Mine Dodger (8051)

/* Made by Ben Duncan (C) */

// Included header files

#include <8051.h>
#include <string.h>
#include <stdio.h>  /* for printf, printf_fast, etc */

// Subroutine decleration

extern void delay_ms(unsigned char ms);
extern void restart(void);
extern char key_char(void);
extern void lcd_putchar(char c);
extern void lcd_command(unsigned char cmd);
extern void lcd_set_xy_raw(unsigned int x_and_y);
extern char a2d(void);
void delay(int s);          // Integer seconds only delay
void display_rules(void);
void display_countdown(char count); // Displays a countdown from 'count' to 0
void generate_player(void);
void generate_enemies(void);

// Memory map locations for TAD board

#define DIL_SWITCH 0x0000       // DIL Switch at address 0000h
#define DAC 0x0600          // DAC at address 0600h
#define LCD_COMMAND_WR 0x0800       // Write LCD Command at address 0800h
#define LCD_STATUS_RD 0x0801        // Read LCD Status at address 0801h
#define LCD_DATA_WR 0x0802      // Write LCD Data at address 0802h
#define LCD_DATA_RD 0x0803      // Read LCD Data at address 0803h
#define COMPARATOR P3_5         // Comparator is set to bit P3.5

// External data locations

volatile xdata at DAC unsigned char dac;
volatile xdata at LCD_COMMAND_WR unsigned char lcd_command_wr;
volatile xdata at LCD_STATUS_RD unsigned char lcd_status_rd;
volatile xdata at LCD_DATA_WR unsigned char lcd_data_wr;
volatile xdata at LCD_DATA_RD unsigned char lcd_data_rd;

// LCD commands

#define LCD_CLEAR_CMD 0x01
#define LCD_HOME_CMD 0x02
#define LCD_ON_CMD 0x0C
#define LCD_SHIFT_CMD 0x10
#define LCD_CONFIG_CMD 0x38

// Macro to merge two parameters into a single 16-bit parameter

#define lcd_set_xy(x, y) (lcd_set_xy_raw((x) + ((y) << 8)))

// LCD screen parameters

#define LCD_HORIZ_SIZE  16
#define LCD_VERT_SIZE   2
#define LCD_BYTES_PER_LINE  (128 / LCD_VERT_SIZE)

// Send serial data to LCD or Serial Port

bit print_to_lcd=0;

// Interrupt declaration

void ex0_isr(void) interrupt 0;
void ex1_isr(void) interrupt 2;

// Set the side of the 'track' the player is on

bit player_side = 0;                        // Defaults to the right side '0'

// Soft-enable/disables interrupts

bit enable_interrupts;

/* Player and characters */

#define PLAYER "X"
#define MINE "*"
#define PLAYER_X 16                     // Sets player to right of screen
#define ENEMY_SPACES 12                     // # spaces enemies can exist in
#define ENEMY_START 0                       // Start position of enemies
#define ENEMY_END_ 11                       // End position of enemies
#define NUM_ENEMY_STR 1                     // Number of enemy strings

/* Enemy sprites */

char enemy_track1[20] = {1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0};  // Sprites of enemies on track 1
char enemy_track2[20] = {1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0};  // Sprites of enemies on track 2

/* Keyboard character codes */

#define BS_KEY 8
#define ESC_KEY 27
#define SPACE_KEY 32
#define DEL_KEY 127

/* Main code section */

void main(){
    /* Initialise devices */
    enable_interrupts = 0;                  // Disallow interrupt functions to change 'player_side' state
    EA=1;                           // Configure interrupt 0 for falling edge on /INT0 (P3.2)
        EX0 = 1;                            // Enable EX0 Interrupt
        EX1 = 1;                            // Enable EX1 Interrupt
    lcd_command(LCD_HOME_CMD);              // Initialise LCD
    lcd_command(LCD_CLEAR_CMD);             // Clear LCD screen
    print_to_lcd=1;                     // Select LCD
    lcd_set_xy(0,0);                    // Select LCD character
    printf_fast("- Mine Dodger! -");            // Display first line of LCD
    lcd_set_xy(0,1);                    // Select LCD character
    printf_fast(" By Ben Duncan  ");            // Display second line of LCD
    delay(3);                       // Wait for 3 seconds
    lcd_command(LCD_CLEAR_CMD);             // Clear LCD screen

    /* Main control loop that exits when 'esc' is pressed on the keyboard */

    do{
        enable_interrupts = 1;              // Allow interrupt functions to change 'player_side' state
        generate_player();              // Print player to screen
        generate_enemies();             // Display enemies on LCD screen
    } while(key_char() != ESC_KEY);             // When 'esc' is pressed escape loop
}

/* Subroutines for Display */

void generate_enemies(void){
    int j,i;
    for(i=0; i<ENEMY_SPACES; i++){
        for(j=0; j<ENEMY_SPACES; j++){
            lcd_set_xy(i, 0);           // Set position of line 1 of enemies
            printf_fast(enemy_track1[j]);
            lcd_set_xy(i, 1);           // Set position of line 2 of enemies
            printf_fast(enemy_track2[j]);
        }
        speed_delay(1);                 // Delay for enemy speed
        i++                     // Move enemies up one place on the screen
        if(i=>ENEMY_SPACES){                // If the next enemy moves past the end position
            i=0;                    // Start at 0 again
        }
    }
}

void generate_player(void){
    lcd_set_xy(PLAYER_X, player_side);          // Place player on right of screen on 'player_side'
    printf_fast(PLAYER);                    // Print player (X)
    delay_ms(10);                       // Wait for LCD to refresh
}

void display_countdown(char count){             // Passes value of countdown
    int n;                          // Counting variable
    lcd_command(LCD_CLEAR_CMD);             // Clear LCD screen
    for(n=count; n>0; n--){                 // Count 5-0
        lcd_set_xy(0,0);                // Select LCD character
        printf_fast("Start in: %d     ", n);        // Display first line of LCD
        delay(1);                   // Wait for 1 second
    }
}

void display_rules(void){
    lcd_command(LCD_CLEAR_CMD);             // Clear LCD screen
    lcd_set_xy(0,0);                    // Select LCD character
    printf_fast("* are the mines ");            // Display first line of LCD
    lcd_set_xy(0,1);                    // Select LCD character
    printf_fast(" & are dangerous");            // Display second line of LCD
    delay(5);                       // Wait for 5 seconds
    lcd_set_xy(0,0);                    // Select LCD character
    printf_fast("X is the vehicle");            // Display first line of LCD
    lcd_set_xy(0,1);                    // Select LCD character
    printf_fast("Avoid the mines!");            // Display second line of LCD
    delay(5);                       // Wait for 5 seconds
}

/* Subroutines for Interrupts */

void ex0_isr(void)  interrupt 0{                // 'Left' button
    if(enable_interrupts==1){               // If enabled
        if(player_side==1){             // If player on right
            player_side = 0;            // Set player to left side
            lcd_set_xy(PLAYER_X,player_side);   // Select location of player
            printf_fast(PLAYER);            // Display player on screen
        }
    }
}

void ex1_isr(void)  interrupt 2{                // 'Right' button
    if(enable_interrupts==1){               // If enabled
        if(player_side==0){             // If player on left
            player_side = 1;            // Set player to right side
            lcd_set_xy(PLAYER_X,player_side);   // Select location of player
            printf_fast(PLAYER);            // Display player on screen
        }
    }
}

/* Subroutines to control and communicate with the LCD */

void putchar(char c)                        // Write character to lcd or serial port
{
    if (print_to_lcd)                   // If print_to_lcd is set then write to lcd
    {
        lcd_putchar(c);
    }
    else                            // Else write to the serial port
    {
    while(!TI);  /* Wait for ready */
    TI=0;
    SBUF = c;
    }
}

char getchar(void)                      // Get character from serial port
{
    char c;
    while(!RI);
    RI =0;
    c = SBUF;
    return c;
}

void restart(void)                      // Soft reset, jumps to address 0000h
{
    _asm
    ljmp    0
    _endasm;
}

char key_char(void)
{
    char c;
    if (RI)
    {
        RI = 0;
        c = SBUF;
    }
    return c;
}

char a2d(void)
{

    unsigned char val=0;

    dac = 0;
    delay_ms(1);
    while (COMPARATOR == 1)
    {
        val = val + 1;
        dac = val;
        delay_ms(1);                    // Allow time for DAC to settle
    }
    return (val);
}


/* This is a simple delay based on a busy loop */
/* with an 11.0592 MHz crystal, the delay lasts */
/* for approximately 1 ms times the number passed */
/* Of course, it will take longer if there are */
/* interrupts occuring... */

void delay_ms(unsigned char ms)
{
    ms;
    _asm
            mov     r0, dpl
00001$:     mov     r1, #250
00002$:     nop
            djnz    r1, 00002$
            djnz    r0, 00001$
            ret
    _endasm;
}

void delay(int s){                      // Wait for 1 second
    int i,j;
    for(j=0; j<4; j++){
        for(i=0; i<s; i++){             // Delays multiple times
            delay_ms(250);              // Quater of a second
        }
    }
}

/* This C-only version is easier to read and understand, but it is
 * not as fast and efficient as the assembly version below.  You
 * should normally use the optimized assembly version, but read
 * this one to understand the code.
 */

volatile xdata at LCD_COMMAND_WR unsigned char lcd_command_wr;
volatile xdata at LCD_STATUS_RD unsigned char lcd_status_rd;
volatile xdata at LCD_DATA_WR unsigned char lcd_data_wr;
volatile xdata at LCD_DATA_RD unsigned char lcd_data_rd;


void lcd_busy(void)
{
    while (lcd_status_rd & 0x80)  ;
}

void lcd_command(unsigned char cmd)
{
    lcd_busy();
    lcd_command_wr = cmd;
}

void lcd_putchar(char c)
{
    lcd_busy();
    if (c=='\n') lcd_command_wr = LCD_CLEAR_CMD;
    else lcd_data_wr = c;
}

void lcd_set_xy_raw(unsigned int x_and_y)
{
    unsigned char x, y;
    if ((x = x_and_y & 255) >= LCD_HORIZ_SIZE) x = LCD_HORIZ_SIZE - 1;
    if ((y = x_and_y >> 8) >= LCD_VERT_SIZE) y = LCD_VERT_SIZE - 1;
    lcd_busy();
    lcd_command_wr = (y * LCD_BYTES_PER_LINE + x) | 0x80;
}

// End