Cheap Schematic Capture

[Joel Koltner]

Hi Brad,

"Brad Velander" <bveland@SpamThis.com> wrote in message
news:g6rtj.49648$FA.37085@pd7urf2no...

As for pin/gate swapping, I never use the automatic features because they
don't intelligently apply any details about the routing, just simple
manhattan distance minimizations. Which are usually definitely not routing
optimized and no software can do that that I have seen.

Agreed, although I often find that Manhattan-distance optimized pin/gate
swapping is *closer* to "routing optimized" than just whatever happens to pop
out from the schematic in the first place.

I have a great deal of respect for really good PCB layout guys (of which I'm
not one )... it's amazing what they can "see" just by looking at a rat's
nest relative to most people.

---Joel

 

[Brad Velander]

Joel,
Your impression of the OP was obviously greater than mine. I sensed that
he was at best a hobbiest but since he didn't already have a tool, I
surmised that most tools and functions would simply bog him down. Not to say
that he may not be very intelligent, I just know how the average person gets
bogged down learning the nuances of a CAD program and most don't do get it
right when they do get through it.

As for pin/gate swapping, I never use the automatic features because
they don't intelligently apply any details about the routing, just simple
manhattan distance minimizations. Which are usually definitely not routing
optimized and no software can do that that I have seen.

--
Sincerely,
Brad Velander.

"Joel Koltner" <zapwireDASHgroups@yahoo.com> wrote in message
news:ajktj.15795$fB7.7027@en-nntp-06.dc1.easynews.com...

Hi Brad,

"Brad Velander" <bveland@SpamThis.com> wrote in message
news:vl7tj.40353$Ly.26140@pd7urf1no...
Your points are valid but I think it is far exceeding the OP
needs/knowledge. Would you really think that he is going to do even a
quarter of all that?

I expect the O.P. actually would make great use of fast & easy gate/pin
swapping if available in the program he's using, and there's a decent
chance he'd set up at least a few rudimentary net classes ("Power" &
"Signal" are always favorites), but other than that, no, he won't likely
be using many of those high-end features. My post was more just to
provide some of the "bigger picture" for his own edification.

(My experience with gate/pin swapping is that pretty much everyone does it
if the layout program has the knowledge of the various legal swaps -- or
has a feature to try to optimize the rat's nest by automatically
performing these swaps, as Pulsonix and some other programs can -- whereas
if you have to manually tell the layout package "swap pin 2 and 3" or
"swap pins 1, 2, and 3 with 7, 6, and 5" a lot of people won't bother
since it's more effort than just making a slightly "messy" route instead.)

---Joel

 

[Joel Koltner]

Hi Brad,

"Brad Velander" <bveland@SpamThis.com> wrote in message
news:vl7tj.40353$Ly.26140@pd7urf1no...

Your points are valid but I think it is far exceeding the OP
needs/knowledge. Would you really think that he is going to do even a
quarter of all that?

I expect the O.P. actually would make great use of fast & easy gate/pin
swapping if available in the program he's using, and there's a decent chance
he'd set up at least a few rudimentary net classes ("Power" & "Signal" are
always favorites), but other than that, no, he won't likely be using many of
those high-end features. My post was more just to provide some of the "bigger
picture" for his own edification.

(My experience with gate/pin swapping is that pretty much everyone does it if
the layout program has the knowledge of the various legal swaps -- or has a
feature to try to optimize the rat's nest by automatically performing these
swaps, as Pulsonix and some other programs can -- whereas if you have to
manually tell the layout package "swap pin 2 and 3" or "swap pins 1, 2, and 3
with 7, 6, and 5" a lot of people won't bother since it's more effort than
just making a slightly "messy" route instead.)

---Joel

 

[Dirk Bruere at NeoPax]

Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.

Dirk

 

[FrankW]

The cheapest and best for the layout guy
would be a pencil and a piece of paper (napkin even)

Dirk Bruere at NeoPax wrote:

Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.

Dirk

 

[DJ Delorie]

Dirk Bruere at NeoPax <dirk.bruere@gmail.com> writes:

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly

Do you need a PADS schematic, or just a PADS netlist?

gschem has a PADS netlister if you just need a netlist, and gschem
(part of gEDA) is free (beer-wise and speech-wise). (and no, it won't
force you to distribute your schematics)

http://www.geda.seul.org/

 

[Dirk Bruere at NeoPax]

On 12 Feb, 15:38, FrankW <fw...@norpak.ca> wrote:

The cheapest and best for the layout guy
would be a pencil and a piece of paper (napkin even)

Dirk Bruere at NeoPax wrote:

Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.

Dirk

Not at $60 and hour it wouldn't, since I would already have done the
work.
Can I have some sensible answers please.

Dirk

 

[Dirk Bruere at NeoPax]

On 12 Feb, 15:59, DJ Delorie <d...@delorie.com> wrote:

Dirk Bruere at NeoPax <dirk.bru...@gmail.com> writes:

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly

Do you need a PADS schematic, or just a PADS netlist?

gschem has a PADS netlister if you just need a netlist, and gschem
(part of gEDA) is free (beer-wise and speech-wise). (and no, it won't
force you to distribute your schematics)

http://www.geda.seul.org/

Thanks
Not sure which one I need - I'll have to talk with the layout guy.
However, it's got to be Windows. That's all we have here. I've tried
using Linux in the past but its a real pain.

Dirk

 

[DJ Delorie]

Dirk Bruere at NeoPax <dirk.bruere@gmail.com> writes:

However, it's got to be Windows. That's all we have here. I've tried
using Linux in the past but its a real pain.

So use gschem under windows.

 

[Christopher Ott]

"Dirk Bruere at NeoPax" <dirk.bruere@gmail.com> wrote in message
news:0d34410a-09ca-43d4-8b3e-63aef72cacec@z17g2000hsg.googlegroups.com...

On 12 Feb, 15:38, FrankW <fw...@norpak.ca> wrote:
The cheapest and best for the layout guy
would be a pencil and a piece of paper (napkin even)

Dirk Bruere at NeoPax wrote:

Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.

Dirk

Not at $60 and hour it wouldn't, since I would already have done the
work.
Can I have some sensible answers please.

Dirk

I've not used PADS, but have used Protel almost daily for the last 8 years,
and OrCAD before that. If PADS works in a similar fashion, then you won't
really be helping.

I've also had people generate schematics for me in Protel thinking they were
saving me time. It doesn't. Not unless you have my libraries. Regardless of
how pretty the schematic is, I will always have to completely redraw it to
work with my existing libraries which are usually not drawn is the same way
as the client would have. Since the library part defines the footprint it'll
always need redone. Incidentally, I can import schematics from several other
CAD packages, but would never use it for anything other than a template to
help redraw the schematic. Imported schematics never seem to work in the
same way as a natively drawn one.

Seriously, just give him what you have and let him do his part without the
constraints of a crappy imported schematic.

Chris

 

[Brad Velander]

Dirk,
There is a lot of truth in what Chris says.
If you do it, nothing says that your schematic symbols will match up
properly with the designer's footprint library. When there is a error, who's
fault is it? So the designer either has you sign-off with a warning of his
fears and the unknown nature of the interface between the two realms
(schematic/pcb), or the designer has to trouble shoot and delve into each
and every part in your schematic to make sure there are no hidden gotchas
hiding just below the surface.

--
Sincerely,
Brad Velander.

"Christopher Ott" <chrisott at ottelectronics dot com> wrote in message
news:5qednY9aK9ZpaCzanZ2dnUVZ_quhnZ2d@giganews.com...

I've not used PADS, but have used Protel almost daily for the last 8
years, and OrCAD before that. If PADS works in a similar fashion, then you
won't really be helping.

I've also had people generate schematics for me in Protel thinking they
were saving me time. It doesn't. Not unless you have my libraries.
Regardless of how pretty the schematic is, I will always have to
completely redraw it to work with my existing libraries which are usually
not drawn is the same way as the client would have. Since the library part
defines the footprint it'll always need redone. Incidentally, I can import
schematics from several other CAD packages, but would never use it for
anything other than a template to help redraw the schematic. Imported
schematics never seem to work in the same way as a natively drawn one.

Seriously, just give him what you have and let him do his part without the
constraints of a crappy imported schematic.

Chris

 

[Paul Burke]

Dirk Bruere at NeoPax wrote:

Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.

You really need the schematic program that he's using, along with the
libraries. Otherwise the components almost certainly won't match up, and
he'll have to spend a lot of time converting them. It's a real pest that
there's practically zero interoperability between different CADs, and
one place where a European directive would be useful, if they could be
trusted not to screw it up.

 

[Robert Lacoste]

"Dirk Bruere at NeoPax" <dirk.bruere@gmail.com> a écrit dans le message de
news: 48ec83a6-ef52-4886-add2-68ca79b62dd6@q77g2000hsh.googlegroups.com...

Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.

Dirk

It's not free but it's not expensive : we currently use Labcenter's proteus
suite (www.labcenter.co.uk) for schematics and simulation, and then export
the netlist in a standard Tango format when we don't to the routing
ourselves under Proteus. Our industrial partner has no problem to import
them in PADS but as someone said they have then to manually remap each
component to the corresponding footprint in PADS libraries.

Hopes that helps,
Robert
www.alciom.com

 

[Brad Velander]

Paul,
I wouldn't concur with your statement of needing the same program. For
many years I used OrCAD schematic with PADs, then Protel for Windows
replaced the OrCAD, still with PADs. Many years ago I used OrCAD with
Maxi-PC. You do need a progam that will export a simple compatible netlist
of one form or another. The more critical part is the synergy between the
schematic symbols and the PCB footprints. That synergy is buitl itno the
symbols simply by exchange of information and the standards used for pin
numbering on any devices not already covered by an accepted standard. (i.e.
SOT-23s, DPaks, SOT-223s, etc. The parts where some pin numberings differ.)
For the OP to learn the package he obtains, apply all the standards
correctly, get matching symbols and a compatible netlost output would be a
tall order. Not impossible but surely a lot slower and riskier process than
just having the PCB designer do it. The PCB designer is undoubtedly familiar
with his own tools bringing much more sped and value to the process.

--
Sincerely,
Brad Velander.

"Paul Burke" <paul@scazon.com> wrote in message
news:61flubF1v425sU1@mid.individual.net...

Dirk Bruere at NeoPax wrote:
Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.


You really need the schematic program that he's using, along with the
libraries. Otherwise the components almost certainly won't match up, and
he'll have to spend a lot of time converting them. It's a real pest that
there's practically zero interoperability between different CADs, and one
place where a European directive would be useful, if they could be trusted
not to screw it up.

 

[RESO / Claude GUTH]

http://www.lis.inpg.fr/realise_au_lis/kicad/


"Dirk Bruere at NeoPax" <dirk.bruere@gmail.com> a écrit dans le message de
news: 48ec83a6-ef52-4886-add2-68ca79b62dd6@q77g2000hsh.googlegroups.com...

Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.

Dirk

 

[Joel Koltner]

Hi Brad,

"Brad Velander" <bveland@SpamThis.com> wrote in message
news:fnPsj.43674$FA.8801@pd7urf2no...

I wouldn't concur with your statement of needing the same program. For
many years I used OrCAD schematic with PADs...

OrCAD/PADS seems to be a popular combination, at least on the west coast here.

Let me add to your informative post: While it certainly is viable to use a
different schematic capture and PCB package, what you normally lose includes:

-- The ability to "trivially" (quickly) swap equivalent gates within a package
or equivalent pins within a gate. Most PCB/schematic capture packages can do
this with "is/was" files *and the PCB guy having knowledge of what the
allowable swaps are* (this information is in the schematic library files but
not a PCB netlist), but this makes it somewhat klunkier (slower) to get done.

-- The ability to apply various layout rules based on net class. E.g., your
have your clock net class, your differential pair net class, your power net
class, etc. and the PCB package automatically sets the right defaults (clocks
might need to be routed point to point rather than in a home-run topology,
power nets are far, diff. traces have matched lengths, etc.) This can
sometimes be overcome with 3rd-party software -- for OrCAD/PADS Prescience
(http://www.precience.com/pages/PCBNavigator.asp) seems to be the well-known,
get-out-your-checkbook-and-weep solution. For small designs going around and
defining a bunch of net classes usually isn't that big of a deal since the PCB
guy can just go around and do the same thing in his tool... for big designs
schematic capture and PCB layout are potentially far enough removed that you'd
really prefer to have the schematic "drive" the layout with such rules.

---Joel

 

[Anton Erasmus]

On Thu, 14 Feb 2008 04:23:39 GMT, "Brad Velander"
<bveland@SpamThis.com> wrote:
[Fixed top posting]

"Paul Burke" <paul@scazon.com> wrote in message
news:61flubF1v425sU1@mid.individual.net...
Dirk Bruere at NeoPax wrote:
Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.


You really need the schematic program that he's using, along with the
libraries. Otherwise the components almost certainly won't match up, and
he'll have to spend a lot of time converting them. It's a real pest that
there's practically zero interoperability between different CADs, and one
place where a European directive would be useful, if they could be trusted
not to screw it up.

Paul,
I wouldn't concur with your statement of needing the same program. For
many years I used OrCAD schematic with PADs, then Protel for Windows
replaced the OrCAD, still with PADs. Many years ago I used OrCAD with
Maxi-PC. You do need a progam that will export a simple compatible netlist
of one form or another. The more critical part is the synergy between the
schematic symbols and the PCB footprints. That synergy is buitl itno the
symbols simply by exchange of information and the standards used for pin
numbering on any devices not already covered by an accepted standard. (i.e.
SOT-23s, DPaks, SOT-223s, etc. The parts where some pin numberings differ.)
For the OP to learn the package he obtains, apply all the standards
correctly, get matching symbols and a compatible netlost output would be a
tall order. Not impossible but surely a lot slower and riskier process than
just having the PCB designer do it. The PCB designer is undoubtedly familiar
with his own tools bringing much more sped and value to the process.

I agree with Brad. Most PCB packages can also export a netlist based
on the actual routed tracks. This netlist can then be compared with
the orignal netlist exported from the schematic package. If a suitable
netlist format is chosen, then it does not take too long to manually
compare the netlists and hence ensure that the PCB represents the
schematic.

Regards
Anton Erasmus

 

[Brad Velander]

Joel,
Your points are valid but I think it is far exceeding the OP
needs/knowledge. Would you really think that he is going to do even a
quarter of all that? And the PCB designer can swap gates manually and then
ink ammend the schematics if the OP does the schematics.

But addressing some of your actual comments, yes OrCAD was very popular
as a front-end for PADs. That is because back in it's day the PADs Logic was
a horrible clunky program. As a matter of fact it still is today but now
Mentor charges $1500 for it when PADs couldn't give it away free back in the
90s. Actually they did give it away free, but typically nobody would use it.

The part swapping is most dependant on the schematic packages ability to
read it back in. OrCAD could read back the PADs Was/Is file.

--
Sincerely,
Brad Velander.

"Joel Koltner" <zapwireDASHgroups@yahoo.com> wrote in message
news:vP_sj.6114$ea6.4683@en-nntp-01.dc1.easynews.com...

Hi Brad,

"Brad Velander" <bveland@SpamThis.com> wrote in message
news:fnPsj.43674$FA.8801@pd7urf2no...
I wouldn't concur with your statement of needing the same program. For
many years I used OrCAD schematic with PADs...

OrCAD/PADS seems to be a popular combination, at least on the west coast
here.

Let me add to your informative post: While it certainly is viable to use a
different schematic capture and PCB package, what you normally lose
includes:

-- The ability to "trivially" (quickly) swap equivalent gates within a
package or equivalent pins within a gate. Most PCB/schematic capture
packages can do this with "is/was" files *and the PCB guy having knowledge
of what the allowable swaps are* (this information is in the schematic
library files but not a PCB netlist), but this makes it somewhat klunkier
(slower) to get done.

-- The ability to apply various layout rules based on net class. E.g.,
your have your clock net class, your differential pair net class, your
power net class, etc. and the PCB package automatically sets the right
defaults (clocks might need to be routed point to point rather than in a
home-run topology, power nets are far, diff. traces have matched lengths,
etc.) This can sometimes be overcome with 3rd-party software -- for
OrCAD/PADS Prescience (http://www.precience.com/pages/PCBNavigator.asp)
seems to be the well-known, get-out-your-checkbook-and-weep solution. For
small designs going around and defining a bunch of net classes usually
isn't that big of a deal since the PCB guy can just go around and do the
same thing in his tool... for big designs schematic capture and PCB layout
are potentially far enough removed that you'd really prefer to have the
schematic "drive" the layout with such rules.

---Joel

 

[FrankW]

Well there ya go Dirk.
Providing a schematic from a cheap capture package
does not help the layout Person. It only invites more
chances of errors.
Cheers

Dirk Bruere at NeoPax wrote:

On 12 Feb, 15:38, FrankW <fw...@norpak.ca> wrote:

The cheapest and best for the layout guy
would be a pencil and a piece of paper (napkin even)

Dirk Bruere at NeoPax wrote:


Hi

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly
save him time compared with me drawing out the circuit in a normal CAD
package. Pin count around 1000 at present.

Dirk


Not at $60 and hour it wouldn't, since I would already have done the
work.
Can I have some sensible answers please.

Dirk

 

Dirk Bruere at NeoPax <dirk.bruere@gmail.com> wrote:

On 12 Feb, 15:59, DJ Delorie <d...@delorie.com> wrote:
Dirk Bruere at NeoPax <dirk.bru...@gmail.com> writes:

I'm looking for a cheap (or free!) schematic capture package that can
output in PADS format. I'm not the layout guy but it will certainly

Do you need a PADS schematic, or just a PADS netlist?

gschem has a PADS netlister if you just need a netlist, and gschem
(part of gEDA) is free (beer-wise and speech-wise). (and no, it won't
force you to distribute your schematics)

http://www.geda.seul.org/

Thanks
Not sure which one I need - I'll have to talk with the layout guy.
However, it's got to be Windows. That's all we have here. I've tried
using Linux in the past but its a real pain.

Try www.FreeBSD.org then

Anyway both KiCad and gEDA/gschem is available in both win32 & Linux