from machine import ADC, Pin
import time
from utime import sleep
import math

# 7-segment display layout
#       A
#      ---
#  F |  G  | B
#      ---
#  E |     | C
#      ---
#       D

pins = [
    Pin(2, Pin.OUT),  # A
    Pin(3, Pin.OUT),  # B
    Pin(4, Pin.OUT),  # C
    Pin(5, Pin.OUT),  # D
    Pin(6, Pin.OUT),  # E
    Pin(8, Pin.OUT),  # F
    Pin(7, Pin.OUT),  # G
    Pin(0, Pin.OUT)   # DP (not connected)
]

# Common anode 7-segment display digit patterns
digits = [
    [0, 0, 0, 0, 0, 0, 1, 1], # 0
    [1, 0, 0, 1, 1, 1, 1, 1], # 1
    [0, 0, 1, 0, 0, 1, 0, 1], # 2 
    [0, 0, 0, 0, 1, 1, 0, 1], # 3
    [1, 0, 0, 1, 1, 0, 0, 1], # 4
    [0, 1, 0, 0, 1, 0, 0, 1], # 5
    [0, 1, 0, 0, 0, 0, 0, 1], # 6
    [0, 0, 0, 1, 1, 1, 1, 1], # 7
    [0, 0, 0, 0, 0, 0, 0, 1], # 8
    [0, 0, 0, 1, 1, 0, 0, 1], # 9
    [0, 0, 0, 1, 0, 0, 0, 1], # a
    [1, 1, 0, 0, 0, 0, 0, 1], # b
    [0, 1, 1, 0, 0, 0, 1, 1], # C
    [1, 0, 0, 0, 0, 1, 0, 1], # d
    [0, 1, 1, 0, 0, 0, 0, 1], # E
    [0, 1, 1, 1, 0, 0, 0, 1], # F
]

def reset():
    """Turns off all segments on the 7-segment display."""
    for pin in pins:
        pin.value(1)

reset()

switch = Pin(13, Pin.IN)
light = ADC(Pin(26))
iso = 90
gamma = 0.7
rl10 = 50
max_value = 65535
f_stop = 8.0

def calculate_lux(analogValue):
    voltage = analogValue / max_value * 5
    resistance = 2000 * voltage / (1 - voltage / 5)
    return math.pow(rl10 * 1000 * math.pow(10, gamma) / resistance, (1 / gamma))

def calculate_ev_iso_100(lux):
    return math.pow(2, ev) * 2.5
    
def adjust_ev_iso_100(iso):
    return math.log2(100/iso2) * 3

while True:
    for j in range(len(pins) - 1):
        analogValue = light.read_u16()

        pins[j].value(digits[int(str(calculate_lux(analogValue))[0])][j])
    sleep(0.5)