Diff: Joystick.cpp

Revision:

0:36fb749b83c7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Joystick.cpp	Mon Dec 07 17:24:52 2009 +0000
@@ -0,0 +1,126 @@
+/*
+* N3310LCD. A program to interface mbed with the nuelectronics
+* Nokia 3310 LCD shield from www.nuelectronics.com. Ported from
+* the nuelectronics Arduino code.
+*
+* Copyright (C) <2009> Petras Saduikis <petras@petras.co.uk>
+*
+* This file is part of N3310LCD.
+*
+* N3310LCD is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+* 
+* N3310LCD is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with N3310LCD.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <mbed.h>
+#include "Joystick.h"
+
+//keypad debounce parameter
+#define DEBOUNCE_MAX 15
+#define DEBOUNCE_ON  10
+#define DEBOUNCE_OFF 3
+
+// values correspond to use of a 3.3V supply for the LCD shield.
+const int Joystick::adcKeyVal[NUM_KEYS] = {50,     // LEFT
+                                           200,    // CENTER DEPRESSED
+                                           400,    // DOWN 
+                                           600,    // UP
+                                           800     // RIGHT
+                                           // 1024 CENTER NOT DEPRESSED
+                                           };
+                                           
+Joystick::Joystick(PinName jstick) : joystick(jstick)
+{
+    // reset button arrays
+    for (int i = 0; i < NUM_KEYS; i++)
+    {
+        buttonCount[i] = 0;
+        buttonStatus[i] = 0;
+        buttonFlag[i] = 0;
+    }
+}
+
+int Joystick::getKeyState(int i)
+{
+    int retval = 0;
+    
+    if (i < NUM_KEYS)
+    {
+        retval = buttonFlag[i];
+    }
+    
+    return retval;
+}
+
+void Joystick::resetKeyState(int i)
+{
+    if (i < NUM_KEYS)
+    {
+        buttonFlag[i] = 0;
+    }
+}
+
+void Joystick::updateADCKey()
+{
+    // NOTE: the mbed analog in is 0 - 3.3V, represented as 0.0 - 1.0. It is important 
+    // that the LCD shield is powered from a 3.3V supply in order for the 'right' joystick
+    // key to function correctly.
+    
+    int adcKeyIn = joystick * 1024;    // scale this up so we can use int
+    int keyIn = getKey(adcKeyIn);
+    
+    for (int i = 0; i < NUM_KEYS; i++)
+    {
+        if (keyIn == i)  //one key is pressed 
+        { 
+            if (buttonCount[i] < DEBOUNCE_MAX)
+            {
+                buttonCount[i]++;
+                if (buttonCount[i] > DEBOUNCE_ON)
+                {
+                    if (buttonStatus[i] == 0)
+                    {
+                        buttonFlag[i] = 1;
+                        buttonStatus[i] = 1; //button debounced to 'pressed' status
+                    }
+                }
+            }
+        }
+        else // no button pressed
+        {
+            if (buttonCount[i] > 0)
+            {  
+                buttonFlag[i] = 0;    
+                buttonCount[i]--;
+                if (buttonCount[i] < DEBOUNCE_OFF)
+                {
+                    buttonStatus[i] = 0;   //button debounced to 'released' status
+                }
+            }
+        }
+    }
+}
+  
+// Convert ADC value to key number
+int Joystick::getKey(int input)
+{
+    int k;
+    
+    for (k = 0; k < NUM_KEYS; k++)
+    {
+        if (input < adcKeyVal[k]) return k;
+    }
+    
+    if (k >= NUM_KEYS) k = -1;     // No valid key pressed
+    
+    return k;
+}