Kerry Martin
KSM edits to RA8875
Diff: RA8875_Touch.cpp
- Revision:
- 78:faf49c381591
- Child:
- 79:544eb4964795
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/RA8875_Touch.cpp Sun Dec 28 03:14:35 2014 +0000
@@ -0,0 +1,406 @@
+/// This file contains the RA8875 Touch panel methods.
+///
+
+#include "RA8875.h"
+
+// ### Touch Panel support code additions begin here
+
+RetCode_t RA8875::TouchPanelInit(void)
+{
+ //TPCR0: Set enable bit, default sample time, wakeup, and ADC clock
+ WriteCommand(TPCR0, TP_ENABLE | TP_ADC_SAMPLE_DEFAULT_CLKS | TP_ADC_CLKDIV_DEFAULT);
+ // TPCR1: Set auto/manual, Ref voltage, debounce, manual mode params
+ WriteCommand(TPCR1, TP_MODE_DEFAULT | TP_DEBOUNCE_DEFAULT);
+ WriteCommand(INTC1, ReadCommand(INTC1) | RA8875_INT_TP); // reg INTC1: Enable Touch Panel Interrupts (D2 = 1)
+ WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear any TP interrupt flag
+ return noerror;
+}
+
+RetCode_t RA8875::TouchPanelInit(uint8_t bTpEnable, uint8_t bTpAutoManual, uint8_t bTpDebounce, uint8_t bTpManualMode, uint8_t bTpAdcClkDiv, uint8_t bTpAdcSampleTime)
+{
+ // Parameter bounds check
+ if( \
+ !(bTpEnable == TP_ENABLE || bTpEnable == TP_ENABLE) || \
+ !(bTpAutoManual == TP_MODE_AUTO || bTpAutoManual == TP_MODE_MANUAL) || \
+ !(bTpDebounce == TP_DEBOUNCE_OFF || bTpDebounce == TP_DEBOUNCE_ON) || \
+ !(bTpManualMode <= TP_MANUAL_LATCH_Y) || \
+ !(bTpAdcClkDiv <= TP_ADC_CLKDIV_128) || \
+ !(bTpAdcSampleTime <= TP_ADC_SAMPLE_65536_CLKS) \
+ ) return bad_parameter;
+ // Construct the config byte for TPCR0 and write them
+ WriteCommand(TPCR0, bTpEnable | bTpAdcClkDiv | bTpAdcSampleTime); // Note: Wakeup is never enabled
+ // Construct the config byte for TPCR1 and write them
+ WriteCommand(TPCR1, bTpManualMode | bTpDebounce | bTpManualMode); // Note: Always uses internal Vref.
+ // Set up the interrupt flag and enable bits
+ WriteCommand(INTC1, ReadCommand(INTC1) | RA8875_INT_TP); // reg INTC1: Enable Touch Panel Interrupts (D2 = 1)
+ WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear any TP interrupt flag
+ return noerror;
+}
+
+unsigned char RA8875::TouchPanelRead(loc_t *x, loc_t *y)
+{
+ unsigned char touchready;
+ static int xbuf[TPBUFSIZE], ybuf[TPBUFSIZE], sample = 0;
+ int i, j, temp;
+
+ if( (ReadCommand(INTC2) & RA8875_INT_TP) ) { // Test for TP Interrupt pending in register INTC2
+ // Get the next data samples
+ ybuf[sample] = ReadCommand(TPYH) << 2 | ( (ReadCommand(TPXYL) & 0xC) >> 2 ); // D[9:2] from reg TPYH, D[1:0] from reg TPXYL[3:2]
+ xbuf[sample] = ReadCommand(TPXH) << 2 | ( (ReadCommand(TPXYL) & 0x3) ); // D[9:2] from reg TPXH, D[1:0] from reg TPXYL[1:0]
+ // Check for a complete set
+ if(++sample == TPBUFSIZE) {
+ // Buffers are full, so process them using Finn's method described in Analog Dialogue No. 44, Feb 2010
+ // This requires sorting the samples in order of size, then discarding the top 25% and
+ // bottom 25% as noise spikes. Finally, the middle 50% of the values are averaged to
+ // reduce Gaussian noise.
+
+ // Sort the Y buffer using an Insertion Sort
+ for(i = 1; i <= TPBUFSIZE; i++) {
+ temp = ybuf[i];
+ j = i;
+ while( j && (ybuf[j-1] > temp) ) {
+ ybuf[j] = ybuf[j-1];
+ j = j-1;
+ }
+ ybuf[j] = temp;
+ } // End of Y sort
+ // Sort the X buffer the same way
+ for(i = 1; i <= TPBUFSIZE; i++) {
+ temp = xbuf[i];
+ j = i;
+ while( j && (xbuf[j-1] > temp) ) {
+ xbuf[j] = xbuf[j-1];
+ j = j-1;
+ }
+ xbuf[j] = temp;
+ } // End of X sort
+ // Average the middle half of the Y values and report them
+ j = 0;
+ for(i = (TPBUFSIZE/4) - 1; i < TPBUFSIZE - TPBUFSIZE/4; i++ ) {
+ j += ybuf[i];
+ }
+ *y = j * (float)2/TPBUFSIZE; // This is the average
+ // Average the middle half of the X values and report them
+ j = 0;
+ for(i = (TPBUFSIZE/4) - 1; i < TPBUFSIZE - TPBUFSIZE/4; i++ ) {
+ j += xbuf[i];
+ }
+ *x = j * (float)2/TPBUFSIZE; // This is the average
+ // Tidy up and return
+ touchready = 1;
+ sample = 0; // Ready to start on the next set of data samples
+ } else {
+ // Buffer not yet full, so do not return any results yet
+ touchready = 0;
+ }
+ WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear that TP interrupt flag
+ } // End of initial if -- data has been read and processed
+ else
+ touchready = 0; // Touch Panel "Int" was not set
+ return touchready;
+}
+
+unsigned char RA8875::TouchPanelReadRaw(loc_t *x, loc_t *y)
+{
+ unsigned char touchready;
+
+ if( (ReadCommand(INTC2) & RA8875_INT_TP) ) { // Test for TP Interrupt pending in register INTC2
+ *y = ReadCommand(TPYH) << 2 | ( (ReadCommand(TPXYL) & 0xC) >> 2 ); // D[9:2] from reg TPYH, D[1:0] from reg TPXYL[3:2]
+ *x = ReadCommand(TPXH) << 2 | ( (ReadCommand(TPXYL) & 0x3) ); // D[9:2] from reg TPXH, D[1:0] from reg TPXYL[1:0]
+ WriteCommand(INTC2, RA8875_INT_TP); // reg INTC2: Clear that TP interrupt flag
+ touchready = 1;
+ } else
+ touchready = 0;
+ return touchready;
+}
+
+/* The following section is derived from Carlos E. Vidales.
+ *
+ * Copyright (c) 2001, Carlos E. Vidales. All rights reserved.
+ *
+ * This sample program was written and put in the public domain
+ * by Carlos E. Vidales. The program is provided "as is"
+ * without warranty of any kind, either expressed or implied.
+ * If you choose to use the program within your own products
+ * you do so at your own risk, and assume the responsibility
+ * for servicing, repairing or correcting the program should
+ * it prove defective in any manner.
+ * You may copy and distribute the program's source code in any
+ * medium, provided that you also include in each copy an
+ * appropriate copyright notice and disclaimer of warranty.
+ * You may also modify this program and distribute copies of
+ * it provided that you include prominent notices stating
+ * that you changed the file(s) and the date of any change,
+ * and that you do not charge any royalties or licenses for
+ * its use.
+ *
+ * This file contains functions that implement calculations
+ * necessary to obtain calibration factors for a touch screen
+ * that suffers from multiple distortion effects: namely,
+ * translation, scaling and rotation.
+ *
+ * The following set of equations represent a valid display
+ * point given a corresponding set of touch screen points:
+ *
+ * /- -\
+ * /- -\ /- -\ | |
+ * | | | | | Xs |
+ * | Xd | | A B C | | |
+ * | | = | | * | Ys |
+ * | Yd | | D E F | | |
+ * | | | | | 1 |
+ * \- -/ \- -/ | |
+ * \- -/
+ * where:
+ * (Xd,Yd) represents the desired display point
+ * coordinates,
+ * (Xs,Ys) represents the available touch screen
+ * coordinates, and the matrix
+ * /- -\
+ * |A,B,C|
+ * |D,E,F| represents the factors used to translate
+ * \- -/ the available touch screen point values
+ * into the corresponding display
+ * coordinates.
+ * Note that for practical considerations, the utilities
+ * within this file do not use the matrix coefficients as
+ * defined above, but instead use the following
+ * equivalents, since floating point math is not used:
+ * A = An/Divider
+ * B = Bn/Divider
+ * C = Cn/Divider
+ * D = Dn/Divider
+ * E = En/Divider
+ * F = Fn/Divider
+ * The functions provided within this file are:
+ * setCalibrationMatrix() - calculates the set of factors
+ * in the above equation, given
+ * three sets of test points.
+ * getDisplayPoint() - returns the actual display
+ * coordinates, given a set of
+ * touch screen coordinates.
+ * translateRawScreenCoordinates() - helper function to transform
+ * raw screen points into values
+ * scaled to the desired display
+ * resolution.
+ */
+
+/**********************************************************************
+ *
+ * Function: setCalibrationMatrix()
+ *
+ * Description: Calling this function with valid input data
+ * in the display and screen input arguments
+ * causes the calibration factors between the
+ * screen and display points to be calculated,
+ * and the output argument - matrixPtr - to be
+ * populated.
+ *
+ * This function needs to be called only when new
+ * calibration factors are desired.
+ *
+ *
+ * Argument(s): displayPtr (input) - Pointer to an array of three
+ * sample, reference points.
+ * screenPtr (input) - Pointer to the array of touch
+ * screen points corresponding
+ * to the reference display points.
+ * matrixPtr (output) - Pointer to the calibration
+ * matrix computed for the set
+ * of points being provided.
+ *
+ *
+ * From the article text, recall that the matrix coefficients are
+ * resolved to be the following:
+ *
+ *
+ * Divider = (Xs0 - Xs2)*(Ys1 - Ys2) - (Xs1 - Xs2)*(Ys0 - Ys2)
+ *
+ *
+ *
+ * (Xd0 - Xd2)*(Ys1 - Ys2) - (Xd1 - Xd2)*(Ys0 - Ys2)
+ * A = ---------------------------------------------------
+ * Divider
+ *
+ *
+ * (Xs0 - Xs2)*(Xd1 - Xd2) - (Xd0 - Xd2)*(Xs1 - Xs2)
+ * B = ---------------------------------------------------
+ * Divider
+ *
+ *
+ * Ys0*(Xs2*Xd1 - Xs1*Xd2) +
+ * Ys1*(Xs0*Xd2 - Xs2*Xd0) +
+ * Ys2*(Xs1*Xd0 - Xs0*Xd1)
+ * C = ---------------------------------------------------
+ * Divider
+ *
+ *
+ * (Yd0 - Yd2)*(Ys1 - Ys2) - (Yd1 - Yd2)*(Ys0 - Ys2)
+ * D = ---------------------------------------------------
+ * Divider
+ *
+ *
+ * (Xs0 - Xs2)*(Yd1 - Yd2) - (Yd0 - Yd2)*(Xs1 - Xs2)
+ * E = ---------------------------------------------------
+ * Divider
+ *
+ *
+ * Ys0*(Xs2*Yd1 - Xs1*Yd2) +
+ * Ys1*(Xs0*Yd2 - Xs2*Yd0) +
+ * Ys2*(Xs1*Yd0 - Xs0*Yd1)
+ * F = ---------------------------------------------------
+ * Divider
+ *
+ *
+ * Return: OK - the calibration matrix was correctly
+ * calculated and its value is in the
+ * output argument.
+ * NOT_OK - an error was detected and the
+ * function failed to return a valid
+ * set of matrix values.
+ * The only time this sample code returns
+ * NOT_OK is when Divider == 0
+ *
+ *
+ *
+ * NOTE! NOTE! NOTE!
+ *
+ * setCalibrationMatrix() and getDisplayPoint() will do fine
+ * for you as they are, provided that your digitizer
+ * resolution does not exceed 10 bits (1024 values). Higher
+ * resolutions may cause the integer operations to overflow
+ * and return incorrect values. If you wish to use these
+ * functions with digitizer resolutions of 12 bits (4096
+ * values) you will either have to a) use 64-bit signed
+ * integer variables and math, or b) judiciously modify the
+ * operations to scale results by a factor of 2 or even 4.
+ *
+ */
+RetCode_t RA8875::TouchPanelCalibrate(point_t * displayPtr, point_t * screenPtr, tpMatrix_t * matrixPtr)
+{
+ RetCode_t retValue = noerror;
+
+ tpMatrix.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( tpMatrix.Divider == 0 ) {
+ retValue = bad_parameter;
+ } else {
+ tpMatrix.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)) ;
+
+ tpMatrix.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)) ;
+
+ tpMatrix.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 ;
+
+ tpMatrix.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)) ;
+
+ tpMatrix.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)) ;
+
+ tpMatrix.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 ;
+ if (matrixPtr)
+ memcpy(matrixPtr, &tpMatrix, sizeof(tpMatrix_t));
+ }
+ return( retValue ) ;
+}
+
+/**********************************************************************
+ *
+ * Function: getDisplayPoint()
+ *
+ * Description: Given a valid set of calibration factors and a point
+ * value reported by the touch screen, this function
+ * calculates and returns the true (or closest to true)
+ * display point below the spot where the touch screen
+ * was touched.
+ *
+ *
+ *
+ * Argument(s): displayPtr (output) - Pointer to the calculated
+ * (true) display point.
+ * screenPtr (input) - Pointer to the reported touch
+ * screen point.
+ * matrixPtr (input) - Pointer to calibration factors
+ * matrix previously calculated
+ * from a call to
+ * setCalibrationMatrix()
+ *
+ *
+ * The function simply solves for Xd and Yd by implementing the
+ * computations required by the translation matrix.
+ *
+ * /- -\
+ * /- -\ /- -\ | |
+ * | | | | | Xs |
+ * | Xd | | A B C | | |
+ * | | = | | * | Ys |
+ * | Yd | | D E F | | |
+ * | | | | | 1 |
+ * \- -/ \- -/ | |
+ * \- -/
+ *
+ * It must be kept brief to avoid consuming CPU cycles.
+ *
+ * Return: OK - the display point was correctly calculated
+ * and its value is in the output argument.
+ * NOT_OK - an error was detected and the function
+ * failed to return a valid point.
+ *
+ * NOTE! NOTE! NOTE!
+ *
+ * setCalibrationMatrix() and getDisplayPoint() will do fine
+ * for you as they are, provided that your digitizer
+ * resolution does not exceed 10 bits (1024 values). Higher
+ * resolutions may cause the integer operations to overflow
+ * and return incorrect values. If you wish to use these
+ * functions with digitizer resolutions of 12 bits (4096
+ * values) you will either have to a) use 64-bit signed
+ * integer variables and math, or b) judiciously modify the
+ * operations to scale results by a factor of 2 or even 4.
+ *
+ */
+RetCode_t RA8875::TouchPanelPoint(point_t * TouchPoint)
+{
+ RetCode_t retValue = no_touch;
+ point_t screenpoint = {0, 0};
+
+ if (TouchPanelRead(&screenpoint.x, &screenpoint.y)) {
+ retValue = touch;
+ if (tpMatrix.Divider != 0 ) {
+ /* Operation order is important since we are doing integer */
+ /* math. Make sure you add all terms together before */
+ /* dividing, so that the remainder is not rounded off */
+ /* prematurely. */
+ TouchPoint->x = ( (tpMatrix.An * screenpoint.x) +
+ (tpMatrix.Bn * screenpoint.y) +
+ tpMatrix.Cn
+ ) / tpMatrix.Divider ;
+
+ TouchPoint->y = ( (tpMatrix.Dn * screenpoint.x) +
+ (tpMatrix.En * screenpoint.y) +
+ tpMatrix.Fn
+ ) / tpMatrix.Divider ;
+ } else {
+ retValue = bad_parameter ;
+ }
+ }
+ return( retValue );
+}
+
+
+RetCode_t RA8875::TouchPanelSetMatrix(tpMatrix_t * matrixPtr)
+{
+ if (matrixPtr == NULL || matrixPtr->Divider == 0)
+ return bad_parameter;
+ memcpy(&tpMatrix, matrixPtr, sizeof(tpMatrix_t));
+ return noerror;
+}
+
+// #### end of touch panel code additions