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pimoroni / pimoroni-pico

Libraries and examples to support Pimoroni Pico add-ons in C++ and MicroPython.
https://shop.pimoroni.com/collections/pico
MIT License
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pico_display_demo sleep (why?) #1001

Closed peardox closed 1 month ago

peardox commented 1 month ago

I just made a small tweak to the pico_display demo for the pico display pack

I noticed the code has sleep_ms(1000 / 60);

I set a variable to time_us_64() at the start of the main loop then calculated the elapsed time (i.e. frame time) at the end of the loop where the sleep is

The elapsed time was in the 62700 us region (fluctuates slightly) which is about 16 FPS

The sleep adds an extra 16667 us to the frame and is far less than the implied 60FPS it's seemingly trying to limit

OK, some screens could potentially go > 60FPS but surely it'd be better to at least check if the frame time was under the limit before adding more delay? Better in such cases would be to calc a more accurate value for the sleep....

Gadgetoid commented 1 month ago

It looks like a relatively old example into which not much thought was put. Could probably use some TLC, albeit I'd reserve that for after the PicoVector rewrite has been merged: https://github.com/pimoroni/pimoroni-pico/pull/853

Accurate frame pacing is probably somewhat outside of the scope of a simple API demo, though, but could be nice in a standalone example.

peardox commented 1 month ago

Removing the code that draws a load of trangles to create a sort of windmill effect so you've just got the bouncing balls left and removing the sleep increases the speed to > 60FPS - making it a bit more realistic

But, yeah, the display demos prob need a bit of an overhaul

peardox commented 1 month ago

Covered more fully in other issues