from machine import Pin
import time

# Define LCD pin connections
RS = Pin(0, Pin.OUT)
E = Pin(1, Pin.OUT)
D4 = Pin(2, Pin.OUT)
D5 = Pin(3, Pin.OUT)
D6 = Pin(4, Pin.OUT)
D7 = Pin(5, Pin.OUT)

# LCD Commands
LCD_SET_CGRAM_ADDR = 0x40
LCD_SET_DDRAM_ADDR = 0x80

# Initialize LCD
def lcd_send_command(cmd):
    RS.value(0)  # Command mode
    _lcd_send(cmd)

def lcd_send_data(data):
    RS.value(1)  # Data mode
    _lcd_send(data)

def _lcd_send(value):
    # Send high nibble
    D4.value((value >> 4) & 1)
    D5.value((value >> 5) & 1)
    D6.value((value >> 6) & 1)
    D7.value((value >> 7) & 1)
    E.value(1)
    time.sleep_us(1)
    E.value(0)
    
    # Send low nibble
    D4.value(value & 1)
    D5.value((value >> 1) & 1)
    D6.value((value >> 2) & 1)
    D7.value((value >> 3) & 1)
    E.value(1)
    time.sleep_us(1)
    E.value(0)
    time.sleep_ms(2)

def lcd_init():
    time.sleep_ms(15)
    lcd_send_command(0x28)  # Function set: 4-bit mode, 2 lines, 5x8 dots
    lcd_send_command(0x0C)  # Display on, cursor off, blink off
    lcd_send_command(0x06)  # Entry mode: increment cursor, no shift
    lcd_send_command(0x01)  # Clear display
    time.sleep_ms(2)

def lcd_define_char(location, char_map):
    location &= 0x07  # Only 8 locations for custom chars
    lcd_send_command(LCD_SET_CGRAM_ADDR | (location * 8))
    for byte in char_map:
        lcd_send_data(byte)

def lcd_putstr(string):
    for char in string:
        lcd_send_data(ord(char))

def lcd_set_cursor(line, position):
    if line == 0:
        lcd_send_command(LCD_SET_DDRAM_ADDR | position)
    elif line == 1:
        lcd_send_command(LCD_SET_DDRAM_ADDR | (0x40 + position))

# Define the custom character for 'N'
N_char = [
    0b10001,  # 16x8 pixel representation of the letter 'N'
    0b11001,
    0b10101,
    0b10011,
    0b10001,
    0b10001,
    0b10001,
    0b10001
]

# Main program
lcd_init()
lcd_define_char(0, N_char)  # Define custom character at location 0
lcd_set_cursor(0, 0)        # Set cursor to the first line, first position
lcd_putstr(chr(0))          # Display the custom character

while True:
    time.sleep(1)