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

seven_segment_pins = [machine.Pin(i,machine.Pin.OUT)for i in range(7)]
dp_pin =machine.Pin(7.machine.Pin.OUT)
seven_segment_digit_pins = [machine.Pin(i,machine.Pin.OUT)for i in range(8,12)]
adc_pin = machine.ADC(28)
button_pin = machine.Pin(16,machine.Pin.IN,machine.Pin.PULL_UP)

button_pressed = False
display_value = 0
seven_segment_timer = machine.Timer(-1)
seven_segments_values =  [    
    0xC0,
    0xF9,
    0xA4,
    0xB0,
    0x99,
    0x92,
    0x82,
    0xF8,
    0x80,
    0x90,
    ]

    debounce_period =200
    last_button_press = time.ticks_ms() 

def read_analogue_voltage(pin):
    global digit_value
    adc_value = adc_pin.read_u16() 
    voltage = adc_value *(3.3 /((2**16)-1))
    print ('voltage',voltage)
    display_value = voltage
def disable_display_timer():
    global seven_segment_timer
    seven_segment_timer.deinit()

def enable_display_timer():
    global seven_segment_timer
    seven_segment_timer.init(mode=Timer.PERIODIC, freq=33, callback = scan_display)

def scan_display(timer_int):

    global display_value
    value = int (display_value *1000)
    for i in range (4):
        digit = value % 10
        dp_enable = i == 3
        display_digit = (digit,i,dp_enable)
        value = value // 10

def display_digit(digit_value, digit_index, dp_enable = False):
    for i in range (4):
        seven_segment_digit_pins[i].value(0)
    for i in range(7):
        seven_segment_pins[i].value((seven_segments_values[digit_value] >> i) & 0x01)

    dp_pin.value(not dp_enable)
    seven_segment_digit_pins[digit_index].value(1)

def display_value_test():
    global display_value
    while True:
        read_analogue_voltage(adc_pin)
        time.sleep(0.5)

def button_handler(pin):
    global button_pressed
    global last_button_press
    if time.ticks_ms() - last_button_press > debounce_period:
        button_pressed = True
        last_button_press = time.ticks_ms()
        read_analogue_voltage(adc_pin)
        print ('button press')

def setup():
    global button_pin
    enable_display_timer()
    button_pin.irq(trigger =Pin.IRQ_FALLING , handler = button_handler)
    
if __name__ == '__main__':
    setup()
    while True :
        timr.sleep(1)