# imports
import machine
import math
import time

#######################################
# Pin and constant definitions
#######################################

# MCU pins
SEGMENT_PINS = [machine.Pin(0), machine.Pin(1), machine.Pin(2), machine.Pin(3), machine.Pin(4), machine.Pin(5), machine.Pin(6),machine.Pin(7)]
DIGIT_PINS = [machine.Pin(11), machine.Pin(10), machine.Pin(8), machine.Pin(9)]
BUTTON_PIN = machine.Pin(16, machine.Pin.IN, machine.Pin.PULL_UP)
ADC_PIN = machine.Pin(26)

# Constants
DEBOUNCE_TIME = 200
SCAN_INTERVAL = 10

#######################################
# Global variables
#######################################

display_value = 0

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

def read_analogue_voltage(pin):
    global display_value
    # Read analogue voltage level 16 times and average the readings
    total = 0
    for _ in range(16):
        total += ADC_PIN.read_u16()
    average = total / 16
    # Calculate the corresponding analogue value
    voltage = (average / 65535) * 3.3
    # Update the display_value global variable
    display_value = round(voltage, 3)
    # Debounce the button press
    time.sleep_ms(DEBOUNCE_TIME)

def disable_display_timer():
    # Disable the timer that triggers scanning 7 segment displays
    pass

def enable_display_timer():
    # Enable the timer that triggers scanning 7 segment displays
    pass

def scan_display(timer_int):
    global display_value
    # Read the value stored in the display_value global variable
    value = display_value
    # Display the value on the 7-segment displays
    for i in range(4):
        digit_value = int(value * 1000) % 10
        display_digit(digit_value, i, dp_enable=(i == 1))
        value /= 10

def display_digit(digit_value, digit_index, dp_enable=False):
    # Display the given value on the display with the specified index
    segment_pins = SEGMENT_PINS
    digit_pins = DIGIT_PINS
    # Set the segment pins
    for i in range(7):
        segment_pins[i].value((digit_value >> i) & 1)
    # Set the digit pin
    digit_pins[digit_index].value(1)
    # Set the decimal point pin
    if dp_enable:
        segment_pins[7].value(1)
    else:
        segment_pins[7].value(0)
def display_digit(digit_value, digit_index, dp_enable=False):
    # Display the given value on the display with the specified index
    segment_pins = SEGMENT_PINS
    digit_pins = DIGIT_PINS
    # Set the segment pins
    for i in range(7):
        segment_pins[i].value((digit_value >> i) & 1)
    # Set the digit pin
    digit_pins[digit_index].value(1)
    # Set the decimal point pin
    if dp_enable:
        segment_pins[7].value(1)
    else:
        segment_pins[7].value(0)
def display_value_test():
    # Test available 7-segment displays
    for i in range(4):
        display_digit(i, i)

def setup():
    # Set up GPIO/ADC pins, timers and interrupts
    global BUTTON_PIN, ADC_PIN
    BUTTON_PIN.irq(trigger=machine.Pin.IRQ_FALLING, handler=read_analogue_voltage)
    ADC_PIN = machine.ADC(machine.Pin(26))

if __name__ == '__main__':
    setup()
    display_value_test()
    while True:
        scan_display(None)
        time.sleep_ms(SCAN_INTERVAL)