# Simple MicroPython code for LCD display in Wokwi
# This code displays information on a 16x2 LCD connected via I2C

from machine import Pin, SoftI2C
from time import sleep

# Simple I2C LCD Driver Class
class SimpleLCD:
    def __init__(self, i2c, addr=0x27):
        self.i2c = i2c
        self.addr = addr
        self.backlight = 0x08  # Backlight on
        self.init_display()
    
    def write_byte(self, data):
        self.i2c.writeto(self.addr, bytearray([data | self.backlight]))
        sleep(0.001)
    
    def write_nibble(self, data):
        self.write_byte(data | 0x04)  # Enable high
        self.write_byte(data & 0xFB)  # Enable low
    
    def write_cmd(self, cmd):
        # Send high nibble
        self.write_nibble(cmd & 0xF0)
        # Send low nibble
        self.write_nibble((cmd << 4) & 0xF0)
    
    def write_data(self, data):
        # Send high nibble with RS=1
        self.write_nibble((data & 0xF0) | 0x01)
        # Send low nibble with RS=1
        self.write_nibble(((data << 4) & 0xF0) | 0x01)
    
    def init_display(self):
        sleep(0.05)
        # Initialize in 4-bit mode
        self.write_nibble(0x30)
        sleep(0.005)
        self.write_nibble(0x30)
        sleep(0.005)
        self.write_nibble(0x30)
        self.write_nibble(0x20)  # 4-bit mode
        
        # Configure display
        self.write_cmd(0x28)  # 4-bit, 2 line, 5x8 font
        self.write_cmd(0x0C)  # Display on, cursor off
        self.write_cmd(0x06)  # Auto increment cursor
        self.clear()
    
    def clear(self):
        self.write_cmd(0x01)
        sleep(0.002)
    
    def cursor(self, col, row):
        positions = [0x80, 0xC0, 0x94, 0xD4]  # Line positions
        self.write_cmd(positions[row] + col)
    
    def print(self, text):
        for char in text:
            self.write_data(ord(char))

# =============================================================================
# MAIN PROGRAM
# =============================================================================

# Initialize I2C (GPIO 21=SDA, GPIO 22=SCL)
i2c = SoftI2C(scl=Pin(22), sda=Pin(21), freq=400000)

# Check if LCD is connected
print("Scanning for I2C devices...")
devices = i2c.scan()
if 0x27 in devices:
    print("LCD found at address 0x27")
else:
    print("No LCD found! Check connections.")

# Initialize LCD
lcd = SimpleLCD(i2c, 0x27)

# Clear screen and display welcome message
lcd.clear()
lcd.cursor(0, 0)  # Column 0, Row 0
lcd.print("Hello Wokwi!")
lcd.cursor(0, 1)  # Column 0, Row 1  
lcd.print("ESP32 LCD Demo")

print("Initial message displayed")
sleep(3)

# Display different information
info_list = [
    ("Temperature:", "25.6 C"),
    ("Humidity:", "68.2 %"),
    ("Time:", "12:34:56"),
    ("Status:", "Online"),
    ("Voltage:", "3.3V"),
    ("Memory:", "Free: 45KB")
]

# Cycle through information
while True:
    for line1, line2 in info_list:
        lcd.clear()
        lcd.cursor(0, 0)
        lcd.print(line1)
        lcd.cursor(0, 1)
        lcd.print(line2)
        print(f"Displayed: {line1} / {line2}")
        sleep(2)
    
    # Display counter
    lcd.clear()
    lcd.cursor(0, 0)
    lcd.print("Counter Demo")
    
    for count in range(10):
        lcd.cursor(0, 1)
        lcd.print(f"Count: {count:02d}")
        print(f"Counter: {count}")
        sleep(1)

# =============================================================================
# WOKWI SETUP INSTRUCTIONS:
# 
# 1. Create ESP32 project in Wokwi
# 2. Add component: LCD 16x2 (I2C)
# 3. Wire connections:
#    - ESP32 GPIO 21 -> LCD SDA
#    - ESP32 GPIO 22 -> LCD SCL
#    - ESP32 3.3V    -> LCD VCC  
#    - ESP32 GND     -> LCD GND
# 4. Set LCD I2C address to 0x27 in diagram.json
# 5. Copy this code to main.py
# 6. Run simulation
# =============================================================================