import machine
import time
#######################################
# Pin and constant definitions
#######################################
SEG_PINS = [0, 1, 2, 3, 4, 5, 6]  # GPIO pins for the seven segments (a, b, c, d, e, f, g)
DP_PIN = 7  # GPIO pin for the decimal point
DIG_PINS = [11, 10, 9, 8]  # GPIO pins for each digit (1, 2, 3, 4)
ANALOG_PIN = 26  # ADC pin for analogue components (potentiometer)
BUTTON_PIN = 16  # Pushbutton pin

#######################################
# Global variables
#######################################
last_button_press_time = 0
debounce_delay = 200  # Debounce delay in milliseconds
max_voltage = 3.3  # Maximum voltage of the ADC input

#######################################
# Segment mapping for digits 0-9
#######################################
segment_map = {
    '0': [1, 1, 1, 1, 1, 1, 0],
    '1': [0, 1, 1, 0, 0, 0, 0],
    '2': [1, 1, 0, 1, 1, 0, 1],
    '3': [1, 1, 1, 1, 0, 0, 1],
    '4': [0, 1, 1, 0, 0, 1, 1],
    '5': [1, 0, 1, 1, 0, 1, 1],
    '6': [1, 0, 1, 1, 1, 1, 1],
    '7': [1, 1, 1, 0, 0, 0, 0],
    '8': [1, 1, 1, 1, 1, 1, 1],
    '9': [1, 1, 1, 1, 0, 1, 1],
    ' ': [0, 0, 0, 0, 0, 0, 0],  # Blank
}

#######################################
# Function definitions
#######################################

# Function to read the ADC pin and
# convert the digital value to a voltage level in the 0-3.3V range
def read_analog_voltage(adc):
    sum_values = 0
    num_samples = 16  # Number of samples to average
    
    for _ in range(num_samples):
        sum_values += adc.read_u16()  # Read ADC value as a 16-bit unsigned integer
    
    average_value = (sum_values / num_samples) * max_voltage / 65535  # Convert ADC reading to voltage
    print("Analog Voltage: {:.2f} V".format(average_value))  # Print voltage in volts
    return average_value

# Function to display a digit on the seven-segment display
def display_digit(digit, position):
    # Set all digit pins to high (disable all digits)
    for pin in DIG_PINS:
        machine.Pin(pin, machine.Pin.OUT).value(1)
    
    # Set the appropriate segments for the digit
    segments = segment_map[digit]
    for i in range(7):
        machine.Pin(SEG_PINS[i], machine.Pin.OUT).value(segments[i])
    
    # Enable the current digit
    machine.Pin(DIG_PINS[position], machine.Pin.OUT).value(0)

# Function to display the voltage on the seven-segment display
def display_voltage(voltage):
    voltage_str = "{:.2f}".format(voltage)  # Format voltage as a string with 2 decimal places
    voltage_str = voltage_str.replace('.', '')  # Remove the decimal point for display
    
    if len(voltage_str) < 4:
        voltage_str = ' ' * (4 - len(voltage_str)) + voltage_str  # Zero-fill to ensure 4 characters

    # Display each digit on the seven-segment display
    for position, digit in enumerate(voltage_str):
        display_digit(digit, position)
        time.sleep(0.005)  # Small delay to ensure each digit is displayed

# Function to setup GPIO/ADC pins and polling loop
def setup():
    global last_button_press_time
    last_button_press_time = 0

    # Initialize ADC pin and other necessary pins
    adc = machine.ADC(machine.Pin(ANALOG_PIN))
    button = machine.Pin(BUTTON_PIN, machine.Pin.IN, machine.Pin.PULL_UP)

    # Initialize seven-segment display pins
    for pin in SEG_PINS + DIG_PINS:
        machine.Pin(pin, machine.Pin.OUT).value(0)

    voltage = 0  # Initialize the voltage variable

    # Main loop for polling button and updating display
    while True:
        # Poll button press
        if button.value() == 0:  # Button pressed (low)
            current_time = time.ticks_ms()
            if current_time - last_button_press_time > debounce_delay:  # Debounce delay
                voltage = read_analog_voltage(adc)
                last_button_press_time = current_time

        # Continuously refresh the display
        display_voltage(voltage)
        time.sleep(0.001)  # Adjust delay as needed to avoid flickering

if __name__ == '__main__':
    setup()