Marcel Visser
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RA8875_Touch.cpp
00001 /// This file contains the RA8875 Touch panel methods. 00002 /// 00003 00004 #include "RA8875.h" 00005 00006 // ### Touch Panel support code additions begin here 00007 00008 RetCode_t RA8875::TouchPanelInit(void) 00009 { 00010 //TPCR0: Set enable bit, default sample time, wakeup, and ADC clock 00011 WriteCommand(TPCR0, TP_ENABLE | TP_ADC_SAMPLE_DEFAULT_CLKS | TP_ADC_CLKDIV_DEFAULT); 00012 // TPCR1: Set auto/manual, Ref voltage, debounce, manual mode params 00013 WriteCommand(TPCR1, TP_MODE_DEFAULT | TP_DEBOUNCE_DEFAULT); 00014 WriteCommand(INTC1, ReadCommand(INTC1) | RA8875_INT_TP); // reg INTC1: Enable Touch Panel Interrupts (D2 = 1) 00015 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear any TP interrupt flag 00016 return noerror; 00017 } 00018 00019 RetCode_t RA8875::TouchPanelInit(uint8_t bTpEnable, uint8_t bTpAutoManual, uint8_t bTpDebounce, uint8_t bTpManualMode, uint8_t bTpAdcClkDiv, uint8_t bTpAdcSampleTime) 00020 { 00021 // Parameter bounds check 00022 if( \ 00023 !(bTpEnable == TP_ENABLE || bTpEnable == TP_ENABLE) || \ 00024 !(bTpAutoManual == TP_MODE_AUTO || bTpAutoManual == TP_MODE_MANUAL) || \ 00025 !(bTpDebounce == TP_DEBOUNCE_OFF || bTpDebounce == TP_DEBOUNCE_ON) || \ 00026 !(bTpManualMode <= TP_MANUAL_LATCH_Y) || \ 00027 !(bTpAdcClkDiv <= TP_ADC_CLKDIV_128) || \ 00028 !(bTpAdcSampleTime <= TP_ADC_SAMPLE_65536_CLKS) \ 00029 ) return bad_parameter; 00030 // Construct the config byte for TPCR0 and write them 00031 WriteCommand(TPCR0, bTpEnable | bTpAdcClkDiv | bTpAdcSampleTime); // Note: Wakeup is never enabled 00032 // Construct the config byte for TPCR1 and write them 00033 WriteCommand(TPCR1, bTpManualMode | bTpDebounce | bTpManualMode); // Note: Always uses internal Vref. 00034 // Set up the interrupt flag and enable bits 00035 WriteCommand(INTC1, ReadCommand(INTC1) | RA8875_INT_TP); // reg INTC1: Enable Touch Panel Interrupts (D2 = 1) 00036 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear any TP interrupt flag 00037 return noerror; 00038 } 00039 00040 // +----------------------------------------------------+ 00041 // | | 00042 // | 1 | 00043 // | | 00044 // | | 00045 // | 2 | 00046 // | | 00047 // | | 00048 // | 3 | 00049 // | | 00050 // +----------------------------------------------------+ 00051 00052 00053 RetCode_t RA8875::TouchPanelCalibrate(tpMatrix_t * matrix) 00054 { 00055 return TouchPanelCalibrate(NULL, matrix); 00056 } 00057 00058 00059 RetCode_t RA8875::TouchPanelCalibrate(const char * msg, tpMatrix_t * matrix) 00060 { 00061 point_t pTest[3]; 00062 point_t pSample[3]; 00063 loc_t x,y; 00064 00065 cls(); 00066 if (msg) 00067 puts(msg); 00068 SetTextCursor(0,height()/2); 00069 pTest[0].x = 50; pTest[0].y = 50; 00070 pTest[1].x = width() - 50; pTest[1].y = height()/2; 00071 pTest[2].x = width()/2; pTest[2].y = height() - 50; 00072 for (int i=0; i<3; i++) { 00073 foreground(Blue); 00074 printf(" (%3d,%3d) => ", pTest[i].x, pTest[i].y); 00075 line(pTest[i].x-10, pTest[i].y, pTest[i].x+10, pTest[i].y, White); 00076 line(pTest[i].x, pTest[i].y-10, pTest[i].x, pTest[i].y+10, White); 00077 while (!TouchPanelA2DFiltered(&x, &y)) 00078 wait_ms(20); 00079 pSample[i].x = x; 00080 pSample[i].y = y; 00081 line(pTest[i].x-10, pTest[i].y, pTest[i].x+10, pTest[i].y, Black); 00082 line(pTest[i].x, pTest[i].y-10, pTest[i].x, pTest[i].y+10, Black); 00083 foreground(Blue); 00084 printf(" (%4d,%4d)\r\n", x,y); 00085 while (TouchPanelA2DFiltered(&x, &y)) 00086 wait_ms(20); 00087 wait(2); 00088 } 00089 return TouchPanelComputeCalibration(pTest, pSample, matrix); 00090 } 00091 00092 00093 /********************************************************************** 00094 * 00095 * Function: getDisplayPoint() 00096 * 00097 * Description: Given a valid set of calibration factors and a point 00098 * value reported by the touch screen, this function 00099 * calculates and returns the true (or closest to true) 00100 * display point below the spot where the touch screen 00101 * was touched. 00102 * 00103 * 00104 * 00105 * Argument(s): displayPtr (output) - Pointer to the calculated 00106 * (true) display point. 00107 * screenPtr (input) - Pointer to the reported touch 00108 * screen point. 00109 * matrixPtr (input) - Pointer to calibration factors 00110 * matrix previously calculated 00111 * from a call to 00112 * setCalibrationMatrix() 00113 * 00114 * 00115 * The function simply solves for Xd and Yd by implementing the 00116 * computations required by the translation matrix. 00117 * 00118 * /- -\ 00119 * /- -\ /- -\ | | 00120 * | | | | | Xs | 00121 * | Xd | | A B C | | | 00122 * | | = | | * | Ys | 00123 * | Yd | | D E F | | | 00124 * | | | | | 1 | 00125 * \- -/ \- -/ | | 00126 * \- -/ 00127 * 00128 * It must be kept brief to avoid consuming CPU cycles. 00129 * 00130 * Return: OK - the display point was correctly calculated 00131 * and its value is in the output argument. 00132 * NOT_OK - an error was detected and the function 00133 * failed to return a valid point. 00134 * 00135 * NOTE! NOTE! NOTE! 00136 * 00137 * setCalibrationMatrix() and getDisplayPoint() will do fine 00138 * for you as they are, provided that your digitizer 00139 * resolution does not exceed 10 bits (1024 values). Higher 00140 * resolutions may cause the integer operations to overflow 00141 * and return incorrect values. If you wish to use these 00142 * functions with digitizer resolutions of 12 bits (4096 00143 * values) you will either have to a) use 64-bit signed 00144 * integer variables and math, or b) judiciously modify the 00145 * operations to scale results by a factor of 2 or even 4. 00146 * 00147 */ 00148 bool RA8875::TouchPanelReadable(point_t * TouchPoint) 00149 { 00150 bool touched = false; 00151 point_t screenpoint = {0, 0}; 00152 00153 if (TouchPanelA2DFiltered(&screenpoint.x, &screenpoint.y)) { 00154 touched = true; 00155 if (tpMatrix.Divider != 0 && TouchPoint) { 00156 /* Operation order is important since we are doing integer */ 00157 /* math. Make sure you add all terms together before */ 00158 /* dividing, so that the remainder is not rounded off */ 00159 /* prematurely. */ 00160 TouchPoint->x = ( (tpMatrix.An * screenpoint.x) + 00161 (tpMatrix.Bn * screenpoint.y) + 00162 tpMatrix.Cn 00163 ) / tpMatrix.Divider ; 00164 00165 TouchPoint->y = ( (tpMatrix.Dn * screenpoint.x) + 00166 (tpMatrix.En * screenpoint.y) + 00167 tpMatrix.Fn 00168 ) / tpMatrix.Divider ; 00169 } else { 00170 touched = false; 00171 } 00172 } 00173 return touched; 00174 } 00175 00176 00177 RetCode_t RA8875::TouchPanelSetMatrix(tpMatrix_t * matrixPtr) 00178 { 00179 if (matrixPtr == NULL || matrixPtr->Divider == 0) 00180 return bad_parameter; 00181 memcpy(&tpMatrix, matrixPtr, sizeof(tpMatrix_t)); 00182 return noerror; 00183 } 00184 00185 00186 bool RA8875::TouchPanelA2DFiltered(loc_t *x, loc_t *y) 00187 { 00188 unsigned char touchready; 00189 static int xbuf[TPBUFSIZE], ybuf[TPBUFSIZE], sample = 0; 00190 int i, j, temp; 00191 00192 if( (ReadCommand(INTC2) & RA8875_INT_TP) ) { // Test for TP Interrupt pending in register INTC2 00193 // Get the next data samples 00194 ybuf[sample] = ReadCommand(TPYH) << 2 | ( (ReadCommand(TPXYL) & 0xC) >> 2 ); // D[9:2] from reg TPYH, D[1:0] from reg TPXYL[3:2] 00195 xbuf[sample] = ReadCommand(TPXH) << 2 | ( (ReadCommand(TPXYL) & 0x3) ); // D[9:2] from reg TPXH, D[1:0] from reg TPXYL[1:0] 00196 // Check for a complete set 00197 if(++sample == TPBUFSIZE) { 00198 // Buffers are full, so process them using Finn's method described in Analog Dialogue No. 44, Feb 2010 00199 // This requires sorting the samples in order of size, then discarding the top 25% and 00200 // bottom 25% as noise spikes. Finally, the middle 50% of the values are averaged to 00201 // reduce Gaussian noise. 00202 00203 // Sort the Y buffer using an Insertion Sort 00204 for(i = 1; i <= TPBUFSIZE; i++) { 00205 temp = ybuf[i]; 00206 j = i; 00207 while( j && (ybuf[j-1] > temp) ) { 00208 ybuf[j] = ybuf[j-1]; 00209 j = j-1; 00210 } 00211 ybuf[j] = temp; 00212 } // End of Y sort 00213 // Sort the X buffer the same way 00214 for(i = 1; i <= TPBUFSIZE; i++) { 00215 temp = xbuf[i]; 00216 j = i; 00217 while( j && (xbuf[j-1] > temp) ) { 00218 xbuf[j] = xbuf[j-1]; 00219 j = j-1; 00220 } 00221 xbuf[j] = temp; 00222 } // End of X sort 00223 // Average the middle half of the Y values and report them 00224 j = 0; 00225 for(i = (TPBUFSIZE/4) - 1; i < TPBUFSIZE - TPBUFSIZE/4; i++ ) { 00226 j += ybuf[i]; 00227 } 00228 *y = j * (float)2/TPBUFSIZE; // This is the average 00229 // Average the middle half of the X values and report them 00230 j = 0; 00231 for(i = (TPBUFSIZE/4) - 1; i < TPBUFSIZE - TPBUFSIZE/4; i++ ) { 00232 j += xbuf[i]; 00233 } 00234 *x = j * (float)2/TPBUFSIZE; // This is the average 00235 // Tidy up and return 00236 touchready = 1; 00237 sample = 0; // Ready to start on the next set of data samples 00238 } else { 00239 // Buffer not yet full, so do not return any results yet 00240 touchready = 0; 00241 } 00242 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear that TP interrupt flag 00243 } // End of initial if -- data has been read and processed 00244 else 00245 touchready = 0; // Touch Panel "Int" was not set 00246 return touchready; 00247 } 00248 00249 bool RA8875::TouchPanelA2DRaw(loc_t *x, loc_t *y) 00250 { 00251 unsigned char touchready; 00252 00253 if( (ReadCommand(INTC2) & RA8875_INT_TP) ) { // Test for TP Interrupt pending in register INTC2 00254 *y = ReadCommand(TPYH) << 2 | ( (ReadCommand(TPXYL) & 0xC) >> 2 ); // D[9:2] from reg TPYH, D[1:0] from reg TPXYL[3:2] 00255 *x = ReadCommand(TPXH) << 2 | ( (ReadCommand(TPXYL) & 0x3) ); // D[9:2] from reg TPXH, D[1:0] from reg TPXYL[1:0] 00256 WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear that TP interrupt flag 00257 touchready = 1; 00258 } else 00259 touchready = 0; 00260 return touchready; 00261 } 00262 00263 /* The following section is derived from Carlos E. Vidales. 00264 * 00265 * Copyright (c) 2001, Carlos E. Vidales. All rights reserved. 00266 * 00267 * This sample program was written and put in the public domain 00268 * by Carlos E. Vidales. The program is provided "as is" 00269 * without warranty of any kind, either expressed or implied. 00270 * If you choose to use the program within your own products 00271 * you do so at your own risk, and assume the responsibility 00272 * for servicing, repairing or correcting the program should 00273 * it prove defective in any manner. 00274 * You may copy and distribute the program's source code in any 00275 * medium, provided that you also include in each copy an 00276 * appropriate copyright notice and disclaimer of warranty. 00277 * You may also modify this program and distribute copies of 00278 * it provided that you include prominent notices stating 00279 * that you changed the file(s) and the date of any change, 00280 * and that you do not charge any royalties or licenses for 00281 * its use. 00282 * 00283 * This file contains functions that implement calculations 00284 * necessary to obtain calibration factors for a touch screen 00285 * that suffers from multiple distortion effects: namely, 00286 * translation, scaling and rotation. 00287 * 00288 * The following set of equations represent a valid display 00289 * point given a corresponding set of touch screen points: 00290 * 00291 * /- -\ 00292 * /- -\ /- -\ | | 00293 * | | | | | Xs | 00294 * | Xd | | A B C | | | 00295 * | | = | | * | Ys | 00296 * | Yd | | D E F | | | 00297 * | | | | | 1 | 00298 * \- -/ \- -/ | | 00299 * \- -/ 00300 * where: 00301 * (Xd,Yd) represents the desired display point 00302 * coordinates, 00303 * (Xs,Ys) represents the available touch screen 00304 * coordinates, and the matrix 00305 * /- -\ 00306 * |A,B,C| 00307 * |D,E,F| represents the factors used to translate 00308 * \- -/ the available touch screen point values 00309 * into the corresponding display 00310 * coordinates. 00311 * Note that for practical considerations, the utilities 00312 * within this file do not use the matrix coefficients as 00313 * defined above, but instead use the following 00314 * equivalents, since floating point math is not used: 00315 * A = An/Divider 00316 * B = Bn/Divider 00317 * C = Cn/Divider 00318 * D = Dn/Divider 00319 * E = En/Divider 00320 * F = Fn/Divider 00321 * The functions provided within this file are: 00322 * setCalibrationMatrix() - calculates the set of factors 00323 * in the above equation, given 00324 * three sets of test points. 00325 * getDisplayPoint() - returns the actual display 00326 * coordinates, given a set of 00327 * touch screen coordinates. 00328 * translateRawScreenCoordinates() - helper function to transform 00329 * raw screen points into values 00330 * scaled to the desired display 00331 * resolution. 00332 */ 00333 00334 /********************************************************************** 00335 * 00336 * Function: setCalibrationMatrix() 00337 * 00338 * Description: Calling this function with valid input data 00339 * in the display and screen input arguments 00340 * causes the calibration factors between the 00341 * screen and display points to be calculated, 00342 * and the output argument - matrixPtr - to be 00343 * populated. 00344 * 00345 * This function needs to be called only when new 00346 * calibration factors are desired. 00347 * 00348 * 00349 * Argument(s): displayPtr (input) - Pointer to an array of three 00350 * sample, reference points. 00351 * screenPtr (input) - Pointer to the array of touch 00352 * screen points corresponding 00353 * to the reference display points. 00354 * matrixPtr (output) - Pointer to the calibration 00355 * matrix computed for the set 00356 * of points being provided. 00357 * 00358 * 00359 * From the article text, recall that the matrix coefficients are 00360 * resolved to be the following: 00361 * 00362 * 00363 * Divider = (Xs0 - Xs2)*(Ys1 - Ys2) - (Xs1 - Xs2)*(Ys0 - Ys2) 00364 * 00365 * 00366 * 00367 * (Xd0 - Xd2)*(Ys1 - Ys2) - (Xd1 - Xd2)*(Ys0 - Ys2) 00368 * A = --------------------------------------------------- 00369 * Divider 00370 * 00371 * 00372 * (Xs0 - Xs2)*(Xd1 - Xd2) - (Xd0 - Xd2)*(Xs1 - Xs2) 00373 * B = --------------------------------------------------- 00374 * Divider 00375 * 00376 * 00377 * Ys0*(Xs2*Xd1 - Xs1*Xd2) + 00378 * Ys1*(Xs0*Xd2 - Xs2*Xd0) + 00379 * Ys2*(Xs1*Xd0 - Xs0*Xd1) 00380 * C = --------------------------------------------------- 00381 * Divider 00382 * 00383 * 00384 * (Yd0 - Yd2)*(Ys1 - Ys2) - (Yd1 - Yd2)*(Ys0 - Ys2) 00385 * D = --------------------------------------------------- 00386 * Divider 00387 * 00388 * 00389 * (Xs0 - Xs2)*(Yd1 - Yd2) - (Yd0 - Yd2)*(Xs1 - Xs2) 00390 * E = --------------------------------------------------- 00391 * Divider 00392 * 00393 * 00394 * Ys0*(Xs2*Yd1 - Xs1*Yd2) + 00395 * Ys1*(Xs0*Yd2 - Xs2*Yd0) + 00396 * Ys2*(Xs1*Yd0 - Xs0*Yd1) 00397 * F = --------------------------------------------------- 00398 * Divider 00399 * 00400 * 00401 * Return: OK - the calibration matrix was correctly 00402 * calculated and its value is in the 00403 * output argument. 00404 * NOT_OK - an error was detected and the 00405 * function failed to return a valid 00406 * set of matrix values. 00407 * The only time this sample code returns 00408 * NOT_OK is when Divider == 0 00409 * 00410 * 00411 * 00412 * NOTE! NOTE! NOTE! 00413 * 00414 * setCalibrationMatrix() and getDisplayPoint() will do fine 00415 * for you as they are, provided that your digitizer 00416 * resolution does not exceed 10 bits (1024 values). Higher 00417 * resolutions may cause the integer operations to overflow 00418 * and return incorrect values. If you wish to use these 00419 * functions with digitizer resolutions of 12 bits (4096 00420 * values) you will either have to a) use 64-bit signed 00421 * integer variables and math, or b) judiciously modify the 00422 * operations to scale results by a factor of 2 or even 4. 00423 * 00424 */ 00425 RetCode_t RA8875::TouchPanelComputeCalibration(point_t * displayPtr, point_t * screenPtr, tpMatrix_t * matrixPtr) 00426 { 00427 RetCode_t retValue = noerror; 00428 00429 tpMatrix.Divider = ((screenPtr[0].x - screenPtr[2].x) * (screenPtr[1].y - screenPtr[2].y)) - 00430 ((screenPtr[1].x - screenPtr[2].x) * (screenPtr[0].y - screenPtr[2].y)) ; 00431 00432 if( tpMatrix.Divider == 0 ) { 00433 retValue = bad_parameter; 00434 } else { 00435 tpMatrix.An = ((displayPtr[0].x - displayPtr[2].x) * (screenPtr[1].y - screenPtr[2].y)) - 00436 ((displayPtr[1].x - displayPtr[2].x) * (screenPtr[0].y - screenPtr[2].y)) ; 00437 00438 tpMatrix.Bn = ((screenPtr[0].x - screenPtr[2].x) * (displayPtr[1].x - displayPtr[2].x)) - 00439 ((displayPtr[0].x - displayPtr[2].x) * (screenPtr[1].x - screenPtr[2].x)) ; 00440 00441 tpMatrix.Cn = (screenPtr[2].x * displayPtr[1].x - screenPtr[1].x * displayPtr[2].x) * screenPtr[0].y + 00442 (screenPtr[0].x * displayPtr[2].x - screenPtr[2].x * displayPtr[0].x) * screenPtr[1].y + 00443 (screenPtr[1].x * displayPtr[0].x - screenPtr[0].x * displayPtr[1].x) * screenPtr[2].y ; 00444 00445 tpMatrix.Dn = ((displayPtr[0].y - displayPtr[2].y) * (screenPtr[1].y - screenPtr[2].y)) - 00446 ((displayPtr[1].y - displayPtr[2].y) * (screenPtr[0].y - screenPtr[2].y)) ; 00447 00448 tpMatrix.En = ((screenPtr[0].x - screenPtr[2].x) * (displayPtr[1].y - displayPtr[2].y)) - 00449 ((displayPtr[0].y - displayPtr[2].y) * (screenPtr[1].x - screenPtr[2].x)) ; 00450 00451 tpMatrix.Fn = (screenPtr[2].x * displayPtr[1].y - screenPtr[1].x * displayPtr[2].y) * screenPtr[0].y + 00452 (screenPtr[0].x * displayPtr[2].y - screenPtr[2].x * displayPtr[0].y) * screenPtr[1].y + 00453 (screenPtr[1].x * displayPtr[0].y - screenPtr[0].x * displayPtr[1].y) * screenPtr[2].y ; 00454 if (matrixPtr) 00455 memcpy(matrixPtr, &tpMatrix, sizeof(tpMatrix_t)); 00456 } 00457 return( retValue ) ; 00458 } 00459 00460 // #### end of touch panel code additions
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