Baywatch shifting image on display

[Rene368]

On 11/30/2021 at 2:37 PM, lucky1 said:

Please try

I tested the colorization file you exported. The result was excactly the same as before, see the video.

 

I also tested a shorter cable for the HUB75 connector. I took a before and after picture. The picture with the rainbow ribbon cable is the short one.

This also did not change anything.

 

I aslo removed the Nucleo and found out I did not shorten the HUB75 header pins (picture).

I will also shorten these pins just to be sure they are not going to function as antennas and will try again.

 

Lastly I will try different brands/types of micro SD cards to see if this changes something.

 

To be continued.....

 

 

[lucky1]

What you could also try is using the external HUB 75 connector and connect to the first panel with a cable instead of the downside connector.

 

[Rene368]

An update.

 

I did shorten these pins and tested again. Sadly still shifting.

 

Then I tried the external HUB75 connector. Also still shifting.

 

Lastly I tried 4 different micro SD cards with the original colorization files. This time there was a change. The 4 micro SD cards had all different results. I will list them with brand, type and result:

- Samsung EVO 128GB (UHS 3, SD XC 1) (made a 22GB partition with the files on it): This was shifting less then the original Sandisk 8GB in attract mode, but still noticable.

- Generic 8GB china (no speed class): This one was shifting really worse, even worse then the original Sandisk 8GB.

- Sandisk 2GB (no speed class): This one had the same text layout as the 2GB Samsung I tried earlier so I had no hope. But this one was pretty good, also in game.

   The shifting was almost gone in al frames. Sometimes it will come back, but it's much better with this one.

- Kingston 8GB (Class 4, SD HC): This one was about the same with shifting as the original Sandisk 8GB.

 

So there is progress in my opinion. Hope we are near a solution.

I made a video of the shifting with the Sandisk 2GB. You can see it shift twice during this video. 

I also attached a photo of the Sandisk 2GB, which was much better.

 

What could be the next step to try?

 

 

 

[lucky1]

The only information I can give you is that depending on the speed type of the SD card the clock frequency of the SDIO bus is adjusted.

So it is definitely cause by some signal interference between the SD card signals and the hub 75 port

[Rene368]

Is there anything I could test/measure to resolve this problem?

Would I find something if I measure, let's say, the clock signal from Hub75 & sd card with an oscilloscoop for example? Just as a start.

[lucky1]

9 hours ago, Rene368 said:

Is there anything I could test/measure to resolve this problem?

What I would test is cut the traces to the SD card reader directly at the nucleo pins on the shield and attach it "externally" with short wires to the upside connectors of the Nucleo to see if it changes anything.

 

[Rene368]

Well it's been a while.

I have measured with an oscilloscoop the HUB75 signals. They looked good.

Then I measured the signals from the SD card. They were also fine. 

I talked to my electrical engineering teacher what it could be and we could not figure it out, at first.

But then I saw that also when in some scenes the display shifted, the image also lost it's color. 

So I thought: this could only happen when the incoming signal is not good.

The only thing that was left was the 74LS123N for the clock signal from the pinball.

I replaced it with a new one and the shifting stopped.

Also with the SD card were there was lots of shifting to be seen in the past. Nothing with the new 74LS123N.

 

So my problem is fixed.

thanks for thinking along, Lucky1!😄