File content as of revision 1:ff57945c704c:

/**
@file main.cpp
@brief program implementation
@author Zang,Junwei
@date May 2015
*/

#include "mbed.h"
#include "N5110.h"
#include "beep.h"

using namespace mbed;
// constructor
/** Create a Beep object connected to the specified PwmOut pin
 *
 * @param pin PwmOut pin to connect to 
 */

BusOut leds(LED1,LED2,LED3,LED4);
BusOut myled(p24);

InterruptIn buttonA(p29);
InterruptIn buttonB(p28);
   
Beep::Beep(PinName pin) : _pwm(pin) {
    _pwm.write(0.0);     // after creating it have to be off
}
 
/** stop the beep instantaneous 
 * usually not used 
 */
void Beep::nobeep() {
    _pwm.write(0.0);
}
 
/** Beep with given frequency and duration.
 *
 * @param frequency - the frequency of the tone in Hz
 * @param time - the duration of the tone in seconds
 */
     
void Beep::beep(float freq, float time) {
 
    _pwm.period(1.0/freq);
    _pwm.write(0.5);            // 50% duty cycle - beep on
    toff.attach(this,&Beep::nobeep, time);   // time to off
}

Beep buzzer(p21);
 
// change this to alter tolerance of joystick direction
#define DIRECTION_TOLERANCE 0.05

// connections for joystick
DigitalIn button(p17);
AnalogIn xPot(p15);
AnalogIn yPot(p16);

// timer to regularly read the joystick
Ticker pollJoystick;

// create enumerated type (0,1,2,3 etc. for direction)
// could be extended for diagonals etc.
enum DirectionName {
    UP,
    DOWN,
    LEFT,
    RIGHT,
    CENTRE,
    UNKNOWN
};

// struct for Joystick
typedef struct JoyStick Joystick;
struct JoyStick {
    float x;    // current x value
    float x0;   // 'centred' x value
    float y;    // current y value
    float y0;   // 'centred' y value
    int button; // button state (assume pull-down used, so 1 = pressed, 0 = unpressed)
    DirectionName direction;  // current direction
};
// create struct variable
Joystick joystick;

// function prototypes
void calibrateJoystick();
void updateJoystick();

// read default positions of the joystick to calibrate later readings
void calibrateJoystick()
{
    button.mode(PullDown);
    // must not move during calibration
    joystick.x0 = xPot;  // initial positions in the range 0.0 to 1.0 (0.5 if centred exactly)
    joystick.y0 = yPot;
}
void updateJoystick()
{
    // read current joystick values relative to calibrated values (in range -0.5 to 0.5, 0.0 is centred)
    joystick.x = xPot - joystick.x0;
    joystick.y = yPot - joystick.y0;
    // read button state
    joystick.button = button;

    // calculate direction depending on x,y values
    // tolerance allows a little lee-way in case joystick not exactly in the stated direction
    if ( fabs(joystick.y) < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
        joystick.direction = CENTRE;
    } else if ( joystick.y > DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
        joystick.direction = DOWN;
    } else if ( joystick.y < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) {
        joystick.direction = UP;
    } else if ( joystick.x > DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) {
        joystick.direction = RIGHT;
    } else if ( joystick.x < DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) {
        joystick.direction = LEFT;
    } else {
        joystick.direction = UNKNOWN;
    }
}

N5110::N5110(PinName pwrPin, PinName scePin, PinName rstPin, PinName dcPin, PinName mosiPin, PinName sclkPin, PinName ledPin)
{
 
    spi = new SPI(mosiPin,NC,sclkPin); // create new SPI instance and initialise
    initSPI();
 
    // set up pins as required
    led = new PwmOut(ledPin);
    pwr = new DigitalOut(pwrPin);
    sce = new DigitalOut(scePin);
    rst = new DigitalOut(rstPin);
    dc = new DigitalOut(dcPin);
 
}
 
// initialise function - powers up and sends the initialisation commands
void N5110::init()
{
    turnOn();     // power up
    wait_ms(10);  // small delay seems to prevent spurious pixels during mbed reset
    reset();      // reset LCD - must be done within 100 ms
 
    // function set - extended
    sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);
    // Don't completely understand these parameters - they seem to work as they are
    // Consult the datasheet if you need to change them
    sendCommand(CMD_VOP_7V38);    // operating voltage - these values are from Chris Yan's Library
    sendCommand(CMD_TC_TEMP_2);   // temperature control
    sendCommand(CMD_BI_MUX_48);   // bias
 
    // function set - basic
    sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE);
    normalMode();  // normal video mode by default
    sendCommand(CMD_DC_NORMAL_MODE);  // black on white
 
    // RAM is undefined at power-up so clear
    clearRAM();
 
}
 
// sets normal video mode (black on white)
void N5110::normalMode()
{
    sendCommand(CMD_DC_NORMAL_MODE);
 
}
 
// sets normal video mode (white on black)
void N5110::inverseMode()
{
    sendCommand(CMD_DC_INVERT_VIDEO);
}
 
// function to power up the LCD and backlight
void N5110::turnOn()
{
    // set brightness of LED - 0.0 to 1.0 - default is 50%
    setBrightness(0.5);
    pwr->write(1);  // apply power
}
 
// function to power down LCD
void N5110::turnOff()
{
    setBrightness(0.0);  // turn backlight off
    clearRAM();   // clear RAM to ensure specified current consumption
    // send command to ensure we are in basic mode
    sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE);
    // clear the display
    sendCommand(CMD_DC_CLEAR_DISPLAY);
    // enter the extended mode and power down
    sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE);
    // small delay and then turn off the power pin
    wait_ms(10);
    pwr->write(0);
 
}
 
// function to change LED backlight brightness
void N5110::setBrightness(float brightness)
{
    // check whether brightness is within range
    if (brightness < 0.0)
        brightness = 0.0;
    if (brightness > 1.0)
        brightness = 1.0;
    // set PWM duty cycle
    led->write(brightness);
}
 
 
// pulse the active low reset line
void N5110::reset()
{
    rst->write(0);  // reset the LCD
    rst->write(1);
}
 
// function to initialise SPI peripheral
void N5110::initSPI()
{
    spi->format(8,1);    // 8 bits, Mode 1 - polarity 0, phase 1 - base value of clock is 0, data captured on falling edge/propagated on rising edge
    spi->frequency(4000000);  // maximum of screen is 4 MHz
}
 
// send a command to the display
void N5110::sendCommand(unsigned char command)
{
    dc->write(0);  // set DC low for command
    sce->write(0); // set CE low to begin frame
    spi->write(command);  // send command
    dc->write(1);  // turn back to data by default
    sce->write(1); // set CE high to end frame (expected for transmission of single byte)
 
}
 
// send data to the display at the current XY address
// dc is set to 1 (i.e. data) after sending a command and so should
// be the default mode.
void N5110::sendData(unsigned char data)
{
    sce->write(0);   // set CE low to begin frame
    spi->write(data);
    sce->write(1);  // set CE high to end frame (expected for transmission of single byte)
}
 
// this function writes 0 to the 504 bytes to clear the RAM
void N5110::clearRAM()
{
    int i;
    sce->write(0);  //set CE low to begin frame
    for(i = 0; i < WIDTH * HEIGHT; i++) { // 48 x 84 bits = 504 bytes
        spi->write(0x00);  // send 0's
    }
    sce->write(1); // set CE high to end frame
 
}
 
// function to set the XY address in RAM for subsequenct data write
void N5110::setXYAddress(int x, int y)
{
    if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) {  // check within range
        sendCommand(0x80 | x);  // send addresses to display with relevant mask
        sendCommand(0x40 | y);
    }
}
 
// These functions are used to set, clear and get the value of pixels in the display
// Pixels are addressed in the range of 0 to 47 (y) and 0 to 83 (x).  The refresh()
// function must be called after set and clear in order to update the display
void N5110::setPixel(int x, int y)
{
    if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) {  // check within range
        // calculate bank and shift 1 to required position in the data byte
        buffer[x][y/8] |= (1 << y%8);
    }
}
 
void N5110::clearPixel(int x, int y)
{
    if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) {  // check within range
        // calculate bank and shift 1 to required position (using bit clear)
        buffer[x][y/8] &= ~(1 << y%8);
    }
}
 
int N5110::getPixel(int x, int y)
{
    if (x>=0 && x<WIDTH && y>=0 && y<HEIGHT) {  // check within range
        // return relevant bank and mask required bit
        return (int) buffer[x][y/8] & (1 << y%8);
        // note this does not necessarily return 1 - a non-zero number represents a pixel
    } else {
        return 0;
    }
}
 
// function to refresh the display
void N5110::refresh()
{
    int i,j;
 
    setXYAddress(0,0);  // important to set address back to 0,0 before refreshing display
    // address auto increments after printing string, so buffer[0][0] will not coincide
    // with top-left pixel after priting string
 
    sce->write(0);  //set CE low to begin frame
 
    for(j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
        for(i = 0; i < WIDTH; i++) {
            spi->write(buffer[i][j]);  // send buffer
        }
    }
    sce->write(1); // set CE high to end frame
 
}
 
// fills the buffer with random bytes.  Can be used to test the display.
// The rand() function isn't seeded so it probably creates the same pattern everytime
void N5110::randomiseBuffer()
{
    int i,j;
    for(j = 0; j < BANKS; j++) {  // be careful to use correct order (j,i) for horizontal addressing
        for(i = 0; i < WIDTH; i++) {
            buffer[i][j] = rand()%256;  // generate random byte
        }
    }
 
}
 
// function to print 5x7 font
void N5110::printChar(char c,int x,int y)
{
    if (y>=0 && y<BANKS) {  // check if printing in range of y banks
 
        for (int i = 0; i < 5 ; i++ ) {
            int pixel_x = x+i;
            if (pixel_x > WIDTH-1)  // ensure pixel isn't outside the buffer size (0 - 83)
                break;
            buffer[pixel_x][y] = font5x7[(c - 32)*5 + i];
            // array is offset by 32 relative to ASCII, each character is 5 pixels wide
        }
 
        refresh();  // this sends the buffer to the display and sets address (cursor) back to 0,0
    }
}
 
// function to print string at specified position
void N5110::printString(const char * str,int x,int y)
{
    if (y>=0 && y<BANKS) {  // check if printing in range of y banks
 
        int n = 0 ; // counter for number of characters in string
        // loop through string and print character
        while(*str) {
 
            // writes the character bitmap data to the buffer, so that
            // text and pixels can be displayed at the same time
            for (int i = 0; i < 5 ; i++ ) {
                int pixel_x = x+i+n*6;
                if (pixel_x > WIDTH-1) // ensure pixel isn't outside the buffer size (0 - 83)
                    break;
                buffer[pixel_x][y] = font5x7[(*str - 32)*5 + i];
            }
 
            str++;  // go to next character in string
 
            n++;    // increment index
 
        }
 
        refresh();  // this sends the buffer to the display and sets address (cursor) back to 0,0
    }
}
 
// function to clear the screen
void N5110::clear()
{
    clearBuffer();  // clear the buffer then call the refresh function
    refresh();
}
 
// function to clear the buffer
void N5110::clearBuffer()
{
    int i,j;
    for (i=0; i<WIDTH; i++) {  // loop through the banks and set the buffer to 0
        for (j=0; j<BANKS; j++) {
            buffer[i][j]=0;
        }
    }
}
 
// function to plot array on display
void N5110::plotArray(float array[])
{
 
    int i;
 
    for (i=0; i<WIDTH; i++) {  // loop through array
        // elements are normalised from 0.0 to 1.0, so multiply
        // by 47 to convert to pixel range, and subtract from 47
        // since top-left is 0,0 in the display geometry
        setPixel(i,47 - int(array[i]*47.0));
    }
 
    refresh();
 
}
 
// function to draw circle
void N5110:: drawCircle(int x0,int y0,int radius,int fill)
{
    // from http://en.wikipedia.org/wiki/Midpoint_circle_algorithm
    int x = radius;
    int y = 0;
    int radiusError = 1-x;
 
    while(x >= y) {
 
        // if transparent, just draw outline
        if (fill == 0) {
            setPixel( x + x0,  y + y0);
            setPixel(-x + x0,  y + y0);
            setPixel( y + x0,  x + y0);
            setPixel(-y + x0,  x + y0);
            setPixel(-y + x0, -x + y0);
            setPixel( y + x0, -x + y0);
            setPixel( x + x0, -y + y0);
            setPixel(-x + x0, -y + y0);
        } else {  // drawing filled circle, so draw lines between points at same y value
 
            int type = (fill==1) ? 1:0;  // black or white fill
 
            drawLine(x+x0,y+y0,-x+x0,y+y0,type);
            drawLine(y+x0,x+y0,-y+x0,x+y0,type);
            drawLine(y+x0,-x+y0,-y+x0,-x+y0,type);
            drawLine(x+x0,-y+y0,-x+x0,-y+y0,type);
        }
 
 
        y++;
        if (radiusError<0) {
            radiusError += 2 * y + 1;
        } else {
            x--;
            radiusError += 2 * (y - x) + 1;
        }
    }
 
}
 
void N5110::drawLine(int x0,int y0,int x1,int y1,int type)
{
    int y_range = y1-y0;  // calc range of y and x
    int x_range = x1-x0;
    int start,stop,step;
 
    // if dotted line, set step to 2, else step is 1
    step = (type==2) ? 2:1;
 
    // make sure we loop over the largest range to get the most pixels on the display
    // for instance, if drawing a vertical line (x_range = 0), we need to loop down the y pixels
    // or else we'll only end up with 1 pixel in the x column
    if ( abs(x_range) > abs(y_range) ) {
 
        // ensure we loop from smallest to largest or else for-loop won't run as expected
        start = x1>x0 ? x0:x1;
        stop =  x1>x0 ? x1:x0;
 
        // loop between x pixels
        for (int x = start; x<= stop ; x+=step) {
            // do linear interpolation
            int y = y0 + (y1-y0)*(x-x0)/(x1-x0);
 
            if (type == 0)   // if 'white' line, turn off pixel
                clearPixel(x,y);
            else
                setPixel(x,y);  // else if 'black' or 'dotted' turn on pixel
        }
    } else {
 
        // ensure we loop from smallest to largest or else for-loop won't run as expected
        start = y1>y0 ? y0:y1;
        stop =  y1>y0 ? y1:y0;
 
        for (int y = start; y<= stop ; y+=step) {
            // do linear interpolation
            int x = x0 + (x1-x0)*(y-y0)/(y1-y0);
 
            if (type == 0)   // if 'white' line, turn off pixel
                clearPixel(x,y);
            else
                setPixel(x,y);  // else if 'black' or 'dotted' turn on pixel
 
        }
    }
 
}
/**
@param 1 - x coordinate
@param 2 - y coordinate
@param 3 - width of the rectangle
@param 4 - height of the rectangle
@param 5 - fill of line
*/
void N5110::drawRect(int x0,int y0,int width,int height,int fill)
{
 
    if (fill == 0) { // transparent, just outline
        drawLine(x0,y0,x0+width,y0,1);  // top
        drawLine(x0,y0+height,x0+width,y0+height,1);  // bottom
        drawLine(x0,y0,x0,y0+height,1);  // left
        drawLine(x0+width,y0,x0+width,y0+height,1);  // right
    } else { // filled rectangle
        int type = (fill==1) ? 1:0;  // black or white fill
        for (int y = y0; y<= y0+height; y++) {  // loop through rows of rectangle
            drawLine(x0,y,x0+width,y,type);  // draw line across screen
        }
    }
 
}

N5110 lcd(p7,p8,p9,p10,p11,p13,p26);  // Initialization of Nokia5110 LCD screen

void flip()  // flip 4 LEDs on mbed and 1 peripheral LED
{
    leds=15;
    myled=1;
    wait(0.5);
    leds=0;
    myled=0;
}
void buttonApressed() // when A button is pressed, turn off the backlight of the screen
{
    lcd.setBrightness(0.0);
}
void buttonBpressed()  // when B button is pressed, turn on the backlight of the screen
{
    lcd.setBrightness(1.0);
}
void changeBrightness()  // a function to include two buttons to make main function simpler and this can also increase the efficiency
{
    buttonA.rise(&buttonApressed);
    buttonB.rise(&buttonBpressed);
}
void gameOver()  // when the car hits the roadblock, clear the screen and display game over and beep/flash to tell the user obviously
{
    lcd.clear();
    lcd.printString("Game Over!",0,0);
    buzzer.beep(5000,0.1);
    wait(0.1);
    buzzer.beep(4000,0.1);
    wait(0.1);
    buzzer.beep(3000,0.1);
    wait(0.1);
    buzzer.beep(2000,0.1);
    wait(0.1);
    buzzer.beep(1000,0.1);
    for(int i = 1;i<4;i++)
    {
        flip();
        wait(0.5);
    }
    lcd.refresh();
}

void welcome()  // when begin the game, display the name and beep to welcome the user
{
    lcd.printString("Fast&Furious-8",0,0);
    lcd.refresh();
    buzzer.beep(1000,0.1);
    wait(0.5);
    buzzer.beep(2000,0.1);
    wait(0.5);
    buzzer.beep(3000,0.1);
    wait(0.5);
    buzzer.beep(30000,0.1);
    wait(0.2);
    buzzer.beep(30000,0.1);
    wait(0.2);
    buzzer.beep(30000,0.1);
    wait(2);
    lcd.clear();
}

void drawBorder()  // 3 lines to distinguish 4 roadways
{
    lcd.drawLine(0,12,83,12,1);
    lcd.drawLine(0,24,83,24,1);
    lcd.drawLine(0,36,83,36,1);
    lcd.refresh();
}

void car_L1()  // when the car is in the first roadway
{
    lcd.clear();
    drawBorder();
    lcd.drawRect(0,4,15,3,1);
    lcd.refresh();
}

void car_L2()  // when the car is in the second roadway
{
    lcd.clear();
    drawBorder();
    lcd.drawRect(0,17,15,3,1);
    lcd.refresh();
}

void car_R1()  // when the car is in the third roadway
{
    lcd.clear();
    drawBorder();
    lcd.drawRect(0,28,15,3,1);
    lcd.refresh();
}

void car_R2()  // when the car is in the fourth roadway
{
    lcd.clear();
    drawBorder();
    lcd.drawRect(0,40,15,3,1);
    lcd.refresh();
}

void moveCar()  // move the car between roadways by using the joystick, and when the car is moving, buzzer will beep
{
    if(joystick.direction == LEFT) // move to roadway L1
    {
        car_L1();
        buzzer.beep(3000,0.1);
        wait(0.2);
        buzzer.beep(3000,0.1);
    }
    if(joystick.direction == UP) // move to roadway L2
    {
        car_L2();
        buzzer.beep(3000,0.1);
        wait(0.2);
        buzzer.beep(3000,0.1);
    }
    if(joystick.direction == DOWN) // move to roadway R1
    {
        car_R1();
        buzzer.beep(3000,0.1);
        wait(0.2);
        buzzer.beep(3000,0.1);
    }
    if(joystick.direction == RIGHT)  // move to roadway R2
    {
        car_R2();
        buzzer.beep(3000,0.1);
        wait(0.2);
        buzzer.beep(3000,0.1);
    }
}

//Basic theory for moving is to clear the original pixels and create new.
void roadBlock_L1(int x)  // creat the roadblock on roadway L1
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,0,1,12,1);
    for(int b=0;b<12;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=0;c<12;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
void roadBlock_L2(int x)  // creat the roadblock on roadway L2
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,12,1,12,1);
    for(int b=13;b<24;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=13;c<24;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
void roadBlock_R1(int x)  // create the roadblock on roadway R1
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,24,1,12,1);
    for(int b=25;b<36;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=25;c<36;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
void roadBlock_R2(int x) // create the roadblock on roadway R2
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,36,1,12,1);
    for(int b=37;b<48;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=37;c<48;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
void roadBlock_L1L2(int x)  // create the roadblock on roadway L1 and L2
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,0,1,24,1);
    for(int b=0;b<24;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=0;c<24;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
void roadBlock_L2R1(int x)  // create the roadblock on roadway L2 and R1
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,12,1,24,1);
    for(int b=12;b<36;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=12;c<36;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
void roadBlock_R1R2(int x)  //create the roadblock on roadway R1 and R2
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,24,1,24,1);
    for(int b=24;b<48;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=24;c<48;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
void roadBlock_L1L2R1(int x)  // create the roadblock on roadway L1, L2 and R1
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,0,1,36,1);
    for(int b=0;b<36;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=0;c<36;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
void roadBlock_L2R1R2(int x)  // create the roadblock on roadway L2, R1 and R2
{
    drawBorder();  // draw the border to avoid if the lines are cleared by unexpected refresh/clear function call.
    lcd.drawRect(x,12,1,36,1);
    for(int b=12;b<48;b++)
    {
        lcd.clearPixel(x+1,b);
    }
    for(int c=12;c<48;c++)
    {
        lcd.clearPixel(0,c);
    }
    moveCar();
    lcd.refresh();
}
// move theory is to clear the original pixels and create new one.
void moveRoadBlock_L1()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_L1(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if(joystick.direction == LEFT and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void moveRoadBlock_L2()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_L2(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if(joystick.direction == UP and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void moveRoadBlock_R1()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_R1(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if(joystick.direction == DOWN and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void moveRoadBlock_R2()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_R2(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if(joystick.direction == RIGHT and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void moveRoadBlock_L1L2()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_L1L2(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if((joystick.direction == LEFT or joystick.direction == UP) and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void moveRoadBlock_L2R1()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_L2R1(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if((joystick.direction == UP or joystick.direction == DOWN) and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void moveRoadBlock_R1R2()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_R1R2(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if((joystick.direction == DOWN or joystick.direction == RIGHT) and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void moveRoadBlock_L1L2R1()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_L1L2R1(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if((joystick.direction == LEFT or joystick.direction == UP or joystick.direction == DOWN) and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void moveRoadBlock_L2R1R2()  // move roadblock down and call game over fuction if hitting occurs
{
    for(int a=82;a>=0;a--)
    {
        roadBlock_L2R1R2(a);
        buzzer.beep(1000,0.1);
        wait(0.2);
        buzzer.beep(1000,0.1);
        wait(0.01);
        if((joystick.direction == UP or joystick.direction == DOWN or joystick.direction == RIGHT) and a<18)
        {
            gameOver();
            a=-1;
            while(1)
            {
                flip();
            }
        }
    }
    wait(0.1);
}
void win()  // when the car passes all of the roadblocks, the user wins the game, this function is used to display "win" interface
{
    lcd.clear();
    lcd.printString("YOU WIN!!!",0,0);
    buzzer.beep(1000,0.2);
    wait(0.1);
    buzzer.beep(2000,0.2);
    wait(0.1);
    buzzer.beep(3000,0.2);
    while(1)
    {
        flip();
    }
}
void start()  // to simplify the main function, this function is added which contains to call all above relative move functions.
{
    moveRoadBlock_L1();
    moveRoadBlock_L1L2R1();
    moveRoadBlock_L2();
    moveRoadBlock_L1L2();
    moveRoadBlock_R1();
    moveRoadBlock_R2();
    moveRoadBlock_L2R1R2();
    moveRoadBlock_R1R2();
    win();
}



int main()
{
    lcd.init();  // fist need to initilize the screen
    
    welcome();  // dislpay welcome interface
    
    calibrateJoystick();  // get centred values of joystick
    pollJoystick.attach(&updateJoystick,1.0/10.0);  // read joystick 10 times per second
    
    changeBrightness();  // used to read from buttons to turn on/off the backlight of the screen
    
    start();
    
    while(1)
    {        
    }
}