Circuit Overlay Modules

24

Comments

  • I'm still waiting for the file from Parallax. They may not release them. I not happy that you template are on a .005. I can not work with that do do a layout in a timely manner. .025 would be better. I do not have my boards and calipers to take measurements.
  • Publison

    I can create a special program for you. Let me take another look.
  • idbruceidbruce Posts: 6,134
    edited 2020-09-01 - 22:40:20
    At a 0.025" grid alignment, the 16 pin header will be off by 0.010". If that is what you want, I would be more than happy to push the 16 pin header for you.
  • idbruceidbruce Posts: 6,134
    edited 2020-09-01 - 22:49:28
    The only time that you need the 0.005 grid is when you connect to the I/O pins of the Propeller. Besides that, you can do all of your other work in any grid size you want.

    EDIT: And that is just for final attachment. The I/O pins break on a 0.10 grid vertically, it is just that last connection horizontally.
  • I can do that in Diptrace and send the file to you.
  • If that is the case, it needs to be pushed towards the 13 pin headers. If you push it away from them, the discrepancy will increase.
  • Publison

    Let me look at something.... I have been referring to the board the last few comments
    The only time that you need the 0.005 grid is when you connect to the I/O pins of the Propeller. Besides that, you can do all of your other work in any grid size you want.

    EDIT: And that is just for final attachment. The I/O pins break on a 0.10 grid vertically, it is just that last connection horizontally.

    Let me see if the schematic is set on 0.005.
  • The schematic should be good to go at a 0.10 grid. It is just the board, with the final connection to the I/Os
  • idbruceidbruce Posts: 6,134
    edited 2020-09-01 - 23:08:44
    Or...... You could push the 16 pin header towards the 13 pin headers to where it lines up on a 0.10 grid, do your work, and then when you are all done, before sending off the design files, push it back where it needs to be :)
  • It certainly would have been much easier with overlays, if they had pushed the 16 header away from the 13 pin headers another 0.035 (in.). However I am sure they did not foresee this thread. :) They wanted it to look nice :)
  • If JP3 and JP5 could be shifted .005 right or left, that would fit a better grid. I don't know it the physical fit would work. Should work.
  • If JP3 and JP5 could be shifted .005 right or left, that would fit a better grid. I don't know it the physical fit would work. Should work.

    I disagree...... Why move two headers, when moving one will accomplish the same task.

    If you move the 16 pin header in either direction by 0.005, it will allow a 0.010 grid.
  • I got it. because of the board edge... Like I said, the 16 pin towards the 13 pins
  • PublisonPublison Posts: 11,661
    edited 2020-09-01 - 23:31:51
    Not if the origin remains the same.

    PS cross posted.

  • Publison

    Just attach the files you want, EAGLE or DipTrace, and I will make them easy access for you.
  • gottya.
  • Unless of course you want them in EAGLE, in which case I could nudge it for you.
  • I'm going to nudge the Diptrace tomorrow.. Time for dinner. :)
  • Have a good night.
  • idbruceidbruce Posts: 6,134
    edited 2020-09-03 - 00:30:44
    As I have said many, many times, I am not an electrical genius, and I am very sure that this schematic is very far from looking professional, but it looks pretty decent to me :)

    I do believe that I am starting to get a handle on the EAGLE again, or at least the schematic editor. I will be designing the board very shortly :)

    8825%20schematic.jpg
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  • idbruce wrote: »
    As I have said many, many times, I am not an electrical genius, and I am very sure that this schematic is very far from looking professional, but it looks pretty decent to me :)

    I do believe that I am starting to get a handle on the EAGLE again, or at least the schematic editor. I will be designing the board very shortly :)

    A schematic does not have to be a work of genius or a work of art. It needs to be uncluttered and clearly show how the components are connected. Yours does that very well. Back when microprocessors were starting to be used in instruments they typically had a motherboard and several daughter boards. at that time my favorite style of schematic was one where the signals were grouped by function (address, data, control, misc, etc) and represented by a bold or colored line. That removed a lot of clutter from the schematic, and with the inclusion of a netlist in the manual made troubleshooting a system with a dozen or more boards and 400 - 500 chips feasible. That style of schematic isn't really needed as much with small Micro-controller boards since they generally have a small number of components, but it would make for a less cluttered and easier to follow schematic.
  • idbruceidbruce Posts: 6,134
    edited 2020-09-03 - 17:38:18
    Kwinn

    Over the last several days, I have been going back and forth over three different schematics, two of them were single drawing schematics, and the other had the schematic broken up by significant portions. I think I actually prefer the single drawing schematics, because it seems easier for me to comprehend the overall view, but I can understand where it might be highly beneficial to someone with a strong electronics background.

    Anyhow, here is the finished schematic. Time to see how well I can do with the board editor.

    DRV8825%20Overlay.jpg
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  • Looking good Bruce. I have been off line trying to close on a house. Will pick up later.
  • idbruceidbruce Posts: 6,134
    edited 2020-09-04 - 03:37:05
    The only time that you need the 0.005 grid is when you connect to the I/O pins of the Propeller. Besides that, you can do all of your other work in any grid size you want.

    EDIT: And that is just for final attachment. The I/O pins break on a 0.10 grid vertically, it is just that last connection horizontally.

    Now that I have started working on my board, I can clearly see that was a misconception :) Of, course I will make that a true statement in the end, but for now, it is false :) I lied :)

    To allow snapping on a 0.10" grid, except for final connection to the I/O pin of the Propeller, I will have to increase the board size for the overlays. I am starting to look into this now :)
  • I will be testing out new board dimensions and header centers with the following parameters:

    NEW BOARD DIMENSIONS
    2.3 X 1.6

    NEW HEADER CENTERS
    JP2 - X 0.9 Y 2.15
    JP1 - X 0.115 Y 1.15
    JP3 - X 0.9 Y 0.15
  • It's wise to use a metric grid when dealing with such fine QFP pitch.
  • idbruceidbruce Posts: 6,134
    edited 2020-09-04 - 21:36:59
    Evan

    I am sure you are correct, but I am still learning the hard way :)

    I will know soon enough, because my components are placed :)

    board.jpg
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  • Oops, I assumed you were doing a board with a prop2 on it. I only dream prop2 :)
  • Placement looks good, but I was having a hard time with traces landing on center of pads.
  • It's wise to use a metric grid when dealing with such fine QFP pitch.

    I could be wrong and I most likely am, but I do not foresee it as a major ordeal. Worst case scenario as I see it, the connection of the trace to the pin may be off by 0.0005~0.001 in., and having a little offset. However, I do agree it would be cleaner and more accurate in metric.
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