File content as of revision 6:050104c0dc75:

// A solution to OCE360 Homework #4.
// Objective: Use object oriented programming to create a system that displays
// multiple balls bouncing around the LCD screen.
// Stephen Licht, 11/7/2017

#include "mbed.h"
#include "MMA8452Q.h"           //acceleromater library
#include "uLCD_4DGL.h"          //LCD library
#include "bouncing_ball.h"      //new ball phyics library

#define UPDATE_TIME_S 0.02
#define START_X_1 10
#define START_Y_1 10
#define START_X_2 20
#define START_Y_2 20
#define RADIUS_1 6
#define RADIUS_2 3

#define DEBUG_MODE 0

#define LCD_UPDATE .091         //11 Hz
#define DRAW_UPDATE 0.075

//Initialize Serial communication
Serial pc(USBTX, USBRX);

//Led Initialization
DigitalOut led1(LED1); //update leds
DigitalOut led2(LED2);

//Button Initialization
DigitalIn button(p13);

//Function prototype for color selection function:
int get_LCD_color(int color_integer);

// Graphic LCD - TX, RX, and RES pins
uLCD_4DGL uLCD(p9,p10,p11);     //initialize a driver object for an LCD connected on pins 9-11

// Accelerometer - SDA, SCL, and I2C address
MMA8452Q accel(p28, p27, 0x1D);  //initialize a driver object for an accelerometer connected on pins 27-28.

physics_ball ball1;  //initialize two balls for bouncing
physics_ball ball2;  //the default states from the library will be used initially

//Ticker for logging
Ticker logger1; //ball 1 ticker (position log)
Ticker logger2; //ball 2 ticker (position log)

void pos_log1(){
    pc.printf("Ball 1 (x): %i     Ball 1 (y): %i     \n\r",ball1.posx,ball1.posy);
    //prints ball 1 position to terminal
    }
    
void pos_log2(){
    pc.printf("Ball 2 (x): %i     Ball 2 (y): %i     \n\r",ball2.posx,ball2.posy);
    //prints ball 2 position to terminal
    }

//Ticker for update
Ticker update1; //ball 1 ticker for update position
Ticker update2; //ball 2 ticker for update position

void ball1up(){
    ball1.update(UPDATE_TIME_S,accel);  //updates position
    led1 = !led1;                       //changes led state every update
    }

void ball2up(){
    ball2.update(UPDATE_TIME_S,accel);  //updates position
    led2 = !led2;                       //changes led state every update
    }

//Ticker for display
Ticker displayup;   //ticker for displaying ball on lcd

void display(){
    // Draw circles in the x and y positions stored by the ball objects:
    uLCD.filled_circle(ball1.posx, ball1.posy, ball1.radius, get_LCD_color(ball1.color));
    uLCD.filled_circle(ball2.posx, ball2.posy, ball2.radius, get_LCD_color(ball2.color));

    // Wait before erasing old circles:
    wait(DRAW_UPDATE);         // In seconds

    // Erase old circles by writing over there locations using the screen color:
    uLCD.filled_circle(ball1.posx, ball1.posy, ball1.radius, BLACK);
    uLCD.filled_circle(ball2.posx, ball2.posy, ball2.radius, BLACK);
    }

int main(){
    /*
    logger1.attach(&pos_log1, LOG_UPDATE);
    logger2.attach(&pos_log2, LOG_UPDATE);
    */
    // Initialize uLCD
    uLCD.baudrate(115200);
    uLCD.background_color(BLACK);
    uLCD.cls();

    // Initialize accelerometer
    accel.init();

    //Initialize balls:
    ball1.set_state(START_X_1,START_Y_1,0,0); //speeds are set to zero
    ball1.set_state(START_X_2,START_Y_2,0,0);

    //Set ball radius and color:
    ball1.set_param(RADIUS_1,0); //color is unimportant
    ball2.set_param(RADIUS_2,1); //just making sure the colors are different

    update1.attach(&ball1up,UPDATE_TIME_S); //ticker force position update ball 1
    update2.attach(&ball2up,UPDATE_TIME_S); //ticker force position update ball 2
    
    displayup.attach(&display,LCD_UPDATE);   //ticker force lcd update
    
    while (1) {  //execute 'forever'
        
        if (DEBUG_MODE) {
            //If compiled with DEBUG_MODE flag raised, print values to screen.
            uLCD.locate(0,4);
            uLCD.printf("X: %d.1\nY: %.1d",ball1.posx,ball1.posy);

            uLCD.locate(0,6);
            uLCD.printf("VX: %f.1\nVY: %.1f",ball1.speedx,ball1.speedy);

            uLCD.locate(0,10);
            uLCD.printf("AX: %f.1\nAY: %.1f\nAZ: %0.1f",accel.readX(),accel.readY(),accel.readZ());
        }
    }
}

//Interpret LCD colors.
int get_LCD_color(int color_integer)
{
    switch (color_integer) {
        case 0:
            return(RED);
        case 1:
            return(BLUE);
        case 2:
            return(GREEN);
        default:
            return(WHITE);
    }
}