import machine
import utime

RS_PIN = 0  
E_PIN = 1   
D4_PIN = 2  
D5_PIN = 3  
D6_PIN = 4  
D7_PIN = 5  

voltage = 0

BUTTON_INC_PIN = 7 
BUTTON_DEC_PIN = 8  

POTENTIOMETER_PIN = 26

LCD_WIDTH = 16
LCD_LINES = 2

LCD_CLEAR = 0x01
LCD_HOME = 0x02
LCD_CURSOR_ON = 0x0E
LCD_CURSOR_OFF = 0x0C
LCD_CURSOR_BLINK = 0x0D
LCD_CURSOR_BACK = 0x10
LCD_CURSOR_FORWARD = 0x14

def lcd_init():
    lcd_command(0x33)
    lcd_command(0x32)
    lcd_command(0x28)
    lcd_command(0x0C)
    lcd_command(0x06)
    lcd_command(LCD_CLEAR)
    utime.sleep_ms(1)


def lcd_command(cmd):
    lcd_rs.value(0)
    lcd_data_pins(cmd >> 4)
    lcd_enable_pulse()
    lcd_data_pins(cmd & 0x0F)
    lcd_enable_pulse()


def lcd_putc(data):
    lcd_rs.value(1)
    lcd_data_pins(data >> 4)
    lcd_enable_pulse()
    lcd_data_pins(data & 0x0F)
    lcd_enable_pulse()

def lcd_enable_pulse():
    lcd_enable.value(1)
    utime.sleep_us(1)
    lcd_enable.value(0)
    utime.sleep_us(100)


def lcd_data_pins(value):
    lcd_d4.value(value & 0x01)
    lcd_d5.value(value & 0x02)
    lcd_d6.value(value & 0x04)
    lcd_d7.value(value & 0x08)


def read_potentiometer_voltage(v):
    raw_value = potentiometer.read_u16()
    voltage = (raw_value / 65535.0) * 3.3
    voltage_cal = (voltage+v)
    if voltage_cal < 0:
        voltage_cal = 0
    return voltage_cal


lcd_rs = machine.Pin(RS_PIN)
lcd_enable = machine.Pin(E_PIN)
lcd_d4 = machine.Pin(D4_PIN)
lcd_d5 = machine.Pin(D5_PIN)
lcd_d6 = machine.Pin(D6_PIN)
lcd_d7 = machine.Pin(D7_PIN)
potentiometer = machine.ADC(POTENTIOMETER_PIN)

lcd_rs.init(machine.Pin.OUT)
lcd_enable.init(machine.Pin.OUT)
lcd_d4.init(machine.Pin.OUT)
lcd_d5.init(machine.Pin.OUT)
lcd_d6.init(machine.Pin.OUT)
lcd_d7.init(machine.Pin.OUT)
lcd_init()
v = 0.0
while True:

    
    if machine.Pin(BUTTON_INC_PIN, machine.Pin.IN).value() ==1:
        v +=0.1
        print("Button Increase Pressed. Voltage:", voltage)
        machine.Pin(BUTTON_INC_PIN, machine.Pin.OUT).value()
    if machine.Pin(BUTTON_DEC_PIN, machine.Pin.IN).value() == 1:
        v -=0.1
        print("Button Decrease Pressed. Voltage:", voltage)
        machine.Pin(BUTTON_DEC_PIN, machine.Pin.OUT).value()

    
    voltage = read_potentiometer_voltage(v)
    
    lcd_command(LCD_CLEAR)
    lcd_putc(ord("V"))
    lcd_putc(ord("o"))
    lcd_putc(ord("l"))
    lcd_putc(ord("t"))
    lcd_putc(ord("a"))
    lcd_putc(ord("g"))
    lcd_putc(ord("e"))
    lcd_putc(ord(":"))
    lcd_command(LCD_CURSOR_BACK)
    voltage_str = "{:.2f} V".format(voltage)
    for char in voltage_str:
        lcd_putc(ord(char))
        utime.sleep(0.1)