Diff: Gamepad/Gamepad.cpp

Revision:

5:e3a9f0548922

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Gamepad/Gamepad.cpp	Fri May 15 19:57:40 2020 +0000
@@ -0,0 +1,341 @@
+#include "Gamepad.h"
+
+#include "mbed.h"
+
+//////////// constructor/destructor ////////////
+Gamepad::Gamepad()
+    :
+    _led1(new PwmOut(PTA1)),
+    _led2(new PwmOut(PTA2)),
+    _led3(new PwmOut(PTC2)),
+    _led4(new PwmOut(PTC3)),
+    _led5(new PwmOut(PTC4)),
+    _led6(new PwmOut(PTD3)),
+
+    _button_A(new InterruptIn(PTB9)),
+    _button_B(new InterruptIn(PTD0)),
+    _button_X(new InterruptIn(PTC17)),
+    _button_Y(new InterruptIn(PTC12)),
+    _button_L(new InterruptIn(PTB18)),
+    _button_R(new InterruptIn(PTB3)),
+    _button_back(new InterruptIn(PTB19)),
+    _button_start(new InterruptIn(PTC5)),
+    _button_joystick(new InterruptIn(PTC16)),
+
+    _vert(new AnalogIn(PTB10)),
+    _horiz(new AnalogIn(PTB11)),
+
+    _buzzer(new PwmOut(PTC10)),
+    _pot(new AnalogIn(PTB2)),
+
+    _timeout(new Timeout()),
+
+    _event_state(0),
+
+    _x0(0),
+    _y0(0)
+{}
+
+Gamepad::~Gamepad()
+{
+    delete _led1,_led2,_led3,_led4,_led5,_led6;
+    delete _button_A,_button_B,_button_joystick,_vert,_horiz;
+    delete _button_X,_button_Y,_button_back,_button_start;
+    delete _button_L,_button_R, _buzzer, _pot, _timeout;
+}
+
+///////////////// public methods /////////////////
+
+void Gamepad::init()
+{
+    leds_off();
+    init_buttons();
+
+    // read centred values of joystick
+    _x0 = _horiz->read();
+    _y0 = _vert->read();
+
+    // clear all flags
+    _event_state = 0;
+}
+
+void Gamepad::leds_off()
+{
+    leds(0.0);
+}
+
+void Gamepad::leds_on()
+{
+    leds(1.0);
+}
+
+void Gamepad::leds(float val) const
+{
+    if (val < 0.0f) {
+        val = 0.0f;
+    }
+    if (val > 1.0f) {
+        val = 1.0f;
+    }
+
+    // leds are active-low, so subtract from 1.0
+    // 0.0 corresponds to fully-off, 1.0 to fully-on
+    val = 1.0f - val;
+
+    _led1->write(val);
+    _led2->write(val);
+    _led3->write(val);
+    _led4->write(val);
+    _led5->write(val);
+    _led6->write(val);
+}
+
+void Gamepad::led(int n,float val) const
+{
+    // ensure they are within vlaid range
+    if (val < 0.0f) {
+        val = 0.0f;
+    }
+    if (val > 1.0f) {
+        val = 1.0f;
+    }
+    
+    switch (n) {
+        
+        // check for valid LED number and set value
+
+        case 1:
+            _led1->write(1.0f-val);   // active-low so subtract from 1
+            break;
+        case 2:
+            _led2->write(1.0f-val);   // active-low so subtract from 1
+            break;
+        case 3:
+            _led3->write(1.0f-val);   // active-low so subtract from 1
+            break;
+        case 4:
+            _led4->write(1.0f-val);   // active-low so subtract from 1
+            break;
+        case 5:
+            _led5->write(1.0f-val);   // active-low so subtract from 1
+            break;
+        case 6:
+            _led6->write(1.0f-val);   // active-low so subtract from 1
+            break;
+
+    }
+}
+
+float Gamepad::read_pot() const
+{
+    return _pot->read();
+}
+
+void Gamepad::tone(float frequency, float duration)
+{
+    _buzzer->period(1.0f/frequency);
+    _buzzer->write(0.5);  // 50% duty cycle - square wave
+    _timeout->attach(callback(this, &Gamepad::tone_off), duration );
+}
+
+bool Gamepad::check_event(GamepadEvent const id)
+{
+    // Check whether event flag is set
+    if (_event_state[id]) {
+        _event_state.reset(id);  // clear flag
+        return true;
+    } else {
+        return false;
+    }
+}
+
+// this method gets the magnitude of the joystick movement
+float Gamepad::get_mag()
+{
+    Polar p = get_polar();
+    return p.mag;
+}
+
+// this method gets the angle of joystick movement (0 to 360, 0 North)
+float Gamepad::get_angle()
+{
+    Polar p = get_polar();
+    return p.angle;
+}
+
+Direction Gamepad::get_direction()
+{
+    float angle = get_angle();  // 0 to 360, -1 for centred
+
+    Direction d;
+    // partition 360 into segments and check which segment the angle is in
+    if (angle < 0.0f) {
+        d = CENTRE;   // check for -1.0 angle
+    } else if (angle < 22.5f) {  // then keep going in 45 degree increments
+        d = N;
+    } else if (angle < 67.5f) {
+        d = NE;
+    } else if (angle < 112.5f) {
+        d = E;
+    } else if (angle < 157.5f) {
+        d = SE;
+    } else if (angle < 202.5f) {
+        d = S;
+    } else if (angle < 247.5f) {
+        d = SW;
+    } else if (angle < 292.5f) {
+        d = W;
+    } else if (angle < 337.5f) {
+        d = NW;
+    } else {
+        d = N;
+    }
+
+    return d;
+}
+
+///////////////////// private methods ////////////////////////
+
+void Gamepad::tone_off()
+{
+    // called after timeout
+    _buzzer->write(0.0);
+}
+
+void Gamepad::init_buttons()
+{
+    // turn on pull-downs as other side of button is connected to 3V3
+    // button is 0 when not pressed and 1 when pressed
+    _button_A->mode(PullDown);
+    _button_B->mode(PullDown);
+    _button_X->mode(PullDown);
+    _button_Y->mode(PullDown);
+    _button_back->mode(PullDown);
+    _button_start->mode(PullDown);
+    _button_L->mode(PullDown);
+    _button_R->mode(PullDown);
+    _button_joystick->mode(PullDown);
+    // therefore setup rising edge interrupts
+    _button_A->rise(callback(this,&Gamepad::a_isr));
+    _button_B->rise(callback(this,&Gamepad::b_isr));
+    _button_X->rise(callback(this,&Gamepad::x_isr));
+    _button_Y->rise(callback(this,&Gamepad::y_isr));
+    _button_L->rise(callback(this,&Gamepad::l_isr));
+    _button_R->rise(callback(this,&Gamepad::r_isr));
+    _button_start->rise(callback(this,&Gamepad::start_isr));
+    _button_back->rise(callback(this,&Gamepad::back_isr));
+    _button_joystick->rise(callback(this,&Gamepad::joy_isr));
+}
+
+// button interrupts ISRs
+// Each of these simply sets the appropriate event bit in the _event_state
+// variable
+void Gamepad::a_isr()
+{
+    _event_state.set(A_PRESSED);
+}
+void Gamepad::b_isr()
+{
+    _event_state.set(B_PRESSED);
+}
+void Gamepad::x_isr()
+{
+    _event_state.set(X_PRESSED);
+}
+void Gamepad::y_isr()
+{
+    _event_state.set(Y_PRESSED);
+}
+void Gamepad::l_isr()
+{
+    _event_state.set(L_PRESSED);
+}
+void Gamepad::r_isr()
+{
+    _event_state.set(R_PRESSED);
+}
+void Gamepad::back_isr()
+{
+    _event_state.set(BACK_PRESSED);
+}
+void Gamepad::start_isr()
+{
+    _event_state.set(START_PRESSED);
+}
+void Gamepad::joy_isr()
+{
+    _event_state.set(JOY_PRESSED);
+}
+
+// get raw joystick coordinate in range -1 to 1
+// Direction (x,y)
+// North     (0,1)
+// East      (1,0)
+// South     (0,-1)
+// West      (-1,0)
+Vector2D Gamepad::get_coord()
+{
+    // read() returns value in range 0.0 to 1.0 so is scaled and centre value
+    // substracted to get values in the range -1.0 to 1.0
+    float x = 2.0f*( _horiz->read() - _x0 );
+    float y = 2.0f*( _vert->read()  - _y0 );
+
+    // Note: the x value here is inverted to ensure the positive x is to the
+    // right. This is simply due to how the potentiometer on the joystick
+    // I was using was connected up. It could have been corrected in hardware
+    // by swapping the power supply pins. Instead it is done in software so may
+    // need to be changed depending on your wiring setup
+
+    Vector2D coord = {-x,y};
+    return coord;
+}
+
+// This maps the raw x,y coord onto a circular grid.
+// See:  http://mathproofs.blogspot.co.uk/2005/07/mapping-square-to-circle.html
+Vector2D Gamepad::get_mapped_coord()
+{
+    Vector2D coord = get_coord();
+
+    // do the transformation
+    float x = coord.x*sqrt(1.0f-pow(coord.y,2.0f)/2.0f);
+    float y = coord.y*sqrt(1.0f-pow(coord.x,2.0f)/2.0f);
+
+    Vector2D mapped_coord = {x,y};
+    return mapped_coord;
+}
+
+// this function converts the mapped coordinates into polar form
+Polar Gamepad::get_polar()
+{
+    // get the mapped coordinate
+    Vector2D coord = get_mapped_coord();
+
+    // at this point, 0 degrees (i.e. x-axis) will be defined to the East.
+    // We want 0 degrees to correspond to North and increase clockwise to 359
+    // like a compass heading, so we need to swap the axis and invert y
+    float x = coord.y;
+    float y = coord.x;
+
+    float mag = sqrt(x*x+y*y);  // pythagoras
+    float angle = RAD2DEG*atan2(y,x);
+    // angle will be in range -180 to 180, so add 360 to negative angles to
+    // move to 0 to 360 range
+    if (angle < 0.0f) {
+        angle+=360.0f;
+    }
+
+    // the noise on the ADC causes the values of x and y to fluctuate slightly
+    // around the centred values. This causes the random angle values to get
+    // calculated when the joystick is centred and untouched. This is also when
+    // the magnitude is very small, so we can check for a small magnitude and then
+    // set the angle to -1. This will inform us when the angle is invalid and the
+    // joystick is centred
+
+    if (mag < TOL) {
+        mag = 0.0f;
+        angle = -1.0f;
+    }
+
+    Polar p = {mag,angle};
+    return p;
+}
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