from machine import Pin, Timer
import time

# Onboard LED
led = Pin("LED", Pin.OUT)

# Shared variables
tick_count = 0
one_second_flag = False

def timer_callback(timer):
    global tick_count
    global one_second_flag

    tick_count += 1

    # 10 × 100 ms = 1 second
    if tick_count % 10 == 0:
        one_second_flag = True


# Create hardware timer
timer = Timer()

# Fire every 100 ms
timer.init(
    freq=10,            # 10 Hz = 100 ms period
    mode=Timer.PERIODIC,
    callback=timer_callback
)

print("Timer Interrupt Demo")
print("Timer interrupt every 100 ms")

last_report = time.ticks_ms()

while True:

    # Process timer events outside interrupt context
    if one_second_flag:
        one_second_flag = False

        led.toggle()

        print("One second elapsed")
        print("Timer ticks:", tick_count)

    # Simulate other work
    if time.ticks_diff(time.ticks_ms(), last_report) > 250:
        last_report = time.ticks_ms()
        print("Main loop doing work...")

    time.sleep_ms(10)