SD card reader issue with long cables

Hi guys,

I wanted to have much longer wires for the screen, because it is sometimes useful to be able to carry it around.
I purchased some 3 meters long RS232 cables as well as some 10 pin -> RS232 interface cables.

It works pretty well, except for one little (but quite important) detail: I don’t have access to the SD card files anymore. It detects that the card is inserted in the home screen, but whenever I want to print from SD, it says that there is no memory card.

I’ve checked the continuity of all the wires and everything seems to be fine. When I put the old wires back, it works again.
Any thought about how I could solve this issue?

Yeah there is a length constraint for sure. I sell mine at a 2’ length. I am pretty sure things get sketchy much past that. If you really want to try, run them by themselves and shield them if possible but I think you are going to need to cut them way down.

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Well, that kinda sucks…

I wonder why. Maybe this is a timing issue, the wires act like capacitors and this messes up the synchronization?

I wonder also if I could somehow separate the SD reader from the screen.
I could put the SD reader near the arduino and have the mobile screen with long wires, since other than the SD card I have no problem at all.

Not really sure yet how I could do that.

I think there is an option in marlin config file to slow the sd speed. That should help…

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Just buy a separate SD reader

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SPI_SPEED is the value.

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Thanks a lot, I’ll try that!

I’m not sure that this will work though, because it seems that this use too much pins. The LCD still needs a bit more to work properly (for instance, the encoder doesn’t work if only one cable is plugged)

I was going to ask if there’s any way to extend the LCD wires from the board. I guess this sort of answers my question. I’m having trouble mounting the Ramps away while still having the LCD in a convenient place.