File content as of revision 4:be4ba8a111ce:

#include "mbed.h"
#include "C12832.h"
#include "MMA7660.h"

AnalogIn potX(p20);
AnalogIn potY(p19);
MMA7660 acc(p28, p27);
C12832 lcd(p5, p7, p6, p8, p11);
Serial term(USBTX, USBRX);

char addr = 0x42;

void pongMasta(void)
{
    DigitalIn play(p14);

    static const int LEFTUP = 0;
    static const int LEFTDOWN = 1;
    static const int RIGHTUP = 2;
    static const int RIGHTDOWN = 3;
    static const int START = 4;
    int badGuy = 12;
    int goodGuy = 12;
    int ballX = 64;
    int ballY = 0;
    int ballState = START;

    I2C masta(p9,p10);
    
    while(1) {
        DigitalIn up(p15);
        DigitalIn down(p12);

        if (up)
            goodGuy--;
        if (down)
            goodGuy++;
            
        if (goodGuy < 0)
            goodGuy = 0;
        if (goodGuy + 5 > lcd.height()-1)
            goodGuy = lcd.height()-6;
        
        if (ballState != START) {
            // Send good guy yo
            masta.start();
            masta.write(addr);
            masta.write((char)goodGuy);
            masta.stop();
        
            // Read bad guy bro
            masta.start();
            masta.write(addr|0x01);
            badGuy = (int)masta.read(addr);
            masta.stop();
        }

        switch(ballState) {
            case LEFTUP:
                ballX--;
                ballY--;
                if (ballX <= 0) {
                    if ((ballY >= badGuy) && (ballY <= badGuy+5))
                        ballState = RIGHTUP;
                    else
                        ballState = START;
                }
                if (ballY <= 0)
                    ballState = LEFTDOWN;
                break;
            case LEFTDOWN:
                ballX--;
                ballY++;
                if (ballX <= 0) {
                    if ((ballY >= badGuy) && (ballY <= badGuy+5))
                        ballState = RIGHTDOWN;
                    else
                        ballState = START;
                }
                if (ballY >= lcd.height()-1)
                    ballState = LEFTUP;
                break;
            case RIGHTUP:
                ballX++;
                ballY--;
                if (ballX >= lcd.width()-1) {
                    if ((ballY >= goodGuy) && (ballY <= goodGuy+5))
                        ballState = LEFTUP;
                    else
                        ballState = START;
                }
                if (ballY <= 0)
                    ballState = RIGHTDOWN;
                break;
            case RIGHTDOWN:
                ballX++;
                ballY++;
                if (ballX >= lcd.width()-1) {
                    if ((ballY >= goodGuy) && (ballY <= goodGuy+5))
                        ballState = LEFTDOWN;
                    else
                        ballState = START;
                }
                if (ballY >= lcd.height()-1)
                    ballState = RIGHTUP;
                break;
            case START:
                ballX = lcd.width()/2;
                ballY = 0;
                goodGuy = 12;
                badGuy = 12;
                //while(!play);
                if (play) {
                    masta.start();
                    term.printf("ack = %d\n\r", masta.write(addr));
                    term.printf("ack = %d\n\r", masta.write(0xFF));
                    masta.stop();
                    ballState = RIGHTDOWN;
                }
                break;
        }

        // Draw stuff
        lcd.cls(); // clear screen
        lcd.circle(ballX, ballY, 2, 1);
        lcd.line(0, badGuy, 0, badGuy+5, 1);
        lcd.line(lcd.width()-1, goodGuy, lcd.width()-1, goodGuy+5, 1);
        lcd.copy_to_lcd();
        wait(0.03);
    }
}

void pongSlave(void)
{
    static const int LEFTUP = 0;
    static const int LEFTDOWN = 1;
    static const int RIGHTUP = 2;
    static const int RIGHTDOWN = 3;
    static const int START = 4;
    int badGuy = 12;
    int goodGuy = 12;
    int ballX = 0;
    int ballY = 64;
    int ballState = START;
    
    I2CSlave slave(p9,p10);
    slave.address(addr);
    
    while(1) {
        if (ballState != START) {
            DigitalIn up(p15);
            DigitalIn down(p12);
            if (up)
                goodGuy--;
            if (down)
                goodGuy++;
            
            if (goodGuy < 0)
                goodGuy = 0;
            if (goodGuy + 5 > lcd.height()-1)
                goodGuy = lcd.height()-6;
        
            char foo = slave.receive();
            char futureBadGuy = slave.read();
            switch (foo) {
                case I2CSlave::WriteAddressed:
                    badGuy = (int)futureBadGuy;
                    break;
                case I2CSlave::ReadAddressed:
                    // Send good guy yo
                    slave.write((char)goodGuy);
                    break;
            }
        }

        switch(ballState) {
            case LEFTUP:
                ballX--;
                ballY--;
                if (ballX <= 0) {
                    if ((ballY >= goodGuy) && (ballY <= goodGuy+5))
                        ballState = RIGHTUP;
                    else
                        ballState = START;
                }
                if (ballY <= 0)
                    ballState = LEFTDOWN;
                break;
            case LEFTDOWN:
                ballX--;
                ballY++;
                if (ballX <= 0) {
                    if ((ballY >= goodGuy) && (ballY <= goodGuy+5))
                        ballState = RIGHTDOWN;
                    else
                        ballState = START;
                }
                if (ballY >= lcd.height()-1)
                    ballState = LEFTUP;
                break;
            case RIGHTUP:
                ballX++;
                ballY--;
                if (ballX >= lcd.width()-1) {
                    if ((ballY >= badGuy) && (ballY <= badGuy+5))
                        ballState = LEFTUP;
                    else
                        ballState = START;
                }
                if (ballY <= 0)
                    ballState = RIGHTDOWN;
                break;
            case RIGHTDOWN:
                ballX++;
                ballY++;
                if (ballX >= lcd.width()-1) {
                    if ((ballY >= badGuy) && (ballY <= badGuy+5))
                        ballState = LEFTDOWN;
                    else
                        ballState = START;
                }
                if (ballY >= lcd.height()-1)
                    ballState = RIGHTUP;
                break;
            case START:
                ballX = lcd.width()/2;
                ballY = 0;
                goodGuy = 12;
                badGuy = 12;
                int bar = slave.receive();
                unsigned char play = slave.read();
                term.printf("bar = %d\tplay = 0x%02X\n\r", bar, play);
                if (bar == I2CSlave::WriteAddressed && play == 0xFF) {
                    ballState = RIGHTDOWN;
                }
                break;
        }

        // Draw stuff
        lcd.cls(); // clear screen
        lcd.circle(ballX, ballY, 2, 1);
        lcd.line(0, goodGuy, 0, goodGuy+5, 1);
        lcd.line(lcd.width()-1, badGuy, lcd.width()-1, badGuy+5, 1);
        lcd.copy_to_lcd();
        wait(0.03);
    }
}

void etchASketch()
{
    int counter = 0;
    acc.setSampleRate(120);
    while(1) {
        int x = (int)((1-potX) * lcd.width());
        int y = (int)((1-potY) * lcd.height());
        lcd.pixel(x, y, 1);
        lcd.copy_to_lcd();
        if (counter > 100) {
            if (acc.x() > 1.3)
                lcd.cls();
            counter = 0;
        }
        counter++;
    }
}

int main()
{
    DigitalIn up(p15);
    DigitalIn down(p12);
    DigitalIn play(p14);
    
    int choice = 0;
    lcd.printf("    Etch-A-Sketch\n");
    lcd.printf("    PongMaster\n");
    lcd.printf("    PongSlave\n");
    while(1) {
        if (up) {
            while(up);
            choice--;
        }
        if (down) {
            while(down); 
            choice++;
        }
        choice = (choice + 3) % 3;
        if (play) {
            while(play);
            lcd.cls();
            switch (choice) {
                case 0:
                    etchASketch();
                    break;
                case 1:
                    pongMasta();
                    break;
                case 2:
                    pongSlave();
                    break;
            }
        }
        for (int i = 0; i < 3; i++) {
            if (choice != i)
                lcd.fillcircle(12,5+i*8,2,0);
        }
        lcd.fillcircle(12,5+choice*8,2,1);
        lcd.copy_to_lcd();
    }
}