Software to organize messy schematic

[Leros]

I'm trying to reverse engineer a PCB. I'd like to draw the schematic onto the computer in the same layout as is on the PCB. Obviously this will be nearly indecipherable as the nets will be all over the place. Does anybody know of any software that will organize the schematic to minimize crossed nets to make the circuit more readable?

 

[pcgeek11]

I don't think that exists.

Hand drawn schematic - Feed to PC - Program interprets what you drew into a working organized schemtic.

Not going to happen.

 

[Leros]

That's not quite what I'm thinking.

I want to draw my schematic on the computer using a standard computer schematic design tool (Eagle CAD, etc). But I want to lay out the components as they are on the PCB so it is easier for me to manage. Since I'm working with a double sided PCB with lots of vias, there are many many overlapping wires. I want to be able to run some sort of algorithm to relayout the components so that the wiring overlap is minimized. This would help me to understand what is going on.

I know such software is possible, because you see algorithms for laying out components with minimal wire overlap when you do an automatic PCB or IC layout. I'm just not sure it exists.

Whoever designed this PCB did not make the layout elegant at all, so there is an absolutely ridiculous number of vias which means the number of overlapping wires is absurd.

 

[pcgeek11]

I see what you mean now, but I still don't think this software exists. I think that the only alternative is to beg for the engineering sheets for the board from the Mfg, ( which the odds are very small of getting them ). Or spend countless hours tracing them out by hand. Sorry I hope you find what you are looking for.

 

[NickelPlate]

It sounds like maybe what you are describing is an autorouter. However you will still need to place the components on the board manually and the autorouter is supposed to route the traces for you, although they don't always do the best job. I know of no PCB layout software (and I've used quite a few) that completely automates the process.

I'm assuming this is at the consumer level. You're most cost effective option would probably be Cadsoft Eagle http://www.cadsoftusa.com/

It has a free version but you're limited in board size and number of nets. It's the cheapest of any of the schematic capture board layout packages. All the rest, PADs, Altium, OrCAD will cost you many thousands of dollars for a single seat.

 

[Modelworks]

There are plenty of layout packages but most are expensive. I use proteus.
http://www.labcenter.co.uk/index.cfm

The demo does autorouting too but I think it blocks saves so not sure how useful that would be.



I forgot about kicad. I remembered reading on the piclist about alternatives and most of the EE there recommended it.
http://kicad.sourceforge.net/wiki/index.php/Main_Page

KiCad is an open source, multi-platform EDA (Electronic Design Automation) package. It will capture your schematics, build your parts libraries and lay out your PCBs. It runs under Windows, various flavors of Linux and has been ported to the Mac OSX.
KiCad consists of a project manager and four main programs:
kicad - the project manager.
eeschema - the schematic editor.
cvpcb - the footprint selector for components used in the circuit design.
pcbnew - the PCB layout program.
gerbview - the Gerber (photoplotter documents) viewer.

 

[corkyg]

Before I retired, we used OrCAD software for PCB design and production. That was years ago, but, it probably has progressed. I see there are even free downloads for older versions. Google OrCAD.

 

[Leros]

You guys don't understand what I'm trying to do. I know how to design, place, and route PCB boards.

I have an existing PCB board. I'm trying to analyze the PCB board and come up with a schematic so that I can alter the functionality of the device. The PCB board is a double sided board with an absurd number of vias which makes tracing connections very hard. You might go through 5-15 vias to go from pin to pin between components.

If I could draw my schematic, laying out my components in the same manner as they are on the PCB, it would make it much easier to make sure that I am drawing the schematic correctly. Doing this would cause the wires between the components to be overlapping in a ridiculous way.

I'm wondering if there is software out there that can take a messy schematic and clean it up. I mean, replace the components within the schematic as to minimize the wire overlaps.

 

[Modelworks]

I'm wondering if there is software out there that can take a messy schematic and clean it up. I mean, replace the components within the schematic as to minimize the wire overlaps.

Most any layout software can do that.
You place the components on the schematic about where they are on the board. Then connect them one by one, it doesn't matter if they overlap or how messy it is. Next export the design as a netlist to the routing software. Tell it to autoplace components. Once it has done that you can clean up any routes and export the schematic back to the capture program.