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

# Segment and digit pin setup
segment_pins = [Pin(i, Pin.OUT) for i in range(7)]
digit_pins = [Pin(i, Pin.OUT) for i in [11, 10, 9, 8]]  # Digit 0–3
dp = Pin(7, Pin.OUT)

# Button input
button_pin = Pin(16, Pin.IN, Pin.PULL_UP)

# ADCs
adc = ADC(Pin(26))  # Slide potentiometer

# Segment codes: 0–9, '-', blank
displayCodes = [
    0x3F,
    0x06,
    0x5B,
    0x4F,
    0x66,
    0x6D,
    0x7D,
    0x07,
    0x7F,
    0x6F,
    0x40,
    0x00  # '-' = 10, blank = 11
]

# Globals
display_value = 162345
display_mode = 0  
current_digit = 0
last_button_time = 0
display_timer = Timer()
digit = [0,1,2,3]
# --- Sensor Reading Functions ---

def read_temperature():
    try:
        val = adc.read_u16()
        voltage = (val / 65535) * 3.3
        #BETA = 3950
        #resistance = 10000 / (3.3 / voltage - 1)
        #temp = 1 / (math.log(resistance / 10000) / BETA + 1 / 298.15) - 273.15
        return voltage
    except:
        return 0

def read_voltage_mv():
    val = adc.read_u16()
    return int((val / 65535) * 3300)

def read_light_percent():
    val = adc.read_u16()
    return int((val / 65535) * 100)

# --- Display Functions ---

def update_display_value():
    global display_value
    if display_mode == 0:
        display_value = read_temperature()
        #display_value = int(temp)  # e.g., 23.6°C → 236
        print(f"Voltage: {display_value:}V")
    elif display_mode == 1:
        voltage_mv = read_voltage_mv()
        display_value = voltage_mv  # e.g., 3.300V → 3300
        print(f"Voltage: {voltage_mv / 1000:.3f}V")
    elif display_mode == 2:
        light = read_light_percent()
        display_value = light  # Percent: 0–100
        print(f"Voltage: {light}V")
    
def display_digit(digit_value, digit_index, dp_enable=False):
    for i in range(7):
        segment_pins[i].value(not ((displayCodes[digit_value] >> i) & 1))
    for i, pin in enumerate(digit_pins):
        pin.value(1 if i == digit_index else 0)
    dp.value(0 if dp_enable else 1)

def clear_display():
    time.sleep(0.01)
    for i, pin in enumerate(digit_pins):
        pin.value(0)
    dp.value(1)

def charToDigit(char):
    if char == '-':
        digit = 10
    elif char.isdigit():
        digit = int(char)
    else:
        digit = 11
    return digit

def scan_display(timer=None):
    global current_digit
    val = abs(display_value)
    val_str = str(val)
    #if len(val_str) < 4:
        #val_str = (" " * (4 - len(val_str))) + val_str
    #elif len(val_str) > 4:
        #val_str = val_str[-4:]
    display_digit (charToDigit(val_str[0]),0,True)
    clear_display()
    display_digit(charToDigit(val_str[2]),1)
    clear_display()
    display_digit(charToDigit(val_str[3]),2)
    clear_display()
    display_digit(charToDigit(val_str[4]),3)
    clear_display()
    
def button_handler(pin):
    global display_mode, last_button_time
    now = time.ticks_ms()
    if time.ticks_diff(now, last_button_time) > 300:
        #display_mode = (display_mode + 1) % 3
        last_button_time = now
        update_display_value()
        print(f"Switched to mode: {display_mode} (0=Temp, 1=Volt, 2=Light)")

# --- Main ---
if __name__ == '__main__':
    button_pin.irq(trigger=Pin.IRQ_FALLING, handler=button_handler)
    #display_timer.init(freq=1000, mode=Timer.PERIODIC, callback=scan_display)

    print("Ready! Press button to switch modes (0=Temp, 1=Volt, 2=Light).")

    try:
        while True:
            scan_display()
    except Exception as e:
        print("Error:", e)