105  * @endcode
00106  */
00107 
00108 //
00109 class TOUCHS {
00110 
00111 public:
00112 
00113     /** Create the touch object
00114      *
00115      * @param pin mosi, pin miso, pin sclk, pin chip select and pin penirq
00116      */
00117     TOUCHS( PinName mosi, PinName miso, PinName sclk, PinName cs, PinName penirq);
00118     
00119     /** Initalize the touchscreen chip.
00120      *
00121      * @param none
00122      */
00123     void init( void);
00124 
00125     /** This function computes a matrix of data to be used for the conversion from touch to screen coord.
00126      * 
00127      * @param the coord of each crocino tapped by the user.
00128      */
00129     unsigned int setcalibration( _TS_COORD *ts);    
00130     
00131     /** I use a pool metod to read the touch. Each time I need to read the touch I loop until this function
00132      *  set a flag. It's also possible to configure this fuction as an handle of a Ticker class, checkin for 
00133      *  the flag inside the main loop.
00134      */
00135     void do_tap( void);
00136     
00137     /** Get the x coord of the crocino speicifyed by idx. There are three crocino defined inside the crocino.h header file
00138      *
00139      * @param idx One of the three crocino.
00140      * @return the x coord.
00141      */
00142     unsigned int getcrocino_x( unsigned char idx);
00143     
00144     /** Get the y coord of the crocino speicifyed by idx. There are three crocino defined inside the crocino.h header file
00145      *
00146      * @param idx One of the three crocino.
00147      * @return the x coord.
00148      */    
00149     unsigned int getcrocino_y( unsigned char idx);
00150     
00151     /** Get the pixel size of the crocino.
00152      *
00153      * @return the pixel size of the crocino.
00154      */    
00155     unsigned int crocino_size( void);
00156     
00157     /** Return the size of the TS_Matrix size.
00158      *
00159      * @return the size of the TS_Matrix
00160      */
00161     unsigned int gettsmatrixsize( void);
00162     
00163     /** Get the TS_Matrix 
00164      *
00165      * @param pmatrix Pointer to an area of RAM where the function store the content of the TS_Matrix
00166      */
00167     void gettsmatrix( unsigned char *pmatrix);
00168     
00169     /** Set the TS_Matrix with the content of the buffer.
00170      *
00171      * @param pmatrix Pointer to a buffer 
00172      */
00173     void settsmatrix( unsigned char *pmatrix);
00174     
00175     //
00176     _TS_VALUE       ts_val;
00177     
00178 protected:
00179     /**
00180      */
00181     unsigned int pressure( void);
00182         
00183     /** This function convert from touch to screen coord.
00184      *  The value are stored inside the struct ts_val
00185      */
00186     unsigned int calibrate( void);
00187 
00188     /** Read the raw coordinate from the touchscreen 
00189      *
00190      * @param struct ts that will old the data.
00191      */
00192     void read( _TS_COORD *ts);
00193     
00194     _TS_VALUE       TS_value;
00195     _TS_COORD       TS_coord;
00196     SPI             _spi;
00197     DigitalOut      _cs;
00198     InterruptIn     _penirq;
00199 };
00200 
00201 #endif