Revision 0:9c486d50434e, committed 2010-09-28

Comitter:

alex89_2

Date:

Tue Sep 28 14:59:57 2010 +0000

Child:

1:e55694d8a418

Commit message:

Release to public

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Joystick.cpp	Tue Sep 28 14:59:57 2010 +0000
@@ -0,0 +1,98 @@
+#include "Joystick.h"
+
+AnalogIn hin(p19);
+AnalogIn vin(p18);
+
+joyhv last = {0.5,0.5};
+
+double scaleb(double min, double max, double bmin, double bmax, double num){
+    double shifted = num + (bmin - min);    //shifted bmin down to min
+    return (shifted - min) * (bmax-bmin)/(max-min) + min; //scaled bmax to max
+}
+
+double doscale(double pos){
+    double min, max, midmin, midmax, scaled;
+    
+    min = 0.087;
+    max = 0.98;
+    
+    midmin = 0.51;
+    midmax = 0.56;
+
+    
+    if(pos < midmin){           // lower than 0.5 tolerance - backwards
+        scaled = scaleb(min, midmin, 0, 0.5, pos);
+    } else if (pos > midmax){   //greater than 0.5 tolerance - forwards
+        scaled = scaleb(midmax, max, 0.5, 1, pos);
+    } else {
+        scaled = 0.5;
+    }
+    
+    //check if out of bounds [0,1]
+    
+    if(scaled < 0)
+        scaled = 0;
+    
+    if(scaled > 1)
+        scaled = 1;
+    
+    return scaled;
+}
+
+
+double dofilter(double last, double num, double factor){
+
+    return last*factor + num*(1-factor);
+
+}
+
+Joystick::Joystick(PinName b, PinName h, PinName v) : _b(b), _h(h), _v(v) {
+}
+
+Joystick::operator joyhv (){
+    joyhv data;
+    data.v = _v.read();
+    data.h = _h.read();
+    return data;
+}
+
+double Joystick::getV (){
+    return _v.read();
+}
+
+double Joystick::getH (){
+    return _h.read();
+}
+
+void Joystick::rise (void (*fptr)(void)){ 
+    _b.rise(fptr);
+}
+
+void Joystick::fall (void (*fptr)(void)){
+    _b.fall(fptr);
+}
+
+//simple filtering
+joyhv Joystick::filter(joyhv read, double factor){
+
+    joyhv filtered = {0.5,0.5};
+    
+    filtered.v = dofilter(last.v, read.v, factor);
+    filtered.h = dofilter(last.h, read.h, factor);
+    
+    last.v = filtered.v;
+    last.h = filtered.h;
+    
+    return filtered;
+}
+
+joyhv Joystick::scale(joyhv read){
+    
+    joyhv scaled = {0.5,0.5};
+    
+    scaled.v = doscale(read.v);
+    scaled.h = doscale(read.h);
+    
+    return scaled;
+    
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Joystick.h	Tue Sep 28 14:59:57 2010 +0000
@@ -0,0 +1,96 @@
+//remove repetition
+#ifndef MBED_JOYSTICK_H
+#define MBED_JOYSTICK_H
+
+//required to use mbed functions
+#include "mbed.h"
+
+struct joyhv {
+    double h;
+    double v;
+};
+
+/* Class: Joystick
+ * Used for reading from an analog joystick
+ *
+ * Example:
+ * > #include "mbed.h"
+ * > Joystick joy(p20, p19, p18);
+ */
+ 
+class Joystick {
+public:
+    /* Constructor: Joystick
+     *  
+     *
+     * Variables: 
+     * b - DigitalIn pin for button
+     * h - AnalogIn pin for horizontal 
+     * v - AnalogIn pin for vertical 
+     */ 
+    Joystick(PinName b, PinName h, PinName v);
+    
+    /* Function: read
+     * Read the joystick position, represented as a joyhv value - h and v are doubles in the range [0.0, 1.0]
+     *
+     * Variables:
+     *  returns - A structure of two double values representing the position of the joystick,
+     *            measured as a percentage vertically (joyhv.v) or horizontally (joyhv.h)
+     */
+    joyhv read();
+
+    /* Function: getV
+     * Read the joystick's vertical position, represented as a double value in the range [0.0, 1.0]
+     *
+     * Variables:
+     *  returns - A double values representing the vertical position of the joystick,
+     *            measured as a percentage  
+     */
+    double getV();
+    
+    /* Function: getH
+     * Read the joystick's horizontal position, represented as a double value in the range [0.0, 1.0]
+     *
+     * Variables:
+     *  returns - A double values representing the horizontal position of the joystick,
+     *            measured as a percentage  
+     */
+    double getH();
+    
+    /* Function: rise
+     *  Attach a function to call when a rising edge occurs on the button input
+     *
+     * Variables:
+     *  fptr - A pointer to a void function, or 0 to set as none
+     */
+    void rise (void (*fptr)(void));
+    
+    /* Function: fall
+     *  Attach a function to call when a falling edge occurs on the button input
+     *
+     * Variables:
+     *  fptr - A pointer to a void function, or 0 to set as none
+     */
+    void fall (void (*fptr)(void));
+    
+    /* Function: operator joyhv
+     *  An operator shorthand for <read()>
+     *
+     * The joyhv() operator can be used as a shorthand for <read()> to simplify common code sequences
+     *
+     */
+    operator joyhv ();
+    
+        
+    joyhv scale(joyhv read);
+    joyhv filter(joyhv read, double factor);
+
+    
+private:
+    InterruptIn _b;
+    AnalogIn _h;
+    AnalogIn _v;
+};
+
+
+#endif
\ No newline at end of file