circuitpython_blink_without_sleep.py

"""
Using time.monotonic() to blink the built-in LED.

Instead of "wait until" think "Is it time yet?"
"""
import time
import digitalio
import board

# How long we want the LED to stay on
BLINK_ON_DURATION = 0.5

# How long we want the LED to stay off
BLINK_OFF_DURATION = 0.25

# When we last changed the LED state
LAST_BLINK_TIME = -1

# Setup the LED pin.
led = digitalio.DigitalInOut(board.D13)
led.direction = digitalio.Direction.OUTPUT

while True:
    # Store the current time to refer to later.
    now = time.monotonic()
    if not led.value:
        # Is it time to turn on?
        if now >= LAST_BLINK_TIME + BLINK_OFF_DURATION:
            led.value = True
            LAST_BLINK_TIME = now
    if led.value:
        # Is it time to turn off?
        if now >= LAST_BLINK_TIME + BLINK_ON_DURATION:
            led.value = False
            LAST_BLINK_TIME = now