// Define the pin mappings for LCD
#define RS_PIN 9   // Register Select (RS) connected to A9
#define E_PIN 8    // Enable (E) connected to A8

// Helper macros to control pins manually
#define RS_HIGH() (PORTK |= (1 << RS_PIN - 8))  // Set A9 high (RS pin) on PORTK
#define RS_LOW() (PORTK &= ~(1 << RS_PIN - 8))  // Set A9 low (RS pin) on PORTK

#define E_HIGH() (PORTK |= (1 << E_PIN - 8))    // Set A8 high (E pin) on PORTK
#define E_LOW() (PORTK &= ~(1 << E_PIN - 8))    // Set A8 low (E pin) on PORTK

// Function prototypes
void lcdCommand(uint8_t cmd);
void lcdData(uint8_t data);
void lcdInit();
void lcdClear();
void lcdPulseEnable();
void lcdPrint(const char *str);

void setup() {
  // Set the data direction for PORTF (A0-A7) to output
  DDRF = 0xFF;  // Set all A0-A7 (PORTF) as output for LCD data lines
  
  // Set the data direction for PORTK (A8 and A9) to output
  DDRK |= (1 << RS_PIN - 8) | (1 << E_PIN - 8);  // Set A8 and A9 (PORTK) as output for RS and E
  //  1 << 9-8 | 
  // Initialize the LCD
  lcdInit();
  lcdClear();

  // Send some data to display
  lcdCommand(0x80);  // Set cursor to the beginning of the first line (0x80)
  lcdPrint("Hello ");

  lcdCommand(0xC0);  // Set cursor to the second line (0xC0)
  lcdPrint(" How are you");
}

void loop() {
  // Nothing in loop
}

// Function to initialize the LCD in 8-bit mode
void lcdInit() {
  lcdCommand(0x38);  // 8-bit mode, 2-line display, 5x8 font
  lcdCommand(0x0C);  // Display on, cursor off
  lcdCommand(0x06);  // Increment cursor
  lcdCommand(0x01);  // Clear display
  delay(5);          // Wait for display to clear
}

// Function to clear the LCD
void lcdClear() {
  lcdCommand(0x01);  // Clear display command
  delay(5);          // Wait for the command to complete
}

// Function to send a command to the LCD
void lcdCommand(uint8_t cmd) {
  RS_LOW();          // Set RS low for command mode
  PORTF = cmd;       // Put the command on the data bus (PORTF for A0-A7)
  lcdPulseEnable();  // Send the enable pulse
  delay(2);          // Wait for the command to complete
}

// Function to send data to the LCD (characters)
void lcdData(uint8_t data) {
  RS_HIGH();         // Set RS high for data mode
  PORTF = data;      // Put the data on the data bus (PORTF for A0-A7)
  lcdPulseEnable();  // Send the enable pulse
  delay(2);          // Wait for the data to be written
}

// Function to send a pulse on the enable line to latch data/command
void lcdPulseEnable() {
  E_HIGH();          // Set enable high
  delayMicroseconds(1);  // Short delay
  E_LOW();           // Set enable low
  delayMicroseconds(100);  // Wait for LCD to process
}

// Function to print a string on the LCD
void lcdPrint(const char *str) {
  while (*str) {
    lcdData(*str);  // Send each character
    str++;          // Move to the next character
  }
}