import time   #Import time library for delays (timing control)
import board  #Access Raspberry Pi Pico GPIO pins
import digitalio  #Control digital input/output pins

# -------------------
#SET PARAMETERS
#-----------------

y=60      #Maximum count value (stopwatch resets after 60)
interval = 0.2    # Time delay between counts (speed of counting)

#------------------
#BUTTON INPUTS
#-------------------

sw1=digitallo.DigitalInout (board.GP15)   #Start button (SNI)
swl.direction = digitalio. Direction.INPUT  #Set as INPUT
sw1.pull = digitalio.Pull.UP  #Enable pull-up (pressed = LOW)

sw2 = digitalio.Digitalinout (board.GP16)  #Reset button (SN2)
sw2.direction = digitalio. Direction. INPUT  #Set as INPUT
sw2.pull =  digitalio. Pull.UP  #Enable pull-up (pressed LOW)

#--------------
#SHARED BCD DATA LINES (DO-D3)
#--------------

A = digitalio.DigitalinOut(board.GP2)  #BCD bit #MSB
B = digitalio.DigitalInOut(board.GP3) #BCD bit 1
C = digitalio.DigitalInOut(board.GP4) #BCD bit 2
D = digitalio. DigitalInOut(board.GP5)  #BCD bit 3 #LSB

#Set all BCD pins as OUTPUT
for pin in (A, B, C, DJ:
    pin.direction digitalio.Direction.OUTPUT

bcd pins [A, B, C, D] # Store BCD pins for Beasy looping

#--------------------
#LATCH ENABLE PINS (CD4511 control)
#--------------------

s72 = digitalio DigitalInOut(board. GP0)   # Controls ones display
s72.direction = digitalio. Direction OUTPUT

s71 = digitalio Digitalinout (board.GP1)  # Controls TENS display
s71.direction = digitalio. Direction.OUTPUT
#----------------
#BCD FUNCTIONS
#----------------

def send_bcd(value):
    #Send 4-bit binary value to CD4511 decoder
    for i in range(4):
        bcd_pins[i].value = (value >> 1) & 1 # Extract cach bit

def latch(pin):
    #Send pulse to latch data into 7-segnent display
    pin.value=0 #Enable latch (active low)
    time.sleep(0.001) #Small delay for hardware stability
    pin.value = 1  #Disable latch

def display_number(num):
    #Split number Into tens and ones digits
    tens = num //10
    ones = num % 10

#Send tens digit to left display
send_bcd (tens)
latch (s72)

#Send ones digit to right display
send_bcd(ones)
latch (s71)

def display_off():
    #Turn off all display segments
    for pin in bed_pins:
        pin.value = O #Clear ECD inputs
        
        #Turn OFF both displays
        latch (s72)
        latch(s71)

#-------------------
#HAIN VARIABLES
#-------------------

count = 0  #Current stopwatch value 
running = false  #State of stopwatch (False stopped, True rumming)

#Initial display OFF
display_off()

#-------------------
#MAIN LOOP
#-------------------
while True:
    #Always update display with current count
    display_number(count)
    #------------------
    #START BUTTON (SW1)
    #-------------------
    if not swl.value: #Button pressed (LON signal)
    running = True #Start counting
    print("START STOPWATCH")
    time.sleep(0.3) # Debounce delay

#----------------------
#RESET BUTTON (SW2)
#-----------------------
if not sw2.value：#Button pressed
running False # Stop counting
count = 0 #Reset value to e
print("RESET -> 00")
time.sleep(0.3)# Debounce delay

#-----------------
#COUNTING PROCESS
#-----------------
if running: #Only count when stopwatch is running

time.sleep(interval) #Wait before increasing count
count += 1 #Increase count by 1

#--------------------
MAX VALUE CONDITION
#--------------------

if count > y: #If count exceeds max value
count =0 #Reset back to D
print("MAX reached -> RESET")

#Display formatted output (always 2 digits)

print("Time: {:02d}", format(count))