Joystick.cpp

00001 /**
00002 @file Joystick.cpp
00003 
00004 @brief Member functions implementations
00005 @brief Fixed button
00006 
00007 */
00008 #include "Joystick.h"
00009 #include "mbed.h"
00010 
00011 Joystick::Joystick(PinName x_axis_pin, PinName y_axis_pin, PinName button_pin)
00012 {
00013     x_axis_ = new AnalogIn(x_axis_pin);
00014     y_axis_ = new AnalogIn(y_axis_pin);
00015     button_ = new DigitalIn(button_pin);
00016 }
00017 
00018 Joystick::~Joystick()
00019 {
00020     delete x_axis_;
00021     delete y_axis_;
00022     delete button_;
00023 }
00024 
00025 void Joystick::init()
00026 {
00027     //Sets up the button ISR
00028     button_->mode(PullUp);
00029     //Initalises the vairables and flags
00030     x_offset_ = 0;
00031     y_offset_ = 0;
00032     g_button_flag_ = 0;
00033 
00034     //Samples the joystick 5 times and takes an average to get the offset
00035     float x_sum = 0;
00036     float y_sum = 0;
00037 
00038     for (int i = 0; i < 5; ++i) {
00039         x_sum += x_axis_->read();
00040         y_sum += y_axis_->read();
00041     }
00042 
00043     x_offset_ = 0.5f - x_sum/5.0f;
00044     y_offset_ = 0.5f - y_sum/5.0f;
00045 }
00046 
00047 float Joystick::GetXValue()
00048 {
00049 
00050     float x_sum = 0;
00051     //Iterates 5 times and calculates an average
00052     for (int i = 0; i < 5; ++i) {
00053         x_sum += x_axis_->read();
00054     }
00055 
00056     float x_value = x_sum/5.0f + x_offset_;
00057 
00058     //Caps the value for the POT between 0 and 1
00059     if (x_value < 0.0f) {
00060         return 0;
00061     } else if (x_value > 1.0f) {
00062         return 1;
00063     } else {
00064         return x_value;
00065     }
00066 }
00067 
00068 float Joystick::GetYValue()
00069 {
00070 
00071     float y_sum = 0;
00072     //Iterates 5 times and calculates an average
00073     for (int i = 0; i < 5; ++i) {
00074         y_sum += y_axis_->read();
00075     }
00076 
00077     float y_value = y_sum/5.0f + y_offset_;
00078 
00079     //Caps the value for the POT between 0 and 1
00080     if (y_value < 0.0f) {
00081         return 0;
00082     } else if (y_value > 1.0f) {
00083         return 1;
00084     } else {
00085         return y_value;
00086     }
00087 }
00088 
00089 bool Joystick::get_button_flag()
00090 {
00091     g_button_flag_ = button_ -> read();
00092         return g_button_flag_;
00093 }