from machine import Pin, Timer, ADC, PWM
import time

# -------------------------------
# Pin Setup
# -------------------------------
DIGIT_START = 7      # First digit select pin (digits at pins 7,8,9,10)
DOT_PIN = 11         # Pin for decimal point
SEGMENT_PINS = list(range(7))  # Segment pins A-G (GPIO 0 to 6)

# -------------------------------
# Segment Codes for Numbers 0-9
# -------------------------------
SEGMENT_CODES = [
    0xC0,  # 0
    0xF9,  # 1
    0xA4,  # 2
    0xB0,  # 3
    0x99,  # 4
    0x92,  # 5
    0x82,  # 6
    0xF8,  # 7
    0x80,  # 8
    0x90   # 9
]

# -------------------------------
# Global Variables
# -------------------------------
display_value = 10   # Start at 10

# -------------------------------
# ADC and PWM Setup
# -------------------------------
reading = ADC(26) 
led_pwm = PWM(Pin(27))  
led_pwm.freq(1000)  

# -------------------------------
# Functions
# -------------------------------

def update_display_value(timer): 
    global display_value
    read = reading.read_u16()
    display_value = int((3.3 * read / 65535) * 1000)  # Scale the value to a range of 0-99
    print(f"Display Value: {display_value}")  # Print the current value for debugging

def show_digit(number, position, show_dot=False):
    """Display a single digit on the given position."""
    code = SEGMENT_CODES[number]
    
    # Set segments (A-G) on pins 0-6 according to the code bits.
    for i in range(7):
        segment_state = (code >> i) & 1
        Pin(i, Pin.OUT).value(segment_state)
    
    # Set the decimal point (active LOW)
    Pin(DOT_PIN, Pin.OUT).value(0 if show_dot else 1)
    
    # Enable the selected digit by turning its corresponding pin ON.
    Pin(DIGIT_START + position, Pin.OUT).on()

def scan_display(): 
    """Continuously update the display by scanning all digits."""
    global display_value
    number = display_value
    for i in range(3, -1, -1):
        digit = number % 10  # Get the current digit (least significant digit)
        show_dot = (i == 0)  # Optional: show decimal point on rightmost digit only
        show_digit(digit, i, show_dot)
        time.sleep(0.02)  # Short delay for multiplexing persistence
        Pin(DIGIT_START + i, Pin.OUT).off()  # Disable the digit after displaying
        number //= 10  # Move to the next digit

def setup():
    """Initialize all digit select and dot pins to a known state."""
    for i in range(4):
        Pin(DIGIT_START + i, Pin.OUT).value(0)
    Pin(DOT_PIN, Pin.OUT).value(1)

def control_led_brightness():
    """Control LED brightness based on the potentiometer value."""
    # Read potentiometer value (ADC)
    pot_value = reading.read_u16()
    # Map potentiometer value to the duty cycle (range 0-65535)
    led_pwm.duty_u16(pot_value)  # Use PWM to control brightness (0-65535)

# -------------------------------
# Main Loop
# -------------------------------
def main():
    setup()
    # Create a Timer to update the display value every 1000 milliseconds (1 second)
    Timer().init(period=1000, mode=Timer.PERIODIC, callback=update_display_value)
    
    while True:
        scan_display()  # Update the 7-segment display
        control_led_brightness()  # Adjust LED brightness based on potentiometer value

# Run the program
main()