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:
- eencae
- Date:
- 2020-01-27
- Revision:
- 22:72357412608d
- Parent:
- 21:da0b4e14c867
- Child:
- 23:8e1a30a69caa
File content as of revision 22:72357412608d:
#include "Gamepad.h" #include "mbed.h" //////////// constructor/destructor //////////// Gamepad::Gamepad() : _led1(new PwmOut(PTA2)), _led2(new PwmOut(PTC2)), _led3(new PwmOut(PTC3)), _led4(new PwmOut(PTA1)), _led5(new PwmOut(PTC10)), _led6(new PwmOut(PTC11)), _button_A(new InterruptIn(PTC7)), _button_B(new InterruptIn(PTC9)), _button_X(new InterruptIn(PTC5)), _button_Y(new InterruptIn(PTC0)), _button_start(new InterruptIn(PTC8)), _vert(new AnalogIn(PTB11)), _horiz(new AnalogIn(PTB10)), _pot1(new AnalogIn(PTB2)), _pot2(new AnalogIn(PTB3)), dac(new AnalogOut(DAC0_OUT)), ticker(new Ticker), timeout(new Timeout), note_timeout(new Timeout), _x0(0), _y0(0) {} ///////////////// public methods ///////////////// void Gamepad::init() { leds_off(); // read centred values of joystick _x0 = _horiz->read(); _y0 = _vert->read(); // Set all buttons to PullUp _button_A->mode(PullUp); _button_B->mode(PullUp); _button_X->mode(PullUp); _button_Y->mode(PullUp); _button_start->mode(PullUp); // Set up interrupts for the fall of buttons _button_A->fall(callback(this,&Gamepad::A_fall_interrupt)); _button_B->fall(callback(this,&Gamepad::B_fall_interrupt)); _button_X->fall(callback(this,&Gamepad::X_fall_interrupt)); _button_Y->fall(callback(this,&Gamepad::Y_fall_interrupt)); _button_start->fall(callback(this,&Gamepad::start_fall_interrupt)); // initalise button flags reset_buttons(); // number of samples _n = 16; _sample_array = new float[_n]; // create sample array for one period between 0.0 and 1.0 for (int i = 0; i < _n ; i++) { _sample_array[i] = 0.5f + 0.5f*sin(i*2*PI/_n); //printf("y[%i] = %f\n",i,_sample_array[i]); } } 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 valid 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_pot1() const { return _pot1->read(); } float Gamepad::read_pot2() const { return _pot2->read(); } // 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; } void Gamepad::reset_buttons() { A_fall = B_fall = X_fall = Y_fall = start_fall = false; } bool Gamepad::A_pressed() { if (A_fall) { A_fall = false; return true; } else { return false; } } bool Gamepad::B_pressed() { if (B_fall) { B_fall = false; return true; } else { return false; } } bool Gamepad::X_pressed() { if (X_fall) { X_fall = false; return true; } else { return false; } } bool Gamepad::Y_pressed() { if (Y_fall) { Y_fall = false; return true; } else { return false; } } bool Gamepad::start_pressed() { if (start_fall) { start_fall = false; return true; } else { return false; } } bool Gamepad::A_held() { // Buttons are configured as PullUp hence the not return !_button_A->read(); } bool Gamepad::B_held() { return !_button_B->read(); } bool Gamepad::X_held() { return !_button_X->read(); } bool Gamepad::Y_held() { return !_button_Y->read(); } bool Gamepad::start_held() { return !_button_start->read(); } ///////////////////// private methods //////////////////////// // 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; } // ISRs for buttons void Gamepad::A_fall_interrupt() { A_fall = true; } void Gamepad::B_fall_interrupt() { B_fall = true; } void Gamepad::X_fall_interrupt() { X_fall = true; } void Gamepad::Y_fall_interrupt() { Y_fall = true; } void Gamepad::start_fall_interrupt() { start_fall = true; } void Gamepad::set_bpm(float bpm) { _bpm = bpm; } void Gamepad::tone(float frequency,float duration) { // calculate time step between samples float dt = 1.0f/(frequency*_n); // start from beginning of LUT _sample = 0; // setup ticker and timeout to stop ticker // the ticker repeats every dt to plat each sample in turn ticker->attach(callback(this, &Gamepad::ticker_isr), dt); // the timeout stops the ticker after the required duration timeout->attach(callback(this, &Gamepad::timeout_isr), duration ); } void Gamepad::play_melody(int length,const int *notes,const int *durations,float bpm,bool repeat) { // copy arguments to member variables _bpm = bpm; _notes = notes; // pointer for array _durations = durations; // pointer for array _melody_length = length; _repeat = repeat; _note = 0; // start from first note play_next_note(); // play the next note in the melody } void Gamepad::write_dac(float val) { if (val < 0.0f) { val = 0.0f; } else if (val > 1.0f) { val = 1.0f; } dac->write(val); } void Gamepad::play_next_note() { // _note is the note index to play // calculate the duration and frequency of the note float duration = 60.0f/(_bpm*_durations[_note]); float frequency = float(_notes[_note]); //printf("[%i] f = %f d = %f\n",_note,frequency,duration); // check if the note is not a space and if not then play the note if (frequency > 0) { tone(frequency,duration); } // the timeout goes to the next note in the melody // double the duration to leave a bit of a gap in between notes to be better // able to distinguish them note_timeout->attach(callback(this, &Gamepad::note_timeout_isr), duration*2.0f ); } // called when the next note needs playing void Gamepad::note_timeout_isr() { _note++; // go onto next note // if in repeat mode then reset the note counter when get to end of melody if (_repeat && _note == _melody_length) { _note=0; } // check if note is within the melody if (_note < _melody_length) { play_next_note(); } } void Gamepad::ticker_isr() { dac->write(_sample_array[_sample%_n]); // use modulo to get index to play _sample++; // increment the sample ready for next time } void Gamepad::timeout_isr() { // stops the ticker to end the note ticker->detach(); }