A correct example of using utime.ticks_add and utime.ticks_diff

[ihornehrutsa]

It seems to me that the official manual is not fully clear, especially for new users.

To all: Could you publish here parts of code from real projects where ticks_add and/or ticks_diff are used?

Thanks.

[Divergentti]

Example:

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def check_uptime(topic, message):
    global mqtt_last_seen
    mqtt_last_seen = utime.ticks_ms()

in main loop:

client.set_callback(check_uptime)
client.subscribe("$SYS/broker/bytes/#")

...

print(utime.ticks_diff(utime.ticks_ms(), mqtt_last_seen))
time.sleep(1.1)

prints:

1108
2210
3312
4413
5515
6616
7718
8820
9921
0 (this when mqtt-message is seen)

Code is now here too: https://github.com/divergentti/kotiauto ... in/main.py

[pythoncoder]

Or at the REPL issue:

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import time
t = time.ticks_ms()

Then wait five seconds and issue

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print(time.ticks_diff(time.ticks_ms(), t))

and you'll see the number of ms you waited (about 5000).

[jimmo]

It seems to me that the official manual is not fully clear, especially for new users.

I agree it's not the most obvious explanation of what's going on. Before I raise a bug, can you explain what you think was specifically unclear or how you'd improve it?

(i.e. is the issue that it's confusing why you need ticks_add and ticks_diff in the first place, or how to actually use it)

Ref: http://docs.micropython.org/en/latest/l ... ticks_diff

[ihornehrutsa]

Thanks, Divergentti
But if your MQTT client lasts ~ 12 days(not rarely for IoT), you will get negative values unexpected for newbies.

Thanks, Peter pythoncoder
But if your code

Code: Select all

import time
t = time.ticks_ms()
time.sleep(5) # or do something
print(time.ticks_diff(time.ticks_ms(), t))

lasts ~ 12 days, you also may get negative values unexpected for newbies.

If time.ticks_us() used

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import time
t = time.ticks_us()
time.sleep(5) # or do something
print(time.ticks_diff(time.ticks_us(), t))

we may get negative values every 18 minutes.

Counter overflow happens.

Only one example from the http://docs.micropython.org/en/latest/l ... ticks_diff

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# This code snippet is not optimized
now = time.ticks_ms()
scheduled_time = task.scheduled_time()
if ticks_diff(scheduled_time, now) > 0:
    print("Too early, let's nap")
    sleep_ms(ticks_diff(scheduled_time, now))
    task.run()
elif ticks_diff(scheduled_time, now) == 0:
    print("Right at time!")
    task.run()
elif ticks_diff(scheduled_time, now) < 0:
    print("Oops, running late, tell task to run faster!")
    task.run(run_faster=true)

is strictly correct, others are not fully.

The question is not closed...
Thanks to all.