touch_tft.h

00001 /* mbed library for touchscreen connected to 4 mbed pins
00002  * derive from SPI_TFT lib 
00003  * Copyright (c) 2011 Peter Drescher - DC2PD
00004  *
00005  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00006  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00007  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00008  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00009  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00010  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00011  * THE SOFTWARE.
00012  */
00013 
00014 #ifndef MBED_TOUCH_H
00015 #define MBED_TOUCH_H
00016 
00017 #include "mbed.h"
00018 #include "SPI_TFT.h"
00019 
00020 struct point{
00021        unsigned short x;
00022        unsigned short y;
00023        };
00024 
00025 
00026 /** touchscreen control class, based on SPI_TFT
00027  *
00028  * Example:
00029  * @code
00030  * 
00031  * #include "mbed.h"
00032  * #include "SPI_TFT.h"
00033  * #include "Arial12x12.h"
00034  * #include "Arial28x28.h"
00035  * #include "touch_tft.h"
00036  * // the TFT is connected to SPI pin 5-7
00037  * // the touch is connected to 19,20,16,17
00038  *
00039  * touch_tft tt(p19,p20,p16,p17,p5, p6, p7, p8, p15,"TFT"); // x+,x-,y+,y-,mosi, miso, sclk, cs, reset
00040  *
00041  * int main() {
00042  * point p;
00043  *
00044  *  tt.claim(stdout);        // send stdout to the TFT display
00045  *  tt.background(Black);    // set background to black
00046  *  tt.foreground(White);    // set chars to white
00047  *  tt.cls();                // clear the screen
00048  *  tt.set_font((unsigned char*) Arial12x12);  // select the font
00049  *  tt.set_orientation(1);
00050  *
00051  *  tt.calibrate();          // calibrate the touch
00052  * while (1) {
00053  *       p = tt.get_touch();   // read analog pos.
00054  *       if (tt.is_touched(p)) {  // test if touched
00055  *           p = tt.to_pixel(p);             // convert to pixel pos
00056  *           tt.fillcircle(p.x,p.y,3,Blue);  // print a blue dot on the screen
00057  *     }
00058  * }
00059  * @endcode
00060  */
00061 class touch_tft : public  SPI_TFT{
00062 public:
00063     /** create a TFT with touch object connected to the pins:
00064      *
00065      * @param pin xp resistiv touch x+
00066      * @param pin xm resistiv touch x-
00067      * @param pin yp resistiv touch y+
00068      * @param pin ym resistiv touch y-
00069      * @param mosi,miso,sclk SPI connection to TFT
00070      * @param cs pin connected to CS of display
00071      * @param reset pin connected to RESET of display 
00072      * based on my SPI_TFT lib
00073      */
00074     touch_tft(PinName xp, PinName xm, PinName yp, PinName ym,PinName mosi, PinName miso, PinName sclk, PinName cs, PinName reset,const char* name ="TFT");
00075     
00076     /** calibrate the touch display
00077      *
00078      * User is asked to touch on two points on the screen
00079      */   
00080     void calibrate(void);
00081     
00082     /** read x and y analog samples
00083      *
00084      * @returns point(x,y)
00085      */
00086     point get_touch(void);
00087     
00088     /** calculate coord on screen
00089      *
00090      * @param a_point point(analog x, analog y)
00091      * @returns point(pixel x, pixel y)
00092      *
00093      */
00094     point to_pixel(point a_point);
00095     
00096     /** test if screen is touched
00097      * 
00098      * @param point analog x,y
00099      * @returns true is touched
00100      *
00101      */   
00102     bool is_touched(point a);    
00103     
00104 protected:
00105     DigitalInOut _xp;
00106     DigitalInOut _xm;
00107     DigitalInOut _yp;
00108     DigitalInOut _ym;
00109     AnalogIn     _ax;
00110     AnalogIn     _ay;
00111     PinName xa;
00112     PinName ya;
00113     
00114     
00115     unsigned short x_a,y_a;
00116     unsigned short x_off,y_off;
00117     unsigned short pp_tx,pp_ty;
00118     
00119     
00120            
00121     };
00122 
00123 #endif