python execution time

[loayn]

Hi,

im new here. im looking into using my pi to do some data acquisition. i have a pulse train i am trying to capture and decode, the shortest pulse width is 14us. i was thinking of using one of the gpios as an interrupt and write some code to capture the time between pulses to ensure i have the entire train. i was thinking of using the time.time() function in python to do this then save all the data to a file and analyse later. im not sure if this is the best way to do what i am thinking. need some help.

[joan]

Why not try and find out? It shouldn't take too long to set up an experiment.

[MarkHaysHarris777]

i have a pulse train i am trying to capture and decode, the shortest pulse width is 14us. ... thinking of using the time.time() function in python ...

That's about 71Khz (something less than a typical 75Khz watch crystal) ; should be totally doable... I agree with Joan, work up an experiment... lay out the maths, and then code it up/ you're not going to hurt anything, and you'll learn a ton...

[Aydan]

i was thinking of using the time.time() function in python to do this

You should use time.clock().
time.time() gives you the current date/time which might get updated via ntp during your program runtime and you'll have a shift in your timing.
time.clock() gives you the cpu run time which is not affected by ntp syncs.
see also

Code: Select all

import time
help(time.time)
help(time.clock)

Regards
Aydan