Erik -
Simple clock program for LPC1768 Mini-DK
Diff: Mini_DK/TouchADS7843/Touch.cpp
- Revision:
- 0:ab0aec01b38e
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Mini_DK/TouchADS7843/Touch.cpp Sun Dec 30 21:31:56 2012 +0000
@@ -0,0 +1,259 @@
+// Code based on Carlos E. Vidales tutorial : How To Calibrate Touch Screens
+// http://www.embedded.com/design/configurable-systems/4023968/How-To-Calibrate-Touch-Screens
+
+#include "Touch.h"
+#include "mbed.h"
+#include "Arial12x12.h"
+
+// (To be modified) C code below works on KEIL compiler but NOT on LPCXpresso/mbed
+//Matrix matrix ;
+//Coordinate display ;
+
+Coordinate ScreenSample[3] = {
+ { 45, 45 },
+ { 45, 270},
+ { 190,190}
+} ;
+Coordinate DisplaySample[3] = {
+ { 45, 45 },
+ { 45, 270},
+ { 190,190}
+} ;
+
+#define THRESHOLD 2
+// **********************************************************************
+
+TouchScreenADS7843::TouchScreenADS7843(PinName tp_mosi,PinName tp_miso,PinName tp_sclk,PinName tp_cs,PinName tp_irq,PinName mosi, PinName miso, PinName sclk, PinName cs, PinName reset,const char* name)
+ : SPI_TFT(mosi,miso,sclk,cs,reset,name), _tp_spi(tp_mosi, tp_miso, tp_sclk), _tp_cs(tp_cs), _tp_irq(tp_irq){}
+// **********************************************************************
+void TouchScreenADS7843::TP_Init(void)
+{
+ _tp_cs=1;
+ _tp_spi.frequency(500000);
+ _tp_spi.format(8,0); // 8 bit spi mode 3
+}
+
+int TouchScreenADS7843::Read_XY(unsigned char XY)
+{
+ unsigned char msb, lsb;
+ unsigned int Temp;
+
+ Temp=0;
+ _tp_cs=0;
+ wait_us(SPI_RD_DELAY);
+ _tp_spi.write(XY);
+ wait_us(SPI_RD_DELAY);
+ msb = _tp_spi.write(0x00); // msb
+ wait_us(SPI_RD_DELAY);
+ lsb = _tp_spi.write(0x00); // lsb
+ _tp_cs=1;
+ Temp = ((msb <<8 ) | lsb);
+ Temp >>= 3;
+ Temp &= 0xfff;
+ Temp /= 4; // Scaling : return value range must be between 0 and 1024
+// Temp = (((msb & 0x7f) <<8) | lsb) >> 3; // 12 bit
+ return(Temp);
+}
+
+
+void TouchScreenADS7843::TP_GetAdXY(int *x,int *y)
+{
+ int adx,ady;
+ adx = Read_XY(CHX);
+ wait_us(1);
+ ady = Read_XY(CHY);
+ *x = adx;
+ *y = ady;
+}
+
+void TouchScreenADS7843::TP_DrawPoint(unsigned int Xpos,unsigned int Ypos, unsigned int color)
+{
+ wr_reg(0x03, 0x1030);
+ WindowMax();
+ pixel(Xpos,Ypos,color);
+ pixel(Xpos+1,Ypos,color);
+ pixel(Xpos,Ypos+1,color);
+ pixel(Xpos+1,Ypos+1,color);
+}
+
+void TouchScreenADS7843::DrawCross(unsigned int Xpos,unsigned int Ypos)
+{
+ line(Xpos-15,Ypos,Xpos-2,Ypos,White);
+ line(Xpos+2,Ypos,Xpos+15,Ypos,White);
+ line(Xpos,Ypos-15,Xpos,Ypos-2,White);
+ line(Xpos,Ypos+2,Xpos,Ypos+15,White);
+
+ line(Xpos-15,Ypos+15,Xpos-7,Ypos+15,DarkGrey);
+ line(Xpos-15,Ypos+7,Xpos-15,Ypos+15,DarkGrey);
+
+ line(Xpos-15,Ypos-15,Xpos-7,Ypos-15,DarkGrey);
+ line(Xpos-15,Ypos-7,Xpos-15,Ypos-15,DarkGrey);
+
+ line(Xpos+7,Ypos+15,Xpos+15,Ypos+15,DarkGrey);
+ line(Xpos+15,Ypos+7,Xpos+15,Ypos+15,DarkGrey);
+
+ line(Xpos+7,Ypos-15,Xpos+15,Ypos-15,DarkGrey);
+ line(Xpos+15,Ypos-15,Xpos+15,Ypos-7,DarkGrey);
+}
+
+unsigned char TouchScreenADS7843::Read_Ads7846(Coordinate * screenPtr)
+{
+// static Coordinate screen;
+ int m0,m1,m2,TP_X[1],TP_Y[1],temp[3];
+ uint8_t count=0;
+ int buffer[2][9]={{0},{0}};
+ do
+ {
+ TP_GetAdXY(TP_X,TP_Y);
+ buffer[0][count]=TP_X[0];
+ buffer[1][count]=TP_Y[0];
+ count++;
+ }
+ while(!_tp_irq && (count < 9));
+ if(count==9)
+ {
+ temp[0]=(buffer[0][0]+buffer[0][1]+buffer[0][2])/3;
+ temp[1]=(buffer[0][3]+buffer[0][4]+buffer[0][5])/3;
+ temp[2]=(buffer[0][6]+buffer[0][7]+buffer[0][8])/3;
+ m0=temp[0]-temp[1];
+ m1=temp[1]-temp[2];
+ m2=temp[2]-temp[0];
+ m0=m0>0?m0:(-m0);
+ m1=m1>0?m1:(-m1);
+ m2=m2>0?m2:(-m2);
+ if( (m0>THRESHOLD) && (m1>THRESHOLD) && (m2>THRESHOLD) ) return 0;
+ if(m0<m1)
+ {
+ if(m2<m0)
+ screenPtr->x=(temp[0]+temp[2])/2;
+ else
+ screenPtr->x=(temp[0]+temp[1])/2;
+ }
+ else if(m2<m1)
+ screenPtr->x=(temp[0]+temp[2])/2;
+ else
+ screenPtr->x=(temp[1]+temp[2])/2;
+
+ temp[0]=(buffer[1][0]+buffer[1][1]+buffer[1][2])/3;
+ temp[1]=(buffer[1][3]+buffer[1][4]+buffer[1][5])/3;
+ temp[2]=(buffer[1][6]+buffer[1][7]+buffer[1][8])/3;
+ m0=temp[0]-temp[1];
+ m1=temp[1]-temp[2];
+ m2=temp[2]-temp[0];
+ m0=m0>0?m0:(-m0);
+ m1=m1>0?m1:(-m1);
+ m2=m2>0?m2:(-m2);
+ if( (m0>THRESHOLD) && (m1>THRESHOLD) && (m2>THRESHOLD) ) return 0;
+
+ if(m0<m1)
+ {
+ if(m2<m0)
+ screenPtr->y=(temp[0]+temp[2])/2;
+ else
+ screenPtr->y=(temp[0]+temp[1])/2;
+ }
+ else if(m2<m1)
+ screenPtr->y=(temp[0]+temp[2])/2;
+ else
+ screenPtr->y=(temp[1]+temp[2])/2;
+ return 1;
+ }
+ return 0;
+}
+
+uint8_t TouchScreenADS7843::setCalibrationMatrix( Coordinate * displayPtr,
+ Coordinate * screenPtr,
+ Matrix * matrixPtr)
+{
+ uint8_t retTHRESHOLD = 0 ;
+ // K = (Xs0 - Xs2)*(Ys1 - Ys2) - (Xs1 - Xs2)*(Ys0 - Ys2)
+ matrixPtr->Divider = ((screenPtr[0].x - screenPtr[2].x) * (screenPtr[1].y - screenPtr[2].y)) -
+ ((screenPtr[1].x - screenPtr[2].x) * (screenPtr[0].y - screenPtr[2].y)) ;
+ if( matrixPtr->Divider == 0 )
+ {
+ retTHRESHOLD = 1;
+ }
+ else
+ {
+ // (Xd0 - Xd2)*(Ys1 - Ys2) - (Xd1 - Xd2)*(Ys0 - Ys2)
+ // A = ---------------------------------------------------
+ // K
+ matrixPtr->An = ((displayPtr[0].x - displayPtr[2].x) * (screenPtr[1].y - screenPtr[2].y)) -
+ ((displayPtr[1].x - displayPtr[2].x) * (screenPtr[0].y - screenPtr[2].y)) ;
+ // (Xs0 - Xs2)*(Xd1 - Xd2) - (Xd0 - Xd2)*(Xs1 - Xs2)
+ // B = ---------------------------------------------------
+ // K
+ matrixPtr->Bn = ((screenPtr[0].x - screenPtr[2].x) * (displayPtr[1].x - displayPtr[2].x)) -
+ ((displayPtr[0].x - displayPtr[2].x) * (screenPtr[1].x - screenPtr[2].x)) ;
+ // Ys0*(Xs2*Xd1 - Xs1*Xd2) + Ys1*(Xs0*Xd2 - Xs2*Xd0) + Ys2*(Xs1*Xd0 - Xs0*Xd1)
+ // C = ----------------------------------------------------------------------------
+ // K
+ matrixPtr->Cn = (screenPtr[2].x * displayPtr[1].x - screenPtr[1].x * displayPtr[2].x) * screenPtr[0].y +
+ (screenPtr[0].x * displayPtr[2].x - screenPtr[2].x * displayPtr[0].x) * screenPtr[1].y +
+ (screenPtr[1].x * displayPtr[0].x - screenPtr[0].x * displayPtr[1].x) * screenPtr[2].y ;
+ // (Yd0 - Yd2)*(Ys1 - Ys2) - (Yd1 - Yd2)*(Ys0 - Ys2)
+ // D = ---------------------------------------------------
+ // K
+ matrixPtr->Dn = ((displayPtr[0].y - displayPtr[2].y) * (screenPtr[1].y - screenPtr[2].y)) -
+ ((displayPtr[1].y - displayPtr[2].y) * (screenPtr[0].y - screenPtr[2].y)) ;
+ // (Xs0 - Xs2)*(Yd1 - Yd2) - (Yd0 - Yd2)*(Xs1 - Xs2)
+ // E = ---------------------------------------------------
+ // K
+ matrixPtr->En = ((screenPtr[0].x - screenPtr[2].x) * (displayPtr[1].y - displayPtr[2].y)) -
+ ((displayPtr[0].y - displayPtr[2].y) * (screenPtr[1].x - screenPtr[2].x)) ;
+ // Ys0*(Xs2*Yd1 - Xs1*Yd2) + Ys1*(Xs0*Yd2 - Xs2*Yd0) + Ys2*(Xs1*Yd0 - Xs0*Yd1)
+ // F = ----------------------------------------------------------------------------
+ // K
+ matrixPtr->Fn = (screenPtr[2].x * displayPtr[1].y - screenPtr[1].x * displayPtr[2].y) * screenPtr[0].y +
+ (screenPtr[0].x * displayPtr[2].y - screenPtr[2].x * displayPtr[0].y) * screenPtr[1].y +
+ (screenPtr[1].x * displayPtr[0].y - screenPtr[0].x * displayPtr[1].y) * screenPtr[2].y ;
+ }
+ return( retTHRESHOLD ) ;
+}
+
+uint8_t TouchScreenADS7843::getDisplayPoint(Coordinate *displayPtr,
+ Coordinate *screenPtr,
+ Matrix *matrixPtr )
+{
+ uint8_t retTHRESHOLD = 0 ;
+
+ if( matrixPtr->Divider != 0 )
+ {
+ // XD = AX+BY+C
+ displayPtr->x = ( (matrixPtr->An * screenPtr->x) +
+ (matrixPtr->Bn * screenPtr->y) +
+ matrixPtr->Cn
+ ) / matrixPtr->Divider ;
+ // YD = DX+EY+F
+ displayPtr->y = ( (matrixPtr->Dn * screenPtr->x) +
+ (matrixPtr->En * screenPtr->y) +
+ matrixPtr->Fn
+ ) / matrixPtr->Divider ;
+ }
+ else
+ {
+ retTHRESHOLD = 1;
+ }
+ return(retTHRESHOLD);
+}
+
+void TouchScreenADS7843::TouchPanel_Calibrate(Matrix *matrixPtr)
+{
+ uint8_t i;
+ Coordinate screen_cal;
+ setCalibrationMatrix( &DisplaySample[0],&ScreenSample[0],matrixPtr ) ;
+ set_font((unsigned char*) Arial12x12);
+ for(i=0;i<3;i++)
+ {
+ cls();
+ locate(10,10);
+ printf("Touch crosshair to calibrate");
+ wait_ms(500);
+ DrawCross(DisplaySample[i].x,DisplaySample[i].y);
+ do {} while (!Read_Ads7846(&screen_cal));
+ ScreenSample[i].x= screen_cal.x; ScreenSample[i].y= screen_cal.y;
+ }
+ setCalibrationMatrix( &DisplaySample[0],&ScreenSample[0],matrixPtr ) ;
+ cls();
+}
+