ELEC2645 (2015/16) / ishtendo_vI

My Embedded Systems Project Ihsian Mulla (el14imfm@leeds.ac.uk 200839613

joystick.cpp@0:f79fe9dc65ee, 2016-05-04 (annotated)

Committer:
Ihsianmulla
Date:
Wed May 04 13:01:09 2016 +0000
Revision:
0:f79fe9dc65ee
Joystick Functions

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Ihsianmulla 0:f79fe9dc65ee 1 /** Temperature Sensor Functions
Ihsianmulla 0:f79fe9dc65ee 2 * Used for printing and updating the temperature at 1Hz with unit conversion capabilities
Ihsianmulla 0:f79fe9dc65ee 3 @file joystick.cpp
Ihsianmulla 0:f79fe9dc65ee 4 @brief contains functions for joystick update/calibration and direction names with specification
Ihsianmulla 0:f79fe9dc65ee 5 @author Craig Evans
Ihsianmulla 0:f79fe9dc65ee 6 @date May 2016
Ihsianmulla 0:f79fe9dc65ee 7 */
Ihsianmulla 0:f79fe9dc65ee 8
Ihsianmulla 0:f79fe9dc65ee 9 #include "joystick.h"
Ihsianmulla 0:f79fe9dc65ee 10
Ihsianmulla 0:f79fe9dc65ee 11 extern Joystick joystick;
Ihsianmulla 0:f79fe9dc65ee 12
Ihsianmulla 0:f79fe9dc65ee 13 void calibrateJoystick()
Ihsianmulla 0:f79fe9dc65ee 14 {
Ihsianmulla 0:f79fe9dc65ee 15 button.mode(PullDown);// additional pull down for external button
Ihsianmulla 0:f79fe9dc65ee 16 Jbutton.mode(PullDown);
Ihsianmulla 0:f79fe9dc65ee 17 // must not move during calibration
Ihsianmulla 0:f79fe9dc65ee 18 joystick.x0 = xPot; // initial positions in the range 0.0 to 1.0 (0.5 if centred exactly)
Ihsianmulla 0:f79fe9dc65ee 19 joystick.y0 = yPot;
Ihsianmulla 0:f79fe9dc65ee 20 }
Ihsianmulla 0:f79fe9dc65ee 21
Ihsianmulla 0:f79fe9dc65ee 22 Joystick return_data(){
Ihsianmulla 0:f79fe9dc65ee 23 return joystick;
Ihsianmulla 0:f79fe9dc65ee 24 }
Ihsianmulla 0:f79fe9dc65ee 25 void updateJoystick()
Ihsianmulla 0:f79fe9dc65ee 26 {
Ihsianmulla 0:f79fe9dc65ee 27 // read current joystick values relative to calibrated values (in range -0.5 to 0.5, 0.0 is centred)
Ihsianmulla 0:f79fe9dc65ee 28 joystick.x = xPot - joystick.x0;
Ihsianmulla 0:f79fe9dc65ee 29 joystick.y = yPot - joystick.y0;
Ihsianmulla 0:f79fe9dc65ee 30 // read button state
Ihsianmulla 0:f79fe9dc65ee 31 joystick.button = button;
Ihsianmulla 0:f79fe9dc65ee 32
Ihsianmulla 0:f79fe9dc65ee 33 // calculate direction depending on x,y values
Ihsianmulla 0:f79fe9dc65ee 34 // tolerance allows a little lee-way in case joystick not exactly in the stated direction
Ihsianmulla 0:f79fe9dc65ee 35 if ( fabs(joystick.y) < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
Ihsianmulla 0:f79fe9dc65ee 36 joystick.direction = CENTRE;
Ihsianmulla 0:f79fe9dc65ee 37 } else if ( joystick.y > DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
Ihsianmulla 0:f79fe9dc65ee 38 joystick.direction = UP;
Ihsianmulla 0:f79fe9dc65ee 39 } else if ( joystick.y < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
Ihsianmulla 0:f79fe9dc65ee 40 joystick.direction = DOWN;
Ihsianmulla 0:f79fe9dc65ee 41 } else if ( joystick.x > DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) {
Ihsianmulla 0:f79fe9dc65ee 42 joystick.direction = RIGHT;
Ihsianmulla 0:f79fe9dc65ee 43 } else if ( joystick.x < DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) {
Ihsianmulla 0:f79fe9dc65ee 44 joystick.direction = LEFT;
Ihsianmulla 0:f79fe9dc65ee 45 } else {
Ihsianmulla 0:f79fe9dc65ee 46 joystick.direction = UNKNOWN;
Ihsianmulla 0:f79fe9dc65ee 47 }
Ihsianmulla 0:f79fe9dc65ee 48
Ihsianmulla 0:f79fe9dc65ee 49 }