Diff: TouchPanel.cpp

Revision:

0:e38c94c549f4

Child:

1:007113101ef7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TouchPanel.cpp	Tue Jan 28 10:55:53 2014 +0000
@@ -0,0 +1,142 @@
+/***************************************************************************//**
+ * @file   TouchPanel.cpp
+ * @brief  Implementation of the touch panel driver for the
+ *         TFT color display MI0283QT-9A (320x240).
+ * @author Mario Poneder
+ * @date   28/01/2013
+*******************************************************************************/
+
+/******************************************************************************/
+/***************************** Include Files **********************************/
+/******************************************************************************/
+#include "TouchPanel.h"
+
+/***************************************************************************//**
+ * @brief Creates an instance of the TouchPanel class. Each of the following
+ *        pins has to be connected to an AnalogIn pin.
+ *
+ * @param xPos  X+
+ * @param xNeg  X-
+ * @param yPos  Y+
+ * @param yNeg  Y-
+*******************************************************************************/
+TouchPanel::TouchPanel(PinName xPos, PinName xNeg, PinName yPos, PinName yNeg)
+{
+    this->xPos = xPos;
+    this->xNeg = xNeg;
+    this->yPos = yPos;
+    this->yNeg = yNeg;
+    this->xy = true;
+}
+
+/***************************************************************************//**
+ * @brief Calls the PollPanel method in specified intervals.
+ *
+ * @param touchCallbackFunction     Pointer to the touch callback function,
+ *                                  which has to take the parameters 'x' and
+ *                                  'y' and gets called when a touch was detected.
+ *
+ * @return None.
+*******************************************************************************/
+void TouchPanel::SetTouchCallbackFunction(pTouchCallback_t touchCallbackFunction)
+{
+    this->touchCallbackFunction = touchCallbackFunction;
+    this->PrepareYRead();
+    this->pollPanelTicker.attach(this, &TouchPanel::PollPanel, POLLING_INVERVAL);
+}
+
+/***************************************************************************//**
+ * @brief Prepares the touch panel and the software in order read the
+ *        Y coordinate.
+ *
+ * @return None.
+*******************************************************************************/
+void TouchPanel::PrepareYRead(void)
+{
+    delete yPosOut;
+    delete yNegOut;
+    delete xPosIn;
+    delete xNegIn;
+    xPosOut = new DigitalOut(xPos);
+    xNegOut = new DigitalOut(xNeg);
+    xPosOut->write(1);
+    xNegOut->write(0);
+    yPosIn = new AnalogIn(yPos);
+    yNegIn = new AnalogIn(yNeg);
+}
+
+/***************************************************************************//**
+ * @brief Prepares the touch panel and the software in order read the
+ *        X coordinate.
+ *
+ * @return None.
+*******************************************************************************/
+void TouchPanel::PrepareXRead(void)
+{
+    delete xPosOut;
+    delete xNegOut;
+    delete yPosIn;
+    delete yNegIn;
+    yPosOut = new DigitalOut(yPos);
+    yNegOut = new DigitalOut(yNeg);
+    yPosOut->write(1);
+    yNegOut->write(0);
+    xPosIn = new AnalogIn(xPos);
+    xNegIn = new AnalogIn(xNeg);
+}
+
+/***************************************************************************//**
+ * @brief Alternately reads the touch panel's X or Y coordinate and calls the
+ *        touch callback function, which has to take the parameters
+ *        'x' and 'y', when a touch was detected.
+ *
+ * @return None.
+*******************************************************************************/
+void TouchPanel::PollPanel(void)
+{
+    static float yp, yn, xp, xn;
+    static unsigned short x = NO_TOUCH_VAL;
+    static unsigned short y = NO_TOUCH_VAL;
+    static bool newTouch = true;
+
+    if(this->xy) {
+        yp = yPosIn->read();
+        yn = yNegIn->read();
+        this->PrepareXRead();
+        if(fabs(yp - yn) < TOUCH_THRESHOLD) {
+            yp = HEIGHT * (1 - (yp - BOTTOM) / (TOP - BOTTOM));
+            if(yp < 0) {
+                y = 0;
+            } else if(yp > HEIGHT) {
+                y = HEIGHT;
+            } else {
+                y = yp;
+            }
+        } else {
+            y = NO_TOUCH_VAL;
+            newTouch = true;
+        }
+    } else {
+        xp = xPosIn->read();
+        xn = xNegIn->read();
+        this->PrepareYRead();
+        if(fabs(xp - xn) < TOUCH_THRESHOLD) {
+            xp = WIDTH * (xp - LEFT) / (RIGHT - LEFT);
+            if(xp < 0) {
+                x = 0;
+            } else if(xp > WIDTH) {
+                x = WIDTH;
+            } else {
+                x = xp;
+            }
+        } else {
+            x = NO_TOUCH_VAL;
+            newTouch = true;
+        }
+    }
+    this->xy = !this->xy;
+    if(x != NO_TOUCH_VAL && y != NO_TOUCH_VAL && newTouch && x > 0) {
+        newTouch = false;
+        this->touchCallbackFunction(x, y);
+    }
+}