SD card reader issue with long cables

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This topic contains 7 replies, has 5 voices, and was last updated by  Peter A Mills 4 months, 2 weeks ago.

Viewing 8 posts - 1 through 8 (of 8 total)
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  • #33185

    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?

    #33186

    Ryan
    Keymaster

    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.

    1 user thanked author for this post.
    #33187

    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.

    #33189

    Martin DB
    Participant

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

    1 user thanked author for this post.
    #33197

    David Walling
    Participant

    Just buy a separate SD reader

    https://www.amazon.com/SainSmart-RAMPS-Breakout-Board-Reprap/dp/B00E8BY3O6

    1 user thanked author for this post.
    #33207

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

    SPI_SPEED is the value.

    1 user thanked author for this post.
    #33255
    I think there is an option in marlin config file to slow the sd speed. That should help…

    <span class=”et_quote_sign”></span>

    SPI_SPEED is the value.

    Thanks a lot, I’ll try that!

    Thanks,
    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)

    #33272

    Peter A Mills
    Participant

    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.

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