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Eagle Cad is driving me crazy. — Parallax Forums

Eagle Cad is driving me crazy.

Martin_HMartin_H Posts: 4,051
edited 2014-01-05 13:14 in General Discussion
Rather than trying wire wrap for a digital circuit, I'm giving PCB design a try. The good news is that it has a Propeller chip in their library. The bad news is that I want to use a 74lc244 from their library, it should have eight inputs, but the program only shows four in schematic mode. But when I switch to board mode it is the correct eight buffer chip.

Does anyone know of any good tutorials which might demystify this program?

Thinking about how much my time is worth I will probably bite the bullet and send away the board. That should be a learning curve as well.

Comments

  • jazzedjazzed Posts: 11,803
    edited 2014-01-04 15:15
    Sparkfun.com has many, many Eagle tutorials.

    Often parts are broken down in to sub-sections if there is duplicate logic in them. For example, a 74ls04 has 6 inverters, but you only get one at a time. This is common in schematic capture history back to Valid GED and probably others before that.
  • Martin_HMartin_H Posts: 4,051
    edited 2014-01-04 16:14
    Thanks Jazzed, I'll look into tutorials on SparkFun.
  • T ChapT Chap Posts: 4,223
    edited 2014-01-04 17:34
    It would take too long to discuss in the forum. If you want to ring me tomorrow I can walk you through it. I like Eagle after having learned it the hardest possible way, never doing the tutorials or reading the manual. One thing I love is not messing with gerbers to make boards, just upload the .brd to sunstone,com and select file conversion. Boards at my door in 48 hours. I work on library parts a lot but couldn't begin to explain it in written format. Once you get it, it is easy.

    BTW, when you select an inverter and place it, you are only placing one element of the part. You will need to place it again to insert the next part of the IC, and so on until you wrap around to the next IC. Also, in some cases the library part does not show the power to the IC, you have to "invoke" the power pins to show up. If the power pins were named exactly as you are naming your power on the board(vc, vdd, vss, 3v3 etc), then it will connect to the proper place even if you don't see the power pins on the schematic. I prefer to always see the pins to everything.

    If you have a chip with 8 inverters on it, and you only place 1 of the inverters, you will not see the other 7 inverters i the schematic and the inputs will be floating when you make the board. So be sure to know how many parts exist in an IC, place and confirm all the parts are seen in schematic view, take unused ins to GND. If you place only one element on the schematic, the board view cannot separate the elements and will show pads for the full chip.
  • $WMc%$WMc% Posts: 1,884
    edited 2014-01-04 18:28
    I have found DipTrace to be more user friendly.
    '
    Theirs a free ware version that works great.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-01-04 19:06
    $WMc% wrote: »
    I have found DipTrace to be more user friendly.
    '
    Theirs a free ware version that works great.

    +1

    I used SparkFun's tutorials when I was trying to learn to use Eagle. I thought the tutorials were pretty good but when Parallax stated a preference for DipTrace I decided to give it a try. I was a bit reluctant about trying DipTrace since I had already put so much effort into learning to use Eagle. I was very glad I switched. It did not take long for my ability to design a PCB in DipTrace to exceed my ability to design a PCB in Eagle.

    I found designing in Eagle to be frustrating while I really like designing PCBs in DipTrace.

    There are several fab houses that will accept Eagle files without the need to produce gerber files but the gerber files are very easy to produce in DipTrace. It's just takes a couple of clicks of the mouse to export a design.

    If you're still new to learning to use PCB design software, I strongly recommend switching to DipTrace.
  • Martin_HMartin_H Posts: 4,051
    edited 2014-01-04 19:38
    T Chap, that explains why I placed two 74LC244's but only saw one in board mode! So I'm good to go with that. I followed the tutorial and I was able to create a bus and bind it to pins on the Propeller and the 74lc244.

    Duane, I have a few hours into this design, so I'll finish it in Eagle Cad and try Dip Trace on the next one.
  • Dr_AculaDr_Acula Posts: 5,484
    edited 2014-01-04 19:42
    Image2.jpg


    Screenshot with the invoke button, half the 244 and the power supply pins.

    I like eagle because even though the learning curve is steep, so many people use it that it is easy to find answers. eg I just changed a board from 2 layers to 4 layers and it only took a few minutes on google to get up to speed with this.
    Image2.jpg
    578 x 732 - 41K
  • T ChapT Chap Posts: 4,223
    edited 2014-01-04 19:51
    When you place parts, run nets, etc, do not assume that the connection was made even though the net or pin may look overlapped. After placing the part or net, take the pointer tool and click on the part a few times to insure that the net "lights up" meaning there is a real connection. This may be obvious after you run the rats nest and see that some parts did not route.

    If you intend to make just one board versus a panel with multiple boards on it, that is fine as is. But if you intend to copy and paste the board into a panel, be aware that you will see that all the names have been incremented if they contain a number at the end of the name. IE on a board, R1 will become R1, R2, R3, etc for every new multiple on the panel. Therefore, use the ULP called "panelize" after you finish the board and before you copy and paste to a panel. Then, on the panel you submit to the fabricator, do not include the tNames layer in the silk screen list. Use the newly created copies of the names that appear (in yellow typically) at the bottom of the layers list, and these new names will not increment on the panel after multiple copies.

    Working in panels saves a lot of money for quick turn boards, even though you have to cut them up after. However, for then other services, you may find the running a single board may be cheaper since they can stick small boards on other orders that did not fill up the 12 x 14 maximum space available,
  • RDL2004RDL2004 Posts: 2,554
    edited 2014-01-05 07:17
    Eagle was fine when it was practically the only choice. Diptrace is so much better that I think the only reason Eagle is still around is momentum. Almost anyone with basic computer skills can add their own parts in Diptrace immediately. It's so easy that I basically don't use the built in libraries, I prefer to just make my own. That way I can have my schematics look exactly the way that makes sense to me. It's trivial to make both functional and chip-centric version schematic symbols for a part. If you're designing circuits for a breadboard or perf board build, starting from a chip-centric schematic is much easier. You can draw your schematic to be very similar to the final circuit layout.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-01-05 07:43
    T Chap wrote: »
    When you place parts, run nets, etc, do not assume that the connection was made even though the net or pin may look overlapped.

    Apparently I'm not the only one to have had this problem. This was one of the things about Eagle that drove me crazy.
  • T ChapT Chap Posts: 4,223
    edited 2014-01-05 07:52
    Well, this is one of those few things that once you know about it, as you place the part you just click on it twice and see the nets light up and you are fine. I have heard all the opinions pro and con, but I guess I just know it so well that I don't want to change even if something were better, that other thing would still be some learning curve that I don't see a benefit for yet, and I like working on the mac.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-01-05 08:08
    T Chap wrote: »
    Well, this is one of those few things that once you know about it, as you place the part you just click on it twice and see the nets light up and you are fine. I have heard all the opinions pro and con, but I guess I just know it so well that I don't want to change even if something were better, that other thing would still be some learning curve that I don't see a benefit for yet, and I like working on the mac.

    I doubt I'd change if I had learned Eagle as well as you have either. But since I was still relatively new to Eagle, it made sense for me to switch.
  • jazzedjazzed Posts: 11,803
    edited 2014-01-05 08:21
    Having a demo video is good. I'm not sure if Eagle has one or not, but I learned Eagle long ago.

    Watching the dip-trace video, I could see advantages and disadvantages to both systems.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-01-05 09:35
    The biggest problem for Eagle CAD beginners is that the libraries of components are vast. It gets really hard to find what you want. And to add insult to injury, if you want to create your own components to avoid that problem, the creation process is a bit tedious.

    The actual schematic creation and the wiring of a board is pretty straight forward if you can get past the above.
    There is a trick to designing single sided board. I tend to use 0 ohm resistors to get my placement the way I want it.
  • tritoniumtritonium Posts: 543
    edited 2014-01-05 13:14
    Hi
    RS, (RadioSpares), an electronics supply firm has released some free design packages, one for PCB's and one for CAD
    They have an online magazine here....

    http://www.designspark.com/eng/nodes/view/type:design-centre/slug:designspark-magazine


    from which you can download free for commercial or home use the PCB design software here...

    http://www.designspark.com/eng/page/designspark-pcb-home-page


    I haven't tried it so I can't recommend it but... perhaps one of you have??


    Dave
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