SeeedStudioTFTv2.cpp

00001 /* mbed library for resistive touch pads
00002  * uses 4 pins - 2 IO and 2 Analog
00003 
00004  * c 2011 Peter Drescher - DC2PD
00005  *
00006  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00007  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00008  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00009  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00010  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00011  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00012  * THE SOFTWARE.
00013  */
00014 
00015  
00016 #include "mbed.h"
00017 #include "SeeedStudioTFTv2.h"
00018 
00019 SeeedStudioTFTv2::SeeedStudioTFTv2(PinName xp, PinName xm, PinName yp, PinName ym,
00020                                    PinName mosi, PinName miso, PinName sclk,
00021                                    PinName csTft, PinName rstTft, PinName dcTft):
00022     SPI_TFT_ILI9341(mosi,miso,sclk,csTft,rstTft,dcTft, "tft")
00023 {
00024     // touch screen pins
00025     _xp = xp;
00026     _yp = yp;
00027     _xm = xm;
00028     _ym = ym;
00029     // default touch calibration
00030     // orientation  //      0      1      2      3
00031     x_off =  116670 ;  //  17252  16605 108755 108000
00032     y_off =  29042 ;  //  22330 105819  97167  22000
00033     pp_tx =   -291;  //    378    289   -390   -291
00034     pp_ty =    306;  //    261   -355   -239    356
00035 }
00036 
00037 int SeeedStudioTFTv2::readTouch(PinName p, PinName m, PinName a, PinName i)
00038 {
00039     DigitalOut _p(p);
00040     _p = 1;
00041     DigitalOut _m(m);
00042     _m = 0;
00043     AnalogIn   _a(a);
00044     AnalogIn   _i(i); // this pin has to be high Z (DigitalIn may also work)
00045     wait_us(10);
00046     return _a.read_u16();
00047 }
00048 
00049 SeeedStudioTFTv2::TOUCH SeeedStudioTFTv2::getTouch(point& p)
00050 {
00051     int y2 = readTouch(_xp,_xm,_yp,_ym);
00052     int x2 = readTouch(_yp,_ym,_xp,_xm);
00053     int y1 = readTouch(_xp,_xm,_yp,_ym);
00054     int x1 = readTouch(_yp,_ym,_xp,_xm);
00055     int xd = x1 - x2;
00056     int yd = y1 - y2;
00057     xd = (xd > 0) ? xd : -xd;
00058     yd = (yd > 0) ? xd : -xd;
00059     p.x = x1 + x2;
00060     p.y = y1 + y2;
00061 #if 0
00062     DigitalOut _p(_xp);
00063     _p = 1;
00064     DigitalOut _m(_ym);
00065     _m = 0;
00066     AnalogIn   _ax(_xm);
00067     AnalogIn   _ay(_yp);
00068     wait_us(20);
00069     int ax = _ax.read_u16();
00070     int ay = _ay.read_u16();
00071     float z = 0;
00072     z  = (float)ay / ax / x / 2 * 0x10000;
00073 #endif
00074     const int th = 8000;
00075     const int df =  100;
00076     TOUCH touch;
00077     if (x1 < th || x2 < th ||
00078             y1 < th || y2 < th) {
00079         p.x = 0;
00080         p.y = 0;
00081         touch = NO;
00082     } else if (xd > df || yd > df) {
00083         touch = MAYBE;
00084     } else {
00085         touch = YES;
00086     }
00087     //debug
00088     //locate(0,50);
00089     //printf("x: %6i y: %6i",p.x,p.y);
00090     return touch;
00091 }
00092 
00093 void SeeedStudioTFTv2::calibrate(void)
00094 {
00095     int i;
00096     int a = 0,b = 0,c = 0, d = 0;
00097     int pos_x = 0, pos_y = 0;
00098     point p;
00099 
00100     cls();
00101     foreground(White);    // set chars to white
00102     line(0,3,6,3,White);
00103     line(3,0,3,6,White);
00104     if (font)
00105     {
00106         // get the center of the screen
00107         pos_x = columns() / 2 - 3;
00108         pos_x = pos_x * font[1];
00109         pos_y = (rows() / 2) - 1;
00110         pos_y = pos_y * font[2];
00111         locate(pos_x,pos_y);
00112         printf("press cross    ");
00113         locate(pos_x,pos_y + font[2]);
00114         printf("to calibrate   ");
00115     }
00116     for (i=0; i<5; i++) {
00117         while (getTouch(p) != YES)
00118             /*nothing*/;
00119         a += p.x;
00120         b += p.y;
00121     }
00122     a = a / 5;
00123     b = b / 5;
00124     if (font)
00125     {
00126         locate(pos_x,pos_y);
00127         printf("ok             ");
00128         locate(pos_x,pos_y + font[2]);
00129         printf("release touch  ");
00130     }
00131     while (getTouch(p) != NO)
00132         /*nothing*/;
00133     cls();
00134     line(width() -5, height() - 8,width() - 5,height() -1,White);   // paint cross
00135     line(width() - 8,height() - 5,width() - 1,height() - 5,White);
00136     if (font)
00137     {
00138         locate(pos_x,pos_y);
00139         printf("press cross    ");
00140         locate(pos_x,pos_y + font[2]);
00141         printf("to calibrate   ");
00142     }
00143     for (i=0; i<5; i++) {
00144         while (getTouch(p) != YES)
00145             /*nothing*/;
00146         c+= p.x;
00147         d+= p.y;
00148     }
00149     c = c / 5;
00150     d = d / 5;
00151     x_off = a;
00152     y_off = b;
00153     i = c-a;  // delta x
00154     pp_tx = i / (width() - 6);
00155     i = d-b;  // delta y
00156     pp_ty = i / (height() - 6);
00157     if (font)
00158     {
00159         locate(pos_x,pos_y);
00160         printf("Calibrated     ");
00161         locate(pos_x,pos_y + font[2]);
00162         printf("x %6i %4i", x_off, pp_tx);
00163         locate(pos_x,pos_y + 2*font[2]);
00164         printf("y %6i %4i", y_off, pp_ty);
00165     }
00166     while (getTouch(p) != NO)
00167         /*nothing*/;
00168     cls();
00169     
00170    Ecrire_Calibration(x_off, y_off, pp_tx, pp_ty);
00171 }
00172 
00173 point SeeedStudioTFTv2::toPixel(point p)
00174 {
00175     p.x -= x_off;
00176     p.x /= pp_tx;
00177     int w = width();
00178     if (p.x > w) p.x = w;
00179     if (p.x < 0) p.x = 0;
00180     p.y -= y_off;
00181     p.y /= pp_ty;
00182     int h = height();
00183     if (p.y > h) p.y = h;
00184     if (p.y < 0) p.y = 0;
00185     return (p);
00186 }
00187 
00188 bool SeeedStudioTFTv2::getPixel(point& p)
00189 {
00190     TOUCH touch = getTouch(p);
00191     p = toPixel(p);
00192     return touch == YES;
00193 }
00194 
00195 void SeeedStudioTFTv2::Ecrire_Calibration(signed long x_off, signed long y_off, signed long pp_tx, signed long pp_ty)
00196 {
00197     FILE* fichier = fopen("/local/calib.txt", "w");
00198     
00199     fprintf(fichier,"%d %d %d %d", x_off, y_off, pp_tx, pp_ty);
00200     
00201     fclose(fichier);    
00202 }
00203 
00204 void SeeedStudioTFTv2::Lire_Calibration(void)
00205 {
00206    
00207     FILE* fichier = fopen("/local/calib.txt", "r");
00208     
00209     fscanf(fichier,"%d %d %d %d", &x_off, &y_off, &pp_tx, &pp_ty);
00210                 
00211     fclose(fichier);
00212      
00213 }
00214 void SeeedStudioTFTv2::CheckCalibTXT(void)
00215 {
00216     FILE* fpi = fopen("/local/calib.txt", "r");
00217 
00218     if (fpi == NULL) 
00219     {
00220         calibrate();          // calibrate the touch
00221     } 
00222     else
00223     {
00224         fclose(fpi);
00225         Lire_Calibration();
00226     }
00227 }