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Forum Index : Microcontroller and PC projects : Question regarding RP2350 with PSRAM

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dddns
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Joined: 20/09/2024
Location: Germany
Posts: 380
Posted: 06:29pm 28 Feb 2025
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This question is regarding HDMI and I do not want to spam another thread:

Is it possible to increase the color depth in the current HDMI modes while leaving the clockrate unchanged? Is it just a question of RAM amount? What is the future plan?

I'm asking because I would of cause not hesitate to exchange my ssd1963 LCD against an IPS panel with the size of my choice if it would be possible and implemented.. ..I would like to know to have a plan for myself on how to go on further.

Of cause everybody is invited to answer (the main question)!
 
matherp
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Joined: 11/12/2012
Location: United Kingdom
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Posted: 07:02pm 28 Feb 2025
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No: PSRAM isn't fast enough to use as a framebuffer
 
lizby
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Joined: 17/05/2016
Location: United States
Posts: 3326
Posted: 07:47pm 28 Feb 2025
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Deleted--posted in wrong thread.
Edited 2025-03-01 05:50 by lizby
PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed
 
dddns
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Posted: 07:58pm 28 Feb 2025
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  matherp said  No: PSRAM isn't fast enough to use as a framebuffer

Thank you, I think I got it.
The physical framebuffer which delivers the actual picture is realized with the RAM of the pico and processed through the pico in contrast to LCD, where this job is done by the display controller and the internal RAM.
 
dddns
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Posted: 08:19pm 28 Feb 2025
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Never the less PSRAM would be fast enough to have 25frames/s at about 160x96 in rgb888 on the ssd. That's almost the size ov7670 delivers. So a "videoeditor.bas" with the option of creating a video with live pictures is not unthinkable :)
I mean with only the use of the blit command.
Edited 2025-03-01 06:21 by dddns
 
dddns
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Posted: 05:11pm 01 Mar 2025
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  dddns said  Never the less PSRAM would be fast enough to have 25frames/s at about 160x96 in rgb888 on the ssd. That's almost the size ov7670 delivers. So a "videoeditor.bas" with the option of creating a video with live pictures is not unthinkable :)
I mean with only the use of the blit command.


Wrong nonsense, sorry.
I found, that only a rp2350 with 8Mb PSRAM and an ILI9341  LCD will be enough, to have roundabout amazing 2.5seconds of 240*130 RGB888 fully flicker free video sequence in 25 frames/s!

This is possible already for months since the implementation of PSRAM.
I saw trees, but not the forest.
Edited 2025-03-02 03:32 by dddns
 
dddns
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Posted: 05:45pm 01 Mar 2025
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I did a proof of concept and have a 1,3sec sequence running only by using blit.
There is a command "blit,x,y,x1,y1,w,h" but sadly only to copy content within the physical screen. Copying between blit buffers seems to be not possible.
 
dddns
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Posted: 10:26am 03 Mar 2025
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Sample of reading 32 blits of 260x190(that's max for 9341@25frames/s) extracted .bmp frames and then displaying them in
32/25 = 1.28sec length clip on a PGA2350 and ILI9341. Memory shows:
> memory
Program:
  1K ( 1%) Program (37 lines)
255K (99%) Free

Saved Variables:
 16K (100%) Free

RAM:
  1K ( 0%) 5 Variables
4632K (71%) General
1815K (29%) Free


so there is some space left but the blit slots are saturated.
I think it would be a real valuable improvement for everyone using LCDs, to increase the number of available blit slots and to extend the existing
blit x1,y1,x2,y2,w,h

with parameters for source and destination.
Beside just playing a sequence as video, it would be easily possible to generate amazing effects like let a photo realistic man walk through the picture or a digital picture frame with nice animations.

ILI9341.mp4.zip
 
Volhout
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Joined: 05/03/2018
Location: Netherlands
Posts: 4918
Posted: 01:43pm 03 Mar 2025
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Hi dddns,

Look at "blit memory".

Volhout
PicomiteVGA PETSCII ROBOTS
 
dddns
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Joined: 20/09/2024
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Posted: 02:13pm 03 Mar 2025
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  Volhout said  Hi dddns,

Look at "blit memory".

Volhout


Did not try that yet as I read the manual and thought, that it is only rgb121
Will do :)
 
Volhout
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Posted: 02:21pm 03 Mar 2025
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Blit memory may be "tricked" into doing what you want.
If you just need to copy blocks of memory, use "memory copy".

Volhout
PicomiteVGA PETSCII ROBOTS
 
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