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raspberrypi / pico-playground

BSD 3-Clause "New" or "Revised" License
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TURBO_BOOST breaks vga color #32

Closed barbiani closed 1 year ago

barbiani commented 1 year ago

Hi,

I have noticed that enabling the TURBO_BOOST define breaks the correct colors display on the flash_stream sample vga_mode_640x480_60 .

Without TURBO_BOOST, the number is crisp and the blue gradient is perfect.

With TURBO_BOOST, a blue gradient turns to like 64 color dithered green.

Also, white blobs are leaking red pixels to the right.

Are these artifacts usually caused by vga timing error?

Thank you.

image

sfranzyshen commented 1 year ago

just a guess but looks like it's related to set_sys_clock_khz() ... see other examples below

https://github.com/raspberrypi/pico-playground/blob/e551a2d7606a468b00299e408ab44e62947926f9/scanvideo/mandelbrot/mandelbrot.c#L277 https://github.com/raspberrypi/pico-playground/blob/f0ce80c9d282b45fd1a3f882d92bce17bea4826d/scanvideo/sprite_demo/sprite_demo.c#L174

barbiani commented 1 year ago

Looks like set_sys_clock_khz(300000, true); fixes the flash stream demo.