#include <8051.h>

/*
 * Device Layout and Pin Connections
 * ================================
 *
 * LED Layout (from top to bottom):
 * ------------------------------
 * D1  > P0.0
 * D2  > P0.1
 * D3  > P0.2
 * D4  > P0.3
 * D5  > P0.4  (Upper middle LED)
 * D6  > P0.5  (Upper middle LED)
 * D7  > P0.6  (Upper middle LED)
 * D8  > P0.7  (Upper middle LED)
 * D16 > P2.7  (Lower middle LED)
 * D15 > P2.6  (Lower middle LED)
 * D14 > P2.5  (Lower middle LED)
 * D13 > P2.4  (Lower middle LED)
 * D12 > P2.3
 * D11 > P2.2
 * D10 > P2.1
 * D9  > P2.0
 *
 * Switch Connections:
 * ------------------
 * Power Switch > VCC
 * Button      > P3.7
 * Vibration   > P3.2
 *
 * Note: The middle LEDs (D5-D8, D16-D13) are used for the main display pattern
 */

// Define LED ports
#define LEDS_LOW P0    // D1-D8 connected to P0.0-P0.7
#define LEDS_HIGH P2   // D9-D16 connected to P2.0-P2.7

// Button and motion sensor
__sbit __at (0xB7) BUTTON;    // P3.7 Button for changing display
__sbit __at (0xB2) MOTION;    // P3.2 Vibration/motion sensor

// Current mode index
unsigned char currentMode = 0;
#define NUM_MODES 4

// Button debounce variable
__bit lastButtonState = 1;

// IMPORTANT: For active LOW configuration, 0 = LED ON, 1 = LED OFF

// LED mapping:
// P0 (LEDS_LOW): Bits 4-7 control D5-D8 (upper middle)
// P2 (LEDS_HIGH): Bits 4-7 control D13-D16 (lower middle)

// X pattern (active LOW - 0 = ON)
const __code unsigned char bar_pattern_low[] = {
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b10001111,  // D5,D8 ON (X)
    0b01001111,  // D6,D7 ON (X)
    0b01001111,  // D6,D7 ON (X)
    0b10001111,  // D5,D8 ON (X)
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11111111   // All OFF (space)
};

const __code unsigned char bar_pattern_high[] = {
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11110001,  // D16,D13 ON (X)
    0b11110010,  // D15,D14 ON (X)
    0b11110010,  // D15,D14 ON (X)
    0b11110001,  // D16,D13 ON (X)
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11111111,  // All OFF (space)
    0b11111111   // All OFF (space)
};

// Function declarations
void delay_ms(unsigned int ms);
void display_column(unsigned char pattern_low, unsigned char pattern_high);
void check_button(void);
void display_pattern(void);

// Speed control - using user's values that worked well
#define COLUMN_DISPLAY_TIME 3    // Time each column is displayed (milliseconds)
#define COLUMN_SPACE_TIME 1      // Time between columns (milliseconds)

// Main function
void main(void) {
    // Initialize ports - all LEDs OFF
    LEDS_LOW = 0xFF;
    LEDS_HIGH = 0xFF;

    // Main loop
    while(1) {
        // Check for motion
        if (MOTION == 0) {  // Motion detected (active LOW)
            // Display the X pattern
            for(unsigned char i = 0; i < sizeof(bar_pattern_low); i++) {
                display_column(bar_pattern_low[i], bar_pattern_high[i]);
            }
        }
    }
}

// Function to display a single column pattern
void display_column(unsigned char pattern_low, unsigned char pattern_high) {
    // Apply the pattern to both LED groups
    LEDS_LOW = pattern_low;
    LEDS_HIGH = pattern_high;

    // Delay for persistence of vision effect
    delay_ms(COLUMN_DISPLAY_TIME);

    // Turn off all LEDs between columns
    LEDS_LOW = 0xFF;
    LEDS_HIGH = 0xFF;

    // Small delay between columns
    delay_ms(COLUMN_SPACE_TIME);
}

// Function to provide millisecond delay
void delay_ms(unsigned int ms) {
    unsigned int i, j;
    for(i = 0; i < ms; i++) {
        for(j = 0; j < 120; j++);  // Approximately 1ms delay at 12MHz
    }
}