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waiting for GPIO button press eating resources
Posted: Thu Feb 14, 2019 9:28 pm
by uilfut
Hey guys
Running my script to wait for a GPIO button press (which prints some stats on al oled screen) takes my processor from 2% to 25%.
As soon as I press the button it goes down to 2% from 25% for 10 seconds while stats are displayed).
I have a simple while loop:
Code: Select all
while True:
if GPIO.input(15):
display_on_oled()
Can I do anything to make it use less resources?
Many thanks
Will
Re: waiting for GPIO button press eating resources
Posted: Thu Feb 14, 2019 9:34 pm
by B.Goode
I have no idea if it would use less CPU, but the gpiozero python library module has a Button class that implements a wait_for_press() method. (A timeout can be specified.)
Worth a comparison?
Re: waiting for GPIO button press eating resources
Posted: Thu Feb 14, 2019 9:49 pm
by mattmiller
Can I do anything to make it use less resources?
stick a small time.sleep() in the loop
Your loop is running around in a very small circle very fast wearing itself out
Re: waiting for GPIO button press eating resources
Posted: Thu Feb 14, 2019 10:05 pm
by uilfut
(Thanks both for suggestions!)
mattmiller wrote: ↑Thu Feb 14, 2019 9:49 pm
Can I do anything to make it use less resources?
stick a small time.sleep() in the loop
Yes I thought of this - but if I had, say a time.sleep(2), would I have to hold the button down for up to 2 seconds before it registered?
Sorry if this is basic misunderstanding...
Re: waiting for GPIO button press eating resources
Posted: Thu Feb 14, 2019 10:13 pm
by uilfut
uilfut wrote: ↑Thu Feb 14, 2019 10:05 pm
(Thanks both for suggestions!)
mattmiller wrote: ↑Thu Feb 14, 2019 9:49 pm
Can I do anything to make it use less resources?
stick a small time.sleep() in the loop
Yes I thought of this - but if I had, say a time.sleep(2), would I have to hold the button down for up to 2 seconds before it registered?
This fixed it, thank you... I just hold the button down until the screen comes on.
I wonder how small I can make the sleep interval....
Re: waiting for GPIO button press eating resources
Posted: Thu Feb 14, 2019 10:54 pm
by rpiMike
time.sleep(0.1) should work fine