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 dcTft, PinName blTft,
00022                                    PinName csSd):
00023 #ifdef USE_SDCARD
00024     SDFileSystem(mosi,miso,sclk,csSd, "sdc"),
00025 #endif
00026     SPI_TFT_ILI9341(mosi,miso,sclk,csTft,NC,dcTft, "tft"),
00027     bl(blTft)
00028 {
00029 #ifndef USE_SDCARD
00030     // sd card
00031     DigitalOut cs(csSd);
00032     cs = 1;
00033 #endif
00034     // backlight
00035     bl = 1;
00036     font = NULL;
00037     // touch screen pins
00038     _xp = xp;
00039     _yp = yp;
00040     _xm = xm;
00041     _ym = ym;
00042     // default touch calibration
00043     // orientation     //      0      1      2      3
00044     x_off = 108000;  //  17252  16605 108755 108000
00045     y_off =  22000;  //  22330 105819  97167  22000
00046     pp_tx =   -291;  //    378    289   -390   -291
00047     pp_ty =    356;  //    261   -355   -239    356
00048 }
00049 
00050 void SeeedStudioTFTv2::setBacklight(bool enabled)
00051 {
00052     bl = enabled;
00053 }
00054 
00055 int SeeedStudioTFTv2::readTouch(PinName p, PinName m, PinName a, PinName i)
00056 {
00057     DigitalOut _p(p);
00058     _p = 1;
00059     DigitalOut _m(m);
00060     _m = 0;
00061     AnalogIn   _a(a);
00062     AnalogIn   _i(i); // this pin has to be high Z (DigitalIn may also work)
00063     wait_us(10);
00064     return _a.read_u16();
00065 }
00066 
00067 SeeedStudioTFTv2::TOUCH SeeedStudioTFTv2::getTouch(point& p)
00068 {
00069     int y2 = readTouch(_xp,_xm,_yp,_ym);
00070     int x2 = readTouch(_yp,_ym,_xp,_xm);
00071     int y1 = readTouch(_xp,_xm,_yp,_ym);
00072     int x1 = readTouch(_yp,_ym,_xp,_xm);
00073     int xd = x1 - x2;
00074     int yd = y1 - y2;
00075     xd = (xd > 0) ? xd : -xd;
00076     yd = (yd > 0) ? xd : -xd;
00077     p.x = x1 + x2;
00078     p.y = y1 + y2;
00079 #if 0
00080     DigitalOut _p(_xp);
00081     _p = 1;
00082     DigitalOut _m(_ym);
00083     _m = 0;
00084     AnalogIn   _ax(_xm);
00085     AnalogIn   _ay(_yp);
00086     wait_us(20);
00087     int ax = _ax.read_u16();
00088     int ay = _ay.read_u16();
00089     float z = 0;
00090     z  = (float)ay / ax / x / 2 * 0x10000;
00091 #endif
00092     const int th = 2000;
00093     const int df =  100;
00094     TOUCH touch;
00095     if (x1 < th || x2 < th ||
00096             y1 < th || y2 < th) {
00097         p.x = 0;
00098         p.y = 0;
00099         touch = NO;
00100     } else if (xd > df || yd > df) {
00101         touch = MAYBE;
00102     } else {
00103         touch = YES;
00104     }
00105     //int temp = p.x;
00106     //p.x = p.y;
00107     //p.y = temp;
00108     //locate(0,50);
00109     //printf("x: %6i y: %6i",p.x,p.y);
00110     return touch;
00111 }
00112 
00113 void SeeedStudioTFTv2::calibrate(void)
00114 {
00115     int i;
00116     int a = 0,b = 0,c = 0, d = 0;
00117     int pos_x = 0, pos_y = 0;
00118     point p;
00119 
00120     cls();
00121     foreground(White);    // set chars to white
00122     line(0,3,6,3,White);
00123     line(3,0,3,6,White);
00124     if (font)
00125     {
00126         // get the center of the screen
00127         pos_x = columns() / 2 - 3;
00128         pos_x = pos_x * font[1];
00129         pos_y = (rows() / 2) - 1;
00130         pos_y = pos_y * font[2];
00131         locate(pos_x,pos_y);
00132         printf("press cross    ");
00133         locate(pos_x,pos_y + font[2]);
00134         printf("to calibrate   ");
00135     }
00136     for (i=0; i<5; i++) {
00137         while (getTouch(p) != YES)
00138             /*nothing*/;
00139         a += p.x;
00140         b += p.y;
00141     }
00142     a = a / 5;
00143     b = b / 5;
00144     if (font)
00145     {
00146         locate(pos_x,pos_y);
00147         printf("ok             ");
00148         locate(pos_x,pos_y + font[2]);
00149         printf("release touch  ");
00150     }
00151     while (getTouch(p) != NO)
00152         /*nothing*/;
00153     cls();
00154     line(width() -5, height() - 8,width() - 5,height() -1,White);   // paint cross
00155     line(width() - 8,height() - 5,width() - 1,height() - 5,White);
00156     if (font)
00157     {
00158         locate(pos_x,pos_y);
00159         printf("press cross    ");
00160         locate(pos_x,pos_y + font[2]);
00161         printf("to calibrate   ");
00162     }
00163     for (i=0; i<5; i++) {
00164         while (getTouch(p) != YES)
00165             /*nothing*/;
00166         c+= p.x;
00167         d+= p.y;
00168     }
00169     c = c / 5;
00170     d = d / 5;
00171     x_off = a;
00172     y_off = b;
00173     i = c-a;  // delta x
00174     pp_tx = i / (width() - 6);
00175     i = d-b;  // delta y
00176     pp_ty = i / (height() - 6);
00177     if (font)
00178     {
00179         locate(pos_x,pos_y);
00180         printf("Calibrated     ");
00181         locate(pos_x,pos_y + font[2]);
00182         printf("x %6i %4i", x_off, pp_tx);
00183         locate(pos_x,pos_y + 2*font[2]);
00184         printf("y %6i %4i", y_off, pp_ty);
00185     }
00186     while (getTouch(p) != NO)
00187         /*nothing*/;
00188     cls();
00189 }
00190 
00191 point SeeedStudioTFTv2::toPixel(point p)
00192 {
00193     p.x -= x_off;
00194     p.x /= pp_tx;
00195     int w = width();
00196     if (p.x > w) p.x = w;
00197     if (p.x < 0) p.x = 0;
00198     p.y -= y_off;
00199     p.y /= pp_ty;
00200     int h = height();
00201     if (p.y > h) p.y = h;
00202     if (p.y < 0) p.y = 0;
00203     return (p);
00204 }
00205 
00206 bool SeeedStudioTFTv2::getPixel(point& p)
00207 {
00208     TOUCH touch = getTouch(p);
00209     p = toPixel(p);
00210     return touch == YES;
00211 }