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GPIO Toggling Performance
Posted:
Mon Sep 29, 2014 9:15 amby hackrid
Hi,
has anyone yet measured the frequency the GPIO can be toggled at?
I'm thinking of using one of these modules as a controller for a RGB LED strip with ws2811 LEDs which would require >800 kHz
Re: GPIO Toggling Performance
Posted:
Mon Sep 29, 2014 11:08 amby cnlohr
I was actually just wondering this. While it looked like it was humming along very quickly, I am worried the cache and interrupts may make 2811/2812(b) driving difficult. I will likely tackle this by Thursday or so.
Re: GPIO Toggling Performance
Posted:
Mon Sep 29, 2014 12:07 pmby RichardS
From **much** experience with 2812's, if there is ANY interrupts on at all, forget it!
Richard.
Re: GPIO Toggling Performance
Posted:
Mon Sep 29, 2014 12:27 pmby cnlohr
There's a lot of tricks you can play, like turning off interrupts when they're low and allowing them to be high for a while. Timing high-side of the 2812B's are much more lenient, however, it would be neat to see if we can just turn off interrupts entirely for long enough to drive 512 of those suckers.
http://cpldcpu.wordpress.com/2014/01/14 ... he-ws2812/