# Experiment B: Button Debouncing (PULL_UP)
import machine
import utime

button = machine.Pin(5, machine.Pin.IN, machine.Pin.PULL_UP)  # pressed = LOW
led = machine.Pin(16, machine.Pin.OUT)

debounce_delay = 20  # ms
last_stable_state = button.value()
last_raw_state = last_stable_state
last_change_time = utime.ticks_ms()

press_count = 0

print("🔘 Debouncing started (PULL_UP). Pressed = LOW.")

try:
    while True:
        raw = button.value()

        if raw != last_raw_state:
            last_raw_state = raw
            last_change_time = utime.ticks_ms()

        if utime.ticks_diff(utime.ticks_ms(), last_change_time) > debounce_delay:
            if raw != last_stable_state:
                last_stable_state = raw
                if last_stable_state == 0:  # falling to LOW = press
                    led.value(1)
                    press_count += 1
                    print(f"✅ PRESSED! Count: {press_count}")
                else:  # rising to HIGH = release
                    led.value(0)
                    print("🔘 RELEASED.")

        utime.sleep_ms(5)

except KeyboardInterrupt:
    led.value(0)
    print(f"\n🛑 Stopped. Total reliable presses: {press_count}")