Library for ELEC2645 Gamepad PCB. University of Leeds Version 2 January 2020
Dependents: ELEC2645_Ticker_WAV ELEC2645_Project_username ELEC2645_Project_el18vgt ELEC2645_Project_el17oc11 ... more
Gamepad.cpp
- Committer:
- valavanisalex
- Date:
- 2017-03-03
- Revision:
- 13:ef5fc9f58805
- Parent:
- 12:1b0b6355da4f
- Child:
- 14:688bdcbdd3a5
File content as of revision 13:ef5fc9f58805:
#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_back = new InterruptIn(PTB19); _button_start = new InterruptIn(PTC5); _button_L = new InterruptIn(PTB18); _button_R = new InterruptIn(PTB3); _button_joystick = new InterruptIn(PTC16); _vert = new AnalogIn(PTB10); _horiz = new AnalogIn(PTB11); _buzzer = new PwmOut(PTC10); _pot = new AnalogIn(PTB2); _timeout = new Timeout(); } 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::led1(float val) { _led1->write(1.0f-val); // active-low so subtract from 1 } void Gamepad::led2(float val) { _led2->write(1.0f-val); // active-low so subtract from 1 } void Gamepad::led3(float val) { _led3->write(1.0f-val); // active-low so subtract from 1 } void Gamepad::led4(float val) { _led4->write(1.0f-val); // active-low so subtract from 1 } void Gamepad::led5(float val) { _led5->write(1.0f-val); // active-low so subtract from 1 } void Gamepad::led6(float val) { _led6->write(1.0f-val); // active-low so subtract from 1 } 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() { _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(EVENT_A_PRESSED); } void Gamepad::b_isr() { _event_state.set(EVENT_B_PRESSED); } void Gamepad::x_isr() { _event_state.set(EVENT_X_PRESSED); } void Gamepad::y_isr() { _event_state.set(EVENT_Y_PRESSED); } void Gamepad::l_isr() { _event_state.set(EVENT_L_PRESSED); } void Gamepad::r_isr() { _event_state.set(EVENT_R_PRESSED); } void Gamepad::back_isr() { _event_state.set(EVENT_BACK_PRESSED); } void Gamepad::start_isr() { _event_state.set(EVENT_START_PRESSED); } void Gamepad::joy_isr() { _event_state.set(EVENT_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; }