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RPi 2 and an SPI-based 4" LCD screen (and MAME)

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MacGyver:
Has anyone actually gotten an SPI LCD screen to work at a framerate near to correct for MAME?
I have read everything from everywhere and it looks like anyone making a RPi project is using an HDMI based screen and so their framerates look perfect. (so does mine on my LCD monitor)

I have tried for days to get my 4" Waveshare SPI-based screen to run at a speed close to fast enough to run Galaga or Ms. Pacman and the best I can get is about 10-15 FPS.  (Mame says it's at 33-65%, but it doesn't look that way)
I have tried altering the module settings to run at 20FPS and matching that in Advance mame.
I have tried doubling and quadrupling the timing to the screen from 11 all the way to 44 and the MS from 250 to 125, the FPS hard coded from 10 to 60, the speed from 16mhz to 60mhz. (init=-1,0xb0,0x0,-1,0x11,-2,250)
I have tried vertical and mame not rotated. (0x36,0x88)
I have tried horizontal and rol. (0x36,0x28)
I have tried using fb0 and framebuffer coping it to fb1, with and without DMA, in the foreground and background.
I have tried the LCD manufacture's image, I have built a brand-new Raspian from the website and modified it to run the screen, both look the same.  (both running fbtft and flexfb, with and without the touchscreen and fbcp)

Nothing gets the framerate to anything usable in an mini arcade cabinet.

I thought it would be a piece of cake as there are thousands of these things available for sale everywhere..  Is it something I'm doing wrong.  It can't be that all these projects are using RPi2 and HDMI or RPi1 and composite out can it?

It has to be me. Please help.  :dunno

dgame:
What resolution is the screen? I read somewhere on Adafruit that the 320x240 screens have better refresh rates than  480x320.

They set the HDMI output to 320x240 pixels, to exactly match the TFT resolution for the framebuffer copy.


--- Quote ---A 320x240 pixel PiTFT display (2.8" resistive, 2.8" capacitive, 2.2" HAT). For gaming we won’t be using the touchscreen features, but still need to distinguish among the various models. The 3.5" PiTFT (480x320) is not recommended for this project — more pixels means slower refresh.
--- End quote ---
https://learn.adafruit.com/running-opengl-based-games-and-emulators-on-adafruit-pitft-displays

MacGyver:
It's a 4" Waveshare at 480x320, so that's probably what it is (156k versus 76k pixels).   It makes sense, I just wish it wasn't true.

Can anyone confirm that their 320x240 SPI screen works at a full speed, so I don't waste another $50.  I was trying not to get a 5" HDMI because a 4" fits perfectly in my project.


It's a $20 Japaneses coin bank.

vwalbridge:
I never had to worry about any of the things you are describing with my Coleco tabletop. Plays games just fine on the screen I got. However, I used Windows. See Micro Donkey Kong link in my signature to see what screen I used.

MacGyver:

--- Quote from: vwalbridge on January 25, 2016, 08:17:10 am ---Found 4.3 inch HDMI LCD screen from eBay...

--- End quote ---

That's what I figured.   I looked at your build before, it was one of the one's that inspired me to try to make one myself.

I just didn't realize how bad of a performance hit the SPI interface would have on a 480x320 screen.  I wonder if I could find a HDMI to raw LCD controller interface for the 4" and switch it over?  I wonder if I should keep throwing good money after bad or just cut my losses and try to find a ready-made 4" HDMI LCD.  Could a Pi even output at such a low res on the HDMI port?

Any ideas?  Or a source for a 4" HDMI ready Pi compatible screen?

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