Gamepad.cpp

00001 #include "Gamepad.h"
00002 
00003 #include "mbed.h"
00004 
00005 //////////// constructor/destructor ////////////
00006 Gamepad::Gamepad()
00007     :
00008     _led1(new PwmOut(PTA2)),
00009     _led2(new PwmOut(PTC2)),
00010     _led3(new PwmOut(PTC3)),
00011     _led4(new PwmOut(PTA1)),
00012     _led5(new PwmOut(PTC10)),
00013     _led6(new PwmOut(PTC11)),
00014 
00015     _button_A(new InterruptIn(PTC7)),
00016     _button_B(new InterruptIn(PTC9)),
00017     _button_X(new InterruptIn(PTC5)),
00018     _button_Y(new InterruptIn(PTC0)),
00019     _button_start(new InterruptIn(PTC8)),
00020 
00021     _vert(new AnalogIn(PTB11)),
00022     _horiz(new AnalogIn(PTB10)),
00023 
00024     _pot1(new AnalogIn(PTB2)),
00025     _pot2(new AnalogIn(PTB3)),
00026     
00027     //rca(new PwmOut(PTE25)),
00028     dac(new AnalogOut(DAC0_OUT)),
00029     ticker(new Ticker),
00030     timeout(new Timeout),
00031     note_timeout(new Timeout),
00032 
00033     _x0(0),
00034     _y0(0)
00035 {}
00036 
00037 
00038 ///////////////// public methods /////////////////
00039 
00040 void Gamepad::init()
00041 {
00042     leds_off();
00043 
00044     // read centred values of joystick
00045     _x0 = _horiz->read();
00046     _y0 = _vert->read();
00047 
00048     // Set all buttons to PullUp
00049     _button_A->mode(PullUp);
00050     _button_B->mode(PullUp);
00051     _button_X->mode(PullUp);
00052     _button_Y->mode(PullUp);
00053     _button_start->mode(PullUp);
00054 
00055     // Set up interrupts for the fall of buttons
00056     _button_A->fall(callback(this,&Gamepad::A_fall_interrupt));
00057     _button_B->fall(callback(this,&Gamepad::B_fall_interrupt));
00058     _button_X->fall(callback(this,&Gamepad::X_fall_interrupt));
00059     _button_Y->fall(callback(this,&Gamepad::Y_fall_interrupt));
00060     _button_start->fall(callback(this,&Gamepad::start_fall_interrupt));
00061 
00062     // initalise button flags
00063     reset_buttons();
00064 
00065     // number of samples
00066     _n = 16;
00067     _sample_array = new float[_n];
00068 
00069     // create sample array for one period between 0.0 and 1.0
00070     for (int i = 0; i < _n ; i++) {
00071         _sample_array[i] = 0.5f + 0.5f*sin(i*2*PI/_n);
00072         //printf("y[%i] = %f\n",i,_sample_array[i]);
00073     }
00074 
00075 }
00076 
00077 void Gamepad::leds_off()
00078 {
00079     leds(0.0);
00080 }
00081 
00082 void Gamepad::leds_on()
00083 {
00084     leds(1.0);
00085 }
00086 
00087 void Gamepad::leds(float val) const
00088 {
00089     if (val < 0.0f) {
00090         val = 0.0f;
00091     }
00092     if (val > 1.0f) {
00093         val = 1.0f;
00094     }
00095 
00096     // leds are active-low, so subtract from 1.0
00097     // 0.0 corresponds to fully-off, 1.0 to fully-on
00098     val = 1.0f - val;
00099 
00100     _led1->write(val);
00101     _led2->write(val);
00102     _led3->write(val);
00103     _led4->write(val);
00104     _led5->write(val);
00105     _led6->write(val);
00106 }
00107 
00108 void Gamepad::led(int n,float val) const
00109 {
00110     // ensure they are within valid range
00111     if (val < 0.0f) {
00112         val = 0.0f;
00113     }
00114     if (val > 1.0f) {
00115         val = 1.0f;
00116     }
00117 
00118     switch (n) {
00119 
00120         // check for valid LED number and set value
00121 
00122         case 1:
00123             _led1->write(1.0f-val);   // active-low so subtract from 1
00124             break;
00125         case 2:
00126             _led2->write(1.0f-val);   // active-low so subtract from 1
00127             break;
00128         case 3:
00129             _led3->write(1.0f-val);   // active-low so subtract from 1
00130             break;
00131         case 4:
00132             _led4->write(1.0f-val);   // active-low so subtract from 1
00133             break;
00134         case 5:
00135             _led5->write(1.0f-val);   // active-low so subtract from 1
00136             break;
00137         case 6:
00138             _led6->write(1.0f-val);   // active-low so subtract from 1
00139             break;
00140 
00141     }
00142 }
00143 
00144 float Gamepad::read_pot1() const
00145 {
00146     return _pot1->read();
00147 }
00148 
00149 float Gamepad::read_pot2() const
00150 {
00151     return _pot2->read();
00152 }
00153 
00154 
00155 // this method gets the magnitude of the joystick movement
00156 float Gamepad::get_mag()
00157 {
00158     Polar p = get_polar();
00159     return p.mag;
00160 }
00161 
00162 // this method gets the angle of joystick movement (0 to 360, 0 North)
00163 float Gamepad::get_angle()
00164 {
00165     Polar p = get_polar();
00166     return p.angle;
00167 }
00168 
00169 Direction Gamepad::get_direction()
00170 {
00171     float angle = get_angle();  // 0 to 360, -1 for centred
00172 
00173     Direction d;
00174     // partition 360 into segments and check which segment the angle is in
00175     if (angle < 0.0f) {
00176         d = CENTRE;   // check for -1.0 angle
00177     } else if (angle < 22.5f) {  // then keep going in 45 degree increments
00178         d = N;
00179     } else if (angle < 67.5f) {
00180         d = NE;
00181     } else if (angle < 112.5f) {
00182         d = E;
00183     } else if (angle < 157.5f) {
00184         d = SE;
00185     } else if (angle < 202.5f) {
00186         d = S;
00187     } else if (angle < 247.5f) {
00188         d = SW;
00189     } else if (angle < 292.5f) {
00190         d = W;
00191     } else if (angle < 337.5f) {
00192         d = NW;
00193     } else {
00194         d = N;
00195     }
00196 
00197     return d;
00198 }
00199 
00200 void Gamepad::reset_buttons()
00201 {
00202     A_fall = B_fall = X_fall = Y_fall = start_fall = false;
00203 }
00204 
00205 bool Gamepad::A_pressed()
00206 {
00207     if (A_fall) {
00208         A_fall = false;
00209         return true;
00210     } else {
00211         return false;
00212     }
00213 }
00214 
00215 bool Gamepad::B_pressed()
00216 {
00217     if (B_fall) {
00218         B_fall = false;
00219         return true;
00220     } else {
00221         return false;
00222     }
00223 }
00224 
00225 bool Gamepad::X_pressed()
00226 {
00227     if (X_fall) {
00228         X_fall = false;
00229         return true;
00230     } else {
00231         return false;
00232     }
00233 }
00234 
00235 bool Gamepad::Y_pressed()
00236 {
00237     if (Y_fall) {
00238         Y_fall = false;
00239         return true;
00240     } else {
00241         return false;
00242     }
00243 }
00244 
00245 bool Gamepad::start_pressed()
00246 {
00247     if (start_fall) {
00248         start_fall = false;
00249         return true;
00250     } else {
00251         return false;
00252     }
00253 }
00254 
00255 bool Gamepad::A_held()
00256 {
00257     // Buttons are configured as PullUp hence the not
00258     return !_button_A->read();
00259 }
00260 
00261 bool Gamepad::B_held()
00262 {
00263     return !_button_B->read();
00264 }
00265 
00266 bool Gamepad::X_held()
00267 {
00268     return !_button_X->read();
00269 }
00270 
00271 bool Gamepad::Y_held()
00272 {
00273     return !_button_Y->read();
00274 }
00275 
00276 bool Gamepad::start_held()
00277 {
00278     return !_button_start->read();
00279 }
00280 
00281 ///////////////////// private methods ////////////////////////
00282 
00283 // get raw joystick coordinate in range -1 to 1
00284 // Direction (x,y)
00285 // North     (0,1)
00286 // East      (1,0)
00287 // South     (0,-1)
00288 // West      (-1,0)
00289 Vector2D Gamepad::get_coord()
00290 {
00291     // read() returns value in range 0.0 to 1.0 so is scaled and centre value
00292     // substracted to get values in the range -1.0 to 1.0
00293     float x = 2.0f*( _horiz->read() - _x0 );
00294     float y = 2.0f*( _vert->read()  - _y0 );
00295 
00296     // Note: the y value here is inverted to ensure the positive y is up
00297 
00298     Vector2D coord = {x,-y};
00299     return coord;
00300 }
00301 
00302 // This maps the raw x,y coord onto a circular grid.
00303 // See:  http://mathproofs.blogspot.co.uk/2005/07/mapping-square-to-circle.html
00304 Vector2D Gamepad::get_mapped_coord()
00305 {
00306     Vector2D coord = get_coord();
00307 
00308     // do the transformation
00309     float x = coord.x*sqrt(1.0f-pow(coord.y,2.0f)/2.0f);
00310     float y = coord.y*sqrt(1.0f-pow(coord.x,2.0f)/2.0f);
00311 
00312     Vector2D mapped_coord = {x,y};
00313     return mapped_coord;
00314 }
00315 
00316 // this function converts the mapped coordinates into polar form
00317 Polar Gamepad::get_polar()
00318 {
00319     // get the mapped coordinate
00320     Vector2D coord = get_mapped_coord();
00321 
00322     // at this point, 0 degrees (i.e. x-axis) will be defined to the East.
00323     // We want 0 degrees to correspond to North and increase clockwise to 359
00324     // like a compass heading, so we need to swap the axis and invert y
00325     float x = coord.y;
00326     float y = coord.x;
00327 
00328     float mag = sqrt(x*x+y*y);  // pythagoras
00329     float angle = RAD2DEG*atan2(y,x);
00330     // angle will be in range -180 to 180, so add 360 to negative angles to
00331     // move to 0 to 360 range
00332     if (angle < 0.0f) {
00333         angle+=360.0f;
00334     }
00335 
00336     // the noise on the ADC causes the values of x and y to fluctuate slightly
00337     // around the centred values. This causes the random angle values to get
00338     // calculated when the joystick is centred and untouched. This is also when
00339     // the magnitude is very small, so we can check for a small magnitude and then
00340     // set the angle to -1. This will inform us when the angle is invalid and the
00341     // joystick is centred
00342 
00343     if (mag < TOL) {
00344         mag = 0.0f;
00345         angle = -1.0f;
00346     }
00347 
00348     Polar p = {mag,angle};
00349     return p;
00350 }
00351 
00352 // ISRs for buttons
00353 void Gamepad::A_fall_interrupt()
00354 {
00355     A_fall = true;
00356 }
00357 void Gamepad::B_fall_interrupt()
00358 {
00359     B_fall = true;
00360 }
00361 void Gamepad::X_fall_interrupt()
00362 {
00363     X_fall = true;
00364 }
00365 void Gamepad::Y_fall_interrupt()
00366 {
00367     Y_fall = true;
00368 }
00369 void Gamepad::start_fall_interrupt()
00370 {
00371     start_fall = true;
00372 }
00373 
00374 
00375 void Gamepad::set_bpm(float bpm)
00376 {
00377     _bpm = bpm;
00378 }
00379 
00380 void Gamepad::tone(float frequency,float duration)
00381 {
00382     // calculate time step between samples
00383     float dt = 1.0f/(frequency*_n);
00384     // start from beginning of LUT
00385     _sample = 0;
00386 
00387     // setup ticker and timeout to stop ticker
00388 
00389     // the ticker repeats every dt to plat each sample in turn
00390     ticker->attach(callback(this, &Gamepad::ticker_isr), dt);
00391     // the timeout stops the ticker after the required duration
00392     timeout->attach(callback(this, &Gamepad::timeout_isr), duration );
00393 }
00394 
00395 void Gamepad::play_melody(int length,const int *notes,const int *durations,float bpm,bool repeat)
00396 {
00397     // copy arguments to member variables
00398     _bpm = bpm;
00399     _notes = notes;  // pointer for array
00400     _durations = durations;  // pointer for array
00401     _melody_length = length;
00402     _repeat = repeat;
00403 
00404     _note = 0;  // start from first note
00405 
00406     play_next_note(); // play the next note in the melody
00407 }
00408 
00409 void Gamepad::write_dac(float val)
00410 {
00411     if (val < 0.0f) {
00412         val = 0.0f;
00413     } else if (val > 1.0f) {
00414         val = 1.0f;
00415     }
00416     dac->write(val);
00417 }
00418 
00419 //writes DAC value in uint format
00420 void Gamepad::write_u16(unsigned short val)
00421 {
00422     if (val > 65535) {
00423         #ifdef CSV //used for error detection in CSV file
00424         printf("/nERROR OUTPUT VALUE= %u",val);
00425         #endif
00426         val = 65535;
00427     }
00428     dac->write_u16(val);
00429 }
00430 
00431 void Gamepad::play_next_note()
00432 {
00433     // _note is the note index to play
00434 
00435     // calculate the duration and frequency of the note
00436     float duration = 60.0f/(_bpm*_durations[_note]);
00437     float frequency = float(_notes[_note]);
00438     //printf("[%i] f = %f d = %f\n",_note,frequency,duration);
00439 
00440     // check if the note is not a space and if not then play the note
00441     if (frequency > 0) {
00442         tone(frequency,duration);
00443     }
00444 
00445     // the timeout goes to the next note in the melody
00446     // double the duration to leave a bit of a gap in between notes to be better
00447     // able to distinguish them
00448     note_timeout->attach(callback(this, &Gamepad::note_timeout_isr), duration*2.0f );
00449 }
00450 
00451 // called when the next note needs playing
00452 void Gamepad::note_timeout_isr()
00453 {
00454     _note++; // go onto next note
00455 
00456     // if in repeat mode then reset the note counter when get to end of melody
00457     if (_repeat && _note == _melody_length) {
00458         _note=0;
00459     }
00460 
00461     // check if note is within the melody
00462     if (_note < _melody_length) {
00463         play_next_note();
00464     }
00465 }
00466 
00467 void Gamepad::ticker_isr()
00468 {
00469     dac->write(_sample_array[_sample%_n]);  // use modulo to get index to play
00470     _sample++;  // increment the sample ready for next time
00471 }
00472 
00473 void Gamepad::timeout_isr()
00474 {
00475     // stops the ticker to end the note
00476     ticker->detach();
00477 }