Revision 0:f79fe9dc65ee, committed 2016-05-04

Comitter:

Ihsianmulla

Date:

Wed May 04 13:01:09 2016 +0000

Commit message:

Joystick Functions

Changed in this revision

diff -r 000000000000 -r f79fe9dc65ee joystick.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/joystick.cpp	Wed May 04 13:01:09 2016 +0000
@@ -0,0 +1,49 @@
+/** Temperature Sensor Functions
+* Used for printing and updating the temperature at 1Hz with unit conversion capabilities
+@file joystick.cpp
+@brief contains functions for joystick update/calibration and direction names with specification
+@author Craig Evans
+@date May 2016
+*/
+
+#include "joystick.h"
+
+extern Joystick joystick;
+
+void calibrateJoystick()
+{
+    button.mode(PullDown);// additional pull down for external button
+    Jbutton.mode(PullDown);
+    // must not move during calibration
+    joystick.x0 = xPot;  // initial positions in the range 0.0 to 1.0 (0.5 if centred exactly)
+    joystick.y0 = yPot;
+}
+
+Joystick return_data(){
+    return joystick;
+}
+void updateJoystick()
+{
+    // read current joystick values relative to calibrated values (in range -0.5 to 0.5, 0.0 is centred)
+    joystick.x = xPot - joystick.x0;
+    joystick.y = yPot - joystick.y0;
+    // read button state
+    joystick.button = button;
+
+    // calculate direction depending on x,y values
+    // tolerance allows a little lee-way in case joystick not exactly in the stated direction
+    if ( fabs(joystick.y) < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
+        joystick.direction = CENTRE;
+    } else if ( joystick.y > DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
+        joystick.direction = UP;
+    } else if ( joystick.y < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
+        joystick.direction = DOWN;
+    } else if ( joystick.x > DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) {
+        joystick.direction = RIGHT;
+    } else if ( joystick.x < DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) {
+        joystick.direction = LEFT;
+    } else {
+        joystick.direction = UNKNOWN;
+    }
+
+}
\ No newline at end of file

diff -r 000000000000 -r f79fe9dc65ee joystick.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/joystick.h	Wed May 04 13:01:09 2016 +0000
@@ -0,0 +1,47 @@
+/** Joystick Functions
+* Used for reading and updating the joystick position and value for its button.
+@file joystick.h
+@brief
+@brief
+@author Craig Evans
+@date April 2016
+*/
+#ifndef _JOYSTICK_H_
+
+#define _JOYSTICK_H_
+
+#define DIRECTION_TOLERANCE 0.25L // change this to alter tolerance of joystick direction
+#include "mbed.h"
+extern InterruptIn button;
+extern AnalogIn xPot;
+extern AnalogIn yPot;
+extern DigitalIn Jbutton;
+extern Ticker pollJoystick;
+
+enum DirectionName {
+    UP,
+    DOWN,
+    LEFT,
+    RIGHT,
+    CENTRE,
+    UNKNOWN
+};
+
+typedef struct JoyStick Joystick;
+struct JoyStick {
+    float x;    // current x value
+    float x0;   // 'centred' x value
+    float y;    // current y value
+    float y0;   // 'centred' y value
+    int button; // button state (assume pull-down used, so 1 = pressed, 0 = unpressed)
+    DirectionName direction;  // current direction
+};
+
+
+
+// function prototypes
+extern void calibrateJoystick();
+extern void updateJoystick();
+extern Joystick return_data();
+
+#endif
\ No newline at end of file