Free software for a wire diagram

Thread Starter

kcb4365640

Joined Apr 9, 2010
17
Hello. I am in the process of creating a customized circuit on 2 PC BOARD PAD-PER-HOLE (http://search.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=3662-9&stock=1). It will have several IC sockets (some 14 pin, 16 pin, etc.), a 40 position breakaway header on the one end (http://search.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=S2151E-20-ND), and a connector on the other end of the board that plugs directly into a connector (http://search.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=EDC307440-nd).

My question is whether anyone knows of a good computer program (preferably free, or at least offers a free trial) that I can use create a wire diagram, so it will be easier to physically wire the connections later? Before I have used Auto-CAD before, but it is very cumbersome since it is not designed for this. I would like to have something that is relatively easy to use as well.

Thanks in advance for anyone's suggestions.

Kevin
 

retched

Joined Dec 5, 2009
5,207
For your schematic design, try LTSpice. It is a very free, very powerful schematic capture and simulation program.
http://www.linear.com/designtools/software/ltspice.jsp


So you can build and test your circuit in the software to help along the design and troubleshooting process.

Eagle from CADSOFT is NOT free, but has an evaluation version that you can use. It is limited to board size, so If you can fit your components on the trial board size, it is good for you.

There are a few for linux which are pretty much all free.
http://pcb.gpleda.org/obtaining.html for instance.

more info here:
http://www.smps.us/pcb-design.html
 

SgtWookie

Joined Jul 17, 2007
22,230
LTSpice is great for simulation, but not for creating a PCB.

Cadsoft Eagle (demo) is great for single-schematic-per-capture and PCB design up to 2 layers and board size up to 3"x4" (approx). It's free for non-commercial users.

It's a bit quirky to learn, but once you learn it, it's quite powerful.

Unfortunately, there are currently no utility programs available to convert Eagle BOMs and netlists to LTSpice or vice-versa.

Sparkfun has a pretty good tutorial on Eagle, here:
http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=108
 

Thread Starter

kcb4365640

Joined Apr 9, 2010
17
Thanks for everyone's suggestions. I have downloaded LTspice, Eagle, and ExpressPCB, and have been experimenting with each one. It does seem that LTspice is good for simulation, but I think it is more than I need. I just need to create the circuit diagram so it is easy for me to make the physical connections.

It would be nice if I could just "import" the prototype board I am planning on using (http://www.vectorelect.com/Product/Plugbord/Layout/3662-9 Layout.pdf), and then I can "add" the IC sockets onto the board (e.g. 14 pin: http://search.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=ED57143-ND), breakaway header to the one side, etc. Then I can just "draw" the wires to corresponding pin locations on the prototype board. It seems to me that either Eagle or ExpressPCB would be the easiest to learn, but I am unable to really start this with either one of them? Any suggestions how I could do what Thanks for any help with getting me started.

Kevin
 

retched

Joined Dec 5, 2009
5,207
Did you read the tutorial that SgtWookie linked to?

I would also suggest using google to find tutorials and tips and tricks regarding the software you are learning.
 

rainyday101

Joined Sep 24, 2009
50
I started using ExpressPCB and love it. It's quick and easy to learn, especially if you've hand any CAD. Might not have all of the features, but makes great schematics. I also downloaded LTspice and have used the simulator many times. I love what I have been able to do with it and I am quite sure I've used about 1% of its abilities.
 

SgtWookie

Joined Jul 17, 2007
22,230
I failed to look at the protoboard you wish to use. The demo version of Eagle won't handle a layout that large. ExpressPCB will probably be a good bet for you.
 

mcgyvr

Joined Oct 15, 2009
5,394
diptrace is the best free schematic capture/board layout tool (with a paid version for increased pin/layer counts) Far easier to use than Eagle in my opinion
 

retched

Joined Dec 5, 2009
5,207
I second that DIPTRACE is a very powerful tool. I use it and I am no professional user.

It has very powerful checking capabilities with tons of math algos to check hundreds of aspects of the design.

QUITE powerful. You can make many layered boards and the auto functions are very good. you can choose auto layout and auto trace options that take ground planes in consideration depending on if it is a high or low speed board.

You can set and lock components (like jacks and POTs) to fit into premade housings and let the auto functions lay everything out. Trace width, angle, length, distance to other signal paths or power buss' and material are all taken into consideration.

They have videos to show you how to use it. I believe there is a 2000 pin limit on the free version. I would get a few hours experience on another package before trying to tackle Diptrace.
 

Thread Starter

kcb4365640

Joined Apr 9, 2010
17
Hello again. I am attempting to use ExpressPCB, but I am unable to set the size of the prototype board that I have? As you can from the drawing: http://www.vectorelect.com/Product/Plugbord/Layout/3662-9 Layout.pdf, it is 4.5"x6.5", and it contains the 44 position connector end. It also contains two buses along the edge that I would like to have with +5V, and GND. I have went through the tutorial, but I still don't see how I can "create" this board using either software program. Thanks for any suggestions on how I can model this card with either software program.

Kevin
 

beenthere

Joined Apr 20, 2004
15,819
To each his own, I suspect. I have used ExpressPCB to make any number of PCB's, and place them in a 10" X 12" panel. You may need to create components, but that is quite simple. I place components manually.

One thing - the yellow outline that appears has corners that can pull to whatever the maximum size is possible. 4.5 X 6.5 is well within the limit. You can simply create the layout and stretch the outline later, for that matter.
 

Thread Starter

kcb4365640

Joined Apr 9, 2010
17
Thanks for the info with the yellow outline. I missed that! I too am just placing the components manually, instead of using the ones they have in the component library.

One question I have is why I don't see the components I create in the schematic diagram (i.e. .SCH file) in the wire diagram (.PCB file)? The .PCB file should be "linked" to the SCH file, but I don't see the components in the custom library? Do I need to create one for each file? Thanks for the assistance.

Kevin
 

retched

Joined Dec 5, 2009
5,207
For custom components, you need 2 models. 1 for schematic and 1 for PCB. In the schematic design, you can choose where and what order you want the pin numbers in for a "cleaner" schematic, but when you go to PCB, they have to be ACTUAL.
 

Thread Starter

kcb4365640

Joined Apr 9, 2010
17
Thanks. I was doing the "actual" for the schematic file. I don't see what the point of "linking" the .PCB and .SCH files is then?
 

retched

Joined Dec 5, 2009
5,207
Well , if you had a 3000 component schematic, and are using it for simulation, it is much easer to make changes to new or updated boards.

Imagine if you wanted to change processors to one with different pin-outs.

If you only had the PCB layout, you would have a hard time doing all the routing. But changing it on the schematic will allow automatic changes on the PCB.
 
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