from machine import Pin
from time import sleep_ms

class LCD:
    def __init__(self, rs, e, d4, d5, d6, d7):
        self.rs = Pin(rs, Pin.OUT)
        self.e = Pin(e, Pin.OUT)
        self.data_pins = [Pin(d4, Pin.OUT), Pin(d5, Pin.OUT), Pin(d6, Pin.OUT), Pin(d7, Pin.OUT)]
        self.init_lcd()

    def pulse_enable(self):
        self.e.on()
        sleep(0.001)
        self.e.off()
        sleep(0.001)

    def send_nibble(self, data):
        for i in range(4):
            self.data_pins[i].value((data >> i) & 1)
        self.pulse_enable()

    def send_byte(self, data, rs_mode):
        self.rs.value(rs_mode)  # 0 = command, 1 = data
        self.send_nibble(data >> 4)  # Send upper nibble
        self.send_nibble(data & 0x0F)  # Send lower nibble

    def command(self, cmd):
        self.send_byte(cmd, 0)

    def write_char(self, char):
        self.send_byte(ord(char), 1)

    def clear(self):
        self.command(0x01)
        sleep(0.002)

    def move_to(self, col, row):
        addr = col + (0x40 if row == 1 else 0x00)
        self.command(0x80 | addr)

    def write_string(self, text):
        for char in text:
            self.write_char(char)

    def init_lcd(self):
        sleep(0.02)  # Wait for power-on
        self.send_nibble(0x03)
        sleep(0.005)
        self.send_nibble(0x03)
        sleep(0.005)
        self.send_nibble(0x03)
        sleep(0.001)
        self.send_nibble(0x02)  # Set to 4-bit mode
        self.command(0x28)  # Function set: 4-bit, 2-line, 5x8 dots
        self.command(0x0C)  # Display on, cursor off, no blinking
        self.command(0x06)  # Entry mode: Increment cursor, no shift
        self.clear()

def scroll_text(lcd, text, row=0, delay=0.3):
    if len(text) <= 16:
        lcd.move_to(0, row)
        lcd.write_string(text)
    else:
        for i in range(len(text) - 16 + 1):
            lcd.move_to(0, row)
            lcd.write_string(text[i:i + 16])
            sleep(delay)
        lcd.move_to(0, row)
        lcd.write_string(" " * 16)  # Clear the row after scrolling

# Main Program
lcd = LCD(rs=4, e=5, d4=18, d5=19, d6=21, d7=22)

while True:
    lcd.clear()
    lcd.write_string("Hello, World!")
    sleep(2)
    lcd.clear()
    scroll_text(lcd, "This is a scrolling text example in MicroPython!", row=0, delay=0.2)