avr_piano/lcd.c

#include <avr/io.h>
#include <util/delay.h>

// Define LCD control pin connections
#define LCD_RS_PIN   PB0
#define LCD_RW_PIN   PB1
#define LCD_E_PIN    PB2
// Define LCD data pin connections
#define LCD_DATA_PORT PORTD
#define LCD_DATA_DDR  DDRD

// Function prototypes
void LCD_init();
void LCD_command(uint8_t cmd);
void LCD_write(uint8_t data);
void LCD_send(char* str);

int main() {
    // Set control pins as outputs
    DDRB |= (1 << LCD_RS_PIN) | (1 << LCD_RW_PIN) | (1 << LCD_E_PIN);
    // Set data pins as outputs
    LCD_DATA_DDR = 0xFF;

    // Initialize LCD
    LCD_init();

    // Display "Hello, World!"
    LCD_send("Hello, World!");

    while (1) {
        // Your main code here
    }

    return 0;
}

// Initialize LCD
void LCD_init() {
    _delay_ms(15);  // Delay for power-on
    LCD_command(0x38);  // Function Set: 8-bit data, 2-line display, 5x8 font
    LCD_command(0x0C);  // Display ON, Cursor OFF, Blink OFF
    LCD_command(0x01);  // Clear display
    _delay_ms(2);  // Delay for Clear Display command
    LCD_command(0x06);  // Entry Mode Set: Increment cursor, No display shift
}

// Send command to LCD
void LCD_command(uint8_t cmd) {
    LCD_RS_PORT &= ~(1 << LCD_RS_PIN);  // Set RS low for command mode
    LCD_RW_PORT &= ~(1 << LCD_RW_PIN);  // Set RW low for write mode
    LCD_DATA_PORT = cmd;  // Send command to data port
    LCD_E_PORT |= (1 << LCD_E_PIN);  // Enable LCD
    _delay_us(1);  // Short delay
    LCD_E_PORT &= ~(1 << LCD_E_PIN);  // Disable LCD
    _delay_us(100);  // Delay for command execution
}

// Write data to LCD
void LCD_write(uint8_t data) {
    LCD_RS_PORT |= (1 << LCD_RS_PIN);  // Set RS high for data mode
    LCD_RW_PORT &= ~(1 << LCD_RW_PIN);  // Set RW low for write mode
    LCD_DATA_PORT = data;  // Send data to data port
    LCD_E_PORT |= (1 << LCD_E_PIN);  // Enable LCD
    _delay_us(1);  // Short delay
    LCD_E_PORT &= ~(1 << LCD_E_PIN);  // Disable LCD
    _delay_us(100);  // Delay for data execution
}

// Send string to LCD
void LCD_send(char* str) {
    while (*str) {
        LCD_write(*str++);
    }
}