8. utime

MicroPython contains an utime module based upon the time module in the Python standard library.

This module gets measure time intervals and create delays.

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8.1. sleep

The standard microbit library has its own sleep method (in milli-secs).

utime.sleep may be convenient for micro sleeps or sleeps in seconds.

utime.sleep(seconds)

Sleep for the given number of seconds. seconds is an int or float.

utime.sleep_ms(ms)

Delay for given number of milliseconds. milliseconds is a positive int or 0.

utime.sleep_us(us)

Delay for given number of microseconds. microseconds is a positive int or 0.

The code below has a sleep of 2 seconds between scrolling text.

from microbit import *
import utime

while True:
    display.scroll(".")
    utime.sleep(2)

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8.2. ticks

utime.ticks_ms()

Returns an increasing millisecond counter with an arbitrary reference point, that wraps around after some value. This counter is useful for measuring time intervals and implementing delays.

utime.ticks_us()

Returns an increasing microsecond counter with an arbitrary reference point, that wraps around after some value.

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8.3. ticks_add

utime.ticks_add(ticks, delta)

Offset ticks value by a given number, which can be either positive or negative. Given a ticks value, this function allows to calculate a ticks value, delta ticks before or after it.

To find out wrap value use the code below which compares it with usys.maxsize.

Typically it is half of the max integer that the microbit can handle.

from microbit import *
import utime
import usys

# Find out TICKS_MAX used .e.g 1073741823
print(utime.ticks_add(0, -1))
val = utime.ticks_add(0, -1)
print(val)
max_sys = usys.maxsize
print(max_sys/val)

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8.4. ticks_diff

utime.ticks_diff(ticks1, ticks2)

Measure ticks difference between values returned from utime.ticks_ms() or ticks_us() functions, as a signed value which may wrap around.

The argument order is the same as for subtraction operator, ticks_diff(ticks1, ticks2) has the same meaning as ticks1 - ticks2.

8.5. TIMED_OUT

from microbit import *
import utime

display.scroll(pin2.read_digital())
start = utime.ticks_ms()
while pin2.read_digital() == 0:
    if utime.ticks_diff(utime.ticks_ms(), start) > 2000:
        display.scroll("TIMED_OUT")

8.6. Deadline

from microbit import *
import utime

timer = 3000
deadline = utime.ticks_add(utime.ticks_ms(), timer)
while utime.ticks_diff(deadline, utime.ticks_ms()) > 0:
    utime.sleep_ms(200)
display.show(Image.SKULL)

8.7. countdown timer

from microbit import *
import utime

# Set the countdown timer to 10 seconds (10000 milliseconds)
countdown_time = 10000
deadline = utime.ticks_add(utime.ticks_ms(), countdown_time)

while utime.ticks_diff(deadline, utime.ticks_ms()) > 0:
    # Calculate the remaining time
    remaining_time = utime.ticks_diff(deadline, utime.ticks_ms())

    # Convert remaining time to seconds by integer division and display it
    display.show(str(remaining_time // 1000), delay=200))

    # Sleep for a short period to update the display
    utime.sleep_ms(200)

# Display a smiley face when the countdown is complete
display.show(Image.HAPPY)