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Trying to add PLCC68 socket from the smd-special.lbr

konsolkongen

Hi. I'm new to Eagle. I know the very basics of how to use it, but I have some problems adding a part to my board. I wan't to add a PLCC68 socket, which is included in the smd-special library. I just want the empty socked and I can wire up all the connections manually.

 

However, the socket cannot be found when in schematics mode, where I would normally add it. I can only find it when in board design, and there I'm not allowed to add it. I get the error "Can't backannotate this operation. Please do this in the schematic!", which as I said is not possible because the part does not show up there.

 

Can I seriously not just add an unnamed socket to my board and have me wire up the connections manually? Do I really have to create a whole new part with every pin predefined? That would be insane, and incredibly frustrating for a newcomer like myself. I could see myself end up using hours figuring that out image

 

The specific part I'm trying to add is PLCC-68 SMTL-TT. It's for a Motorola 68000 on a Neo Geo MV-1C.

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  • 0

    Hi Martin,

     

    You do need to create a part (if one doesn't exist) to reflect what you want in the schematic, and then it will place the footprint in the board layout view. While your requirement is valid for very small circuits, it wouldn't scale to larger circuits without a high risk of error and is therefore a workflow that isn't supported in many CAD packages.

    Some early low-cost CAD packages allowed you to place and wire package footprints manually, and there are still some software packages which do this. I think Sprint-Layout supports the type of workflow you want to do.

Reply
  • 0

    Hi Martin,

     

    You do need to create a part (if one doesn't exist) to reflect what you want in the schematic, and then it will place the footprint in the board layout view. While your requirement is valid for very small circuits, it wouldn't scale to larger circuits without a high risk of error and is therefore a workflow that isn't supported in many CAD packages.

    Some early low-cost CAD packages allowed you to place and wire package footprints manually, and there are still some software packages which do this. I think Sprint-Layout supports the type of workflow you want to do.

Children
  • 0 in reply to shabaz

    Hi shabaz. Thank you for your reply. I do see the benefit in having the part properly defined for large runs, or parts you use regularly. For this one though it's a bit annoying as I don't ever plan on using it again image

     

    But at least I now know that this is the correct way, so there's no getting around it, as I would like to stick with Eagle. I have to figure out how to add a new part, and it will probably be handy down the line too.

     

    I have added the package? (the drawing from the smd-special library) to a new library, so I guess I need to figure out how to add the stuff that goes into the schematic view image

  • 0 in reply to konsolkongen

    Hi Martin,

     

    You'll need to create a symbol too, and then marry them together in a device.

    This is described better in the EAGLE PDF user guide (and various user youtube videos), but the diagram below shows approximately where you need to get to.

    Once this is done, you can add the device in a schematic, and then generate your PCB from that.

    image

  • 0 in reply to shabaz

    Thanks again. I was just messing around with that, without much clue what I needed to do.

     

    I have made a shape and all the pins in the symbol editor now. For the pins, is the green circle (like in your picture) supposed connect to, or face away from the part. Or does it not matter?

     

    I seem to have the drawing of the socket (the package) correctly copied from the other library, so I guess that will save a lot of time, as it should already have all the correct dimensions for the board view, right?

     

    I haven't been able to figure out how to connect the symbol and package yet, but it's getting late, so unfortunately it will have to wait for another day.

     

    Sigh... this was supposed to be just a few hours work and done. It's literally just the socket and some solder pads, nothing else... image

  • 0 in reply to konsolkongen

    Hi Martin,

    The center of the green circle signifies where the signal connection will be made to other components, so faces away from the part.

    It is often an assumption that the package correctly matches the part so for this reason I always create my own symbols, packages and devices for anything more complicated than a resistor/capacitor. I'm not saying it won't work out for you if you use it, but it may be good to check the positions of some of the pins to confirm they are in the positions you expect, same pitch, etc.

  • 0 in reply to shabaz

    Thanks again. I'll take a look at a guide, and hopefully I'll be able to figure it out in no time image