#include <LiquidCrystal.h>

// Transmit rate bps
#define TX_RATE 5

// Pin assignments
#define TX_DATA 3
#define LCD_D4 4
#define LCD_D5 5
#define LCD_D6 6
#define LCD_D7 7
#define LCD_RS 8
#define LCD_EN 9

const char *message = "Hello, world!";

void setup() {
  pinMode(TX_DATA, OUTPUT);

  LiquidCrystal lcd(LCD_RS, LCD_EN, LCD_D4, LCD_D5, LCD_D6, LCD_D7);
  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print(message);

  for (int byte_idx = 0; byte_idx < strlen(message); byte_idx++){
    char tx_byte = message[byte_idx];

    lcd.setCursor(0, 1);
    lcd.print("        ");

    for (int bit_idx = 0; bit_idx < 8; bit_idx++){
      bool tx_bit = tx_byte & (0x80 >> bit_idx);

      digitalWrite(TX_DATA, tx_bit);

      lcd.setCursor(bit_idx, 1);
      lcd.print(tx_bit ? "1" : "0");
      delay(1000/TX_RATE);
    }    
  }
}

void loop() {
  // put your main code here, to run repeatedly:

}