import machine
import math
import time
# constants & Pins Declaration
 SEVEN_SEGMENT_START_PIN = 0
ANALOGUE_INPUT_PIN = 26
BUTTON_PIN = 16
diplay_count = 4
measurment_count = 1  
decimal_precision = 3
ADC_range = float((math.pow(2, 16) - 1))
DEBOUNCE_TIME = 50
digit_list_hexdecmial = [0x40, 0x79,0x24,0x30,0x19,0x12,0x02,0x78,0x00,0x10,0x08,0x03,0x46,0x21,0x06,0x0E,0x7F]
# Variables Declaration
display_value = 0
seg_pins = []
display_valu  = 0
button_pin  = None 
analogue_voltage_pin = None
display_select_pins = []
display_timer = None
last_button_press = 0
current_display_index = diplay_count - 1
previous_analogue_voltage = -1
 last_button_pressed = 0

# Function to read the ADC pin and
# to convert the digital value to a voltage level in the 0-3.3V range
# This function updates the value of the display_value global variable
def read_analogue_voltage(pin):  # We can use the pin parameter if needed

    global display_valu , previous_analogue_voltage 
    total_value = sum(pin.read_u16() for _ in range(measurment_count))
    average_val = total_value // measurment_count
    analogue_voltage = round((average_val / ADC_range) * 3.3, decimal_precision)
    if analogue_voltage != previous_analogue_voltage:
        previous_analogue_voltage = analogue_voltage
         new_display_value = int(analogue_voltage * math.pow(10,decimal_precision))
        max_value = math.pow(10, diplay_count) - 1
    if new_display_value > max_value:
            print(f'Warning: {new_display_value} exceeds {max_value}, clipping')
            new_display_value = max_value
    if display_value != new_display_value:
            display_value = new_display_value
            reset_display()
        return analogue_voltage



# Function to disable timer that triggers scanning 7 segment displays
def disable_display_timer():
    global display_timer
    display_timer.deinit()


# Function to enable timer that triggers scanning 7 segment displays
def enable_display_timer():
    global display_timer
    display_timer.init(period=4, mode = machine.Timer.PERIODIC, callback = scan_display)

# Function to handle scanning 7 segment displays
# Display the value stored in the display_value global variable
# on available 7-segment displays
def scan_display(timer_int):
    global  current_display_index, display_value
    digit = int(abs(display_value) // math.pow(10, current_display_index)) % 10
    display_digit(digit, current_display_index, current_display_index == decimal_precision  and decimal_precision != 0)
    current_display_index = (current_display_index - 1) % diplay_count


# Function display the given value on the display with the specified index
# dp_enable specifies if the decimal pooint should be on or off
def display_digit(digit_value, digit_index, dp_enable=False):
    if digit_value < 0 or digit_value > len(digit_list_hexdecmial):
        return

    for pin in display_select_pins:
        pin.value(0)

    mask = digit_list_hexdecmial[digit_value]
    for i in range(7):
        seg_pins[i].value((mask >> i) & 1)

    seg_pins[7].value(not dp_enable)

    if digit_index == -1:
        for pin in display_select_pins:
            pin.value(1)
    elif 0 <= digit_index < diplay_count:
        display_select_pins[digit_index].value(1)

# Function to test avaiable 7-segment displays

def reset_display():
    global current_display_index
    disable_display_timer()
    current_display_index = diplay_count - 1
    display_digit(16, -1)
    time.sleep(0.1)
    enable_display_timer()
def display_value_test():
    for i in range(16):
        display_digit(i, 0)
        time.sleep(0.5)

 

# Function to setup GPIO/ADC pins, timers and interrupts
def setup():
    global seg_pins, display_select_pins, analogue_voltage_pin, button_pin, display_timer
    display_select_pins = [machine.Pin(i, machine.Pin.OUT) for i in range(SEVEN_SEGMENT_START_PIN + 8, SEVEN_SEGMENT_START_PIN + 8 + diplay_count )]
    for pin in display_select_pins:
        pin.value(0)

    seg_pins = [machine.Pin(i, machine.Pin.OUT) for i in range(SEVEN_SEGMENT_START_PIN, SEVEN_SEGMENT_START_PIN + 8)]
    for pin in seg_pins:
        pin.value(1)

    analogue_voltage_pin = machine.ADC(ANALOGUE_INPUT_PIN)
    button_pin = machine.Pin(BUTTON_PIN, machine.Pin.IN, machine.Pin.PULL_UP)

    display_timer = machine.Timer()
    enable_display_timer()

if __name__ == '__main__':
    setup()
    #display_value_test()
    while True:
        if button_pin.value() == 0:
            current_time = time.ticks_ms()
        if current_time - last_button_pressed > DEBOUNCE_TIME:
            last_button_pressed = current_time
            voltage = read_analogue_voltage(analogue_voltage_pin)
        if voltage is not None:
            print(f'Voltage equal {voltage} V')
            time.sleep(0.1)