How do you orient you component pinouts on the schematic?

Discussion in 'General Electronics Chat' started by spinnaker, Nov 2, 2012.

  1. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
    When I go to use a new part on a schematic, I usually re-orient the pins so they are oriented on the schematic part as they are oriented on the PCB.

    When it comes to parts with high pin counts such as MCUs, this helps me plan what pin of the MCU to connect to which component.

    But I am seeing where this technique can be time consuming reorienting the part put might not make for the best layout when it comes to the schematic.

    How do you orient you component pinouts on the schematic?

    I was using Express PCB but I have moved to Diptrace recently.
  2. nerdegutta


    Dec 15, 2009
    I'm using Eagle.

    I try to make the schema clean and structured by blocks. And I put the components on the schema the way it is going to be on the board. I find it easier to design the schema/board that way, because the design process has already started in my head.

    See attachments for some examples.
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    Remember also that you are free to redesign any schematic symbol. Say using a square for high pin count PICs. If you feel this will make your schematic more easy to read
  4. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    I'll typically draft schematics in logic blocks, using single line drawings. That often results in the MCU not being drawn as a whole, but only the blocks associated with that particular logic. Even for MCU specific logic such as clocks, resets, etc., only those lines involved appear.
  5. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
    Yep that is pretty much what I do. I have found that laying out the part on the schematic as it is on the board really helps with pin selection on multi like mcus.
  6. WBahn


    Mar 31, 2012
    A big part of the issue is that the schematic is being used for two very different purposes - to capture the logic of the design, and to capture the physical implementation of the design. In general, doing one better results in the other being done worse.

    As a rule, I prefer to have my schematics reflect the logic of the design, but it is certainly nice to be able to plan physical connectivity in the schematic as well. If I were specifying a new schematic capture tool, I would want to have two views -- a logic view and a package view -- that are hard linked so that making changes in one is reflected in the other. But beyond that you are free to organize them independently. I would have it so that you can have them open in two different windows and as you highlight a part or trace in one the corresponding part or trace is highlighted in the other. Carrying it a step further, I'd like to be able to have a third window with the actual layout and have the same behavior.

    My guess is that there is already something out there that has something pretty close to this, but probably only in the higher end of the tool chain.