SSD1306

/*
 * File:   main.c
 * Author: matej
 *
 * Created on July 26, 2024, 11:45 AM
 */

#include "config_bits.h"

#define _XTAL_FREQ 8000000

void oscillator_config() {
    OSCCONbits.IRCF = 0b111;
    OSCCONbits.SCS = 0b11;
}

void i2c_setup() {
    SSPCON1 = 0b00000000;
    SSPCON1bits.SSPEN = 1;
    SSPCON1bits.SSPM = 0b1000;
    SSPSTAT = 0b00000000;
//    SSPADD = (8000000 / (4 * 100000)) - 1;
    SSPADD = 19;
}

void i2c_start() {
    SEN = 1;
    while(!SSPIF);
    SSPIF = 0;
}

void i2c_stop() {
    PEN = 1;
    while(!SSPIF);
    SSPIF = 0;
}

void i2c_write(unsigned char data) {
    SSPBUF = data;
    while(!SSPIF);
    SSPIF = 0;
}

char i2c_read(unsigned char ack) {
    RCEN = 1;
    while(!SSPIF);
    SSPIF = 0;
    char received = SSPBUF;

    ACKDT = ack;
    ACKEN = 1;
    while(!SSPIF);
    SSPIF = 0;

    return received;
}

void ssd1306_command(unsigned char command) {
    i2c_start();
    i2c_write(0b01111010);
    i2c_write(0b00000000);
    i2c_write(command);
    i2c_stop();
}

void ssd1306_data(unsigned char data) {
    i2c_start();
    i2c_write(0b01111010);
    i2c_write(0b01000000);
    i2c_write(data);
    i2c_stop();
}

void ssd1306_init() {
    ssd1306_command(0b10101110); // Display OFF
    ssd1306_command(0b10101000); // Set MUX
    ssd1306_command(0b00111111); // 1/64 duty
    ssd1306_command(0b11010011); // Set Offset
    ssd1306_command(0b00000000); // No Offset
    ssd1306_command(0b01000000); // Set Display Start Line
    ssd1306_command(0b10100000); // Set Segment Re-map
    ssd1306_command(0b11000000); // Set COM Output Scan Direction
    ssd1306_command(0b11011010); // Set COM Pins Hardware Configuration
    ssd1306_command(0b00010010);
    ssd1306_command(0b10000001); // Set Contrast control
    ssd1306_command(0b01111111); // ?????
    ssd1306_command(0b10100100); // Set Entire Display ON
    ssd1306_command(0b10100110); // Set Normal Display
    ssd1306_command(0b11010101); // Set Oscillator Frequency
    ssd1306_command(0b10000000);
    ssd1306_command(0b10001101); // Enable charge pump regulator
    ssd1306_command(0b00010100);
    ssd1306_command(0b10101111); // Display ON
}


// Function to rotate the bitmap 90 degrees clockwise
void rotateBitmap90DegreesClockwise(const unsigned char *original, unsigned char *rotated) {
    for (int row = 0; row < 8; row++) {
        for (int col = 0; col < 8; col++) {
            int newRow = col;
            int newCol = 7 - row;
            if (original[row] & (1 << col)) {
                rotated[newRow] |= (1 << newCol);
            }
        }
    }
}

void main(void) {
    TRISD0 = 0;
    LATD0 = 1;
    oscillator_config();
    i2c_setup();
    int time = 0;
    while(1) {
        i2c_start();
        i2c_write(0b11010000);
        i2c_write(0b00000000);
        i2c_stop();

        i2c_start();
        i2c_write(0b11010001);
        if(!ACKSTAT) {
            time = i2c_read(1);
        }

        i2c_stop();

        ssd1306_init();
        ssd1306_command(0b00100001); // Set column address
        ssd1306_command(0b00000000); // Start
        ssd1306_command(0b01111111); // End

        ssd1306_command(0b00100010); // Set page address
        ssd1306_command(0b00000000); // Start
        ssd1306_command(0b00000111); // End

        // Write the letter "M" bitmap to the display
//        unsigned char M_bitmap[8] = {
//            0x00,  // Row 0
//            0x66,  // Row 1
//            0x66,  // Row 2
//            0x00,  // Row 3
//            0x00,  // Row 4
//            0x42,  // Row 5
//            0x3C,  // Row 6
//            0x00   // Row 7
//        };

        unsigned char M_bitmap[8] = {
            0b00000000,  // Row 0: 0x00
            0b01100100,  // Row 1: 0x64
            0b01100010,  // Row 2: 0x62
            0b00000010,  // Row 3: 0x02
            0b00000010,  // Row 4: 0x02
            0b01100010,  // Row 5: 0x62
            0b01100100,  // Row 6: 0x64
            0b00000000   // Row 7: 0x00
        };

//         unsigned char M_rotated_bitmap[8] = {0};
//        rotateBitmap90DegreesClockwise(M_bitmap, M_rotated_bitmap);

        // Send the rotated bitmap to the display
        for (int i = 0; i < 8; i++) {
            ssd1306_data(M_bitmap[i]);
        }

        __delay_ms(1000);
    }
    return;
}