Homebrew_PCBs

Hi list,

Is anyone using Eagle to draw schematics and design a PCB? I just got
started with Eagle, and while I had enough experience with Orcad
Capture drawing schematics to get the schematic drawn, and the board
arranged, I'm not doing very well in creating or editing library parts.

One of my problems is the PWR labeling for the PIC18F2520 that I want
to use. It uses VDD and VSS for power, while the remainder of the
parts (EEPROM, MAX232 and some 74HCT595 gates) all use VCC and GND.
Now I don't care what you call 'em, but apparently Eagle does. It
dislikes connecting them together, and won't route them automatically
(well, not very well). And because of that, caps that I place near
the appropriate power pins of the packages don't get seen and
connected properly... At least that's what I think is happening.

I've actually spent considerable time in the manual and tutorial.
I've tried making a simple 8 resistor, 16 pin package, and although I
got through it, it looks terrible on the schematic (I know, try
again). If I could just copy one from the Bourns library, and change
the package out to a DIP, I'd have it. But although there is a way to
copy an existing library entry, I haven't figured it out. I couldn't
seem to edit existing parts either.

Can anyone help?

Alan KM6VV
P.S Project is a PIC version of Michael Dvorsky's SSC32 servo
controller (March 2006 "Circuit Cellar", pg 80).

Alan,

The copy/paste functions are part of the "magic" of Eagle. :)

Actually, they sort of suck sometimes. I've modified library devices
many times, and still can't remember the exact procedure I use to get
a variant created and ready for edits,etc. I sort of fumble through it
each time. I'm guessing here, but it was maybe something like
selecting an available item in the device/package list, and putting a
"new" name in the text entry box, then clicking OK,add,new, or
whatever they've got, and I think it may ask if you wish to create the
new item. I also think I may have had to do it separately for the
individual lib. elements (package,symbol,device?), giving them each
the new name. (sorry no Eagle on this machine here)

Unless you already know this, the copy weirdness is usually a matter
of using the group command to lasso everything you want, changing to
the *cut* tool, and then "right" clicking (I think) somewhere in the
group. Nothing will appear to happen, but you'll then have a clipboard
full of junk you can paste into a new item.

Mine are usually more like what I guess you're doing, where I want to
keep most of what they've got and put a close variant in the same
library. My changes, however, are often in footprint or package
tweaks, rather than pinnings.

Hopefully someone here knows more specifics,

George

PS- LOTS of times, I'll go for DIP packages and blank IC's, rather
than trying to create a permanent library item, but it's usually when
I'm working from the board, and don't care about the schematic.

--- In Homebrew_PCBs@yahoogroups.com, "km6vv" <KM6VV@...> wrote:

>
> Hi list,
>
> Is anyone using Eagle to draw schematics and design a PCB? I just got
> started with Eagle, and while I had enough experience with Orcad
> Capture drawing schematics to get the schematic drawn, and the board
> arranged, I'm not doing very well in creating or editing library

parts.

>
> One of my problems is the PWR labeling for the PIC18F2520 that I want
> to use. It uses VDD and VSS for power, while the remainder of the
> parts (EEPROM, MAX232 and some 74HCT595 gates) all use VCC and GND.
> Now I don't care what you call 'em, but apparently Eagle does. It
> dislikes connecting them together, and won't route them automatically
> (well, not very well). And because of that, caps that I place near
> the appropriate power pins of the packages don't get seen and
> connected properly... At least that's what I think is happening.
>
> I've actually spent considerable time in the manual and tutorial.
> I've tried making a simple 8 resistor, 16 pin package, and although I
> got through it, it looks terrible on the schematic (I know, try
> again). If I could just copy one from the Bourns library, and change
> the package out to a DIP, I'd have it. But although there is a way to
> copy an existing library entry, I haven't figured it out. I couldn't
> seem to edit existing parts either.
>
> Can anyone help?
>
> Alan KM6VV
> P.S Project is a PIC version of Michael Dvorsky's SSC32 servo
> controller (March 2006 "Circuit Cellar", pg 80).
>

Hi Alan,

I just stumbled through my first two schematics and boards with Eagle
freeware. I am a newbie and cannot offer you advice on integrating
the PIC into your schematic, as my first two circuits were just
passives and transistors. Haven't yet modified a library or created a
new part. I haven't even made my first board yet.

However, there are some good notes on making pads/streamlining
libraries at 12675. When I get a chance, I will consolidate the
other Eagle Howto's into a file for easier access. I know I will
need access to this information too!

Just wanted to say welcome. Like you, my only previous experience
with CAD was OrCAD schematic capture & board layout. If you're
patient, you'll get help from other posters. At least, that's been my
experience.

Alan N3JIY

Hi George,

Thanks for the tips! I did note that the copy/paste was NOT "windows
standard". I didn't know what to expect with CUT. After reading your post
(and the manual AGAIN), I've since made it through one variation of a part.
I wasn't clicking on the origin with the CUT.

The copy/paste (cut/paste?) was not very intuitive, that's for sure. I
think after a few more times I'll have their way down.

True, I really don't need to change much of a part, but these VCC vs. VDD
conflicts were killing me.

I already had a lovely schematic drawn in Orcad Capture. I've sense read
that I may be able to import a net list (undoubtedly modified for Eagle)
into the layout. That should be interesting.

I gather that I SHOULDN'T try to route or auto-route until the schematic is
finished and the "Electrical Rule Check" finds no errors. I can rip-up
segments of traces, but not the entire design, apparently.

Sounds like some very interesting things can be done with scripts and ULP's.
Now if I could get Orcad to import something (EDIF and PDIF, whatever THEY
are)!

I just bought the lowest level of Eagle, with the same functionality as the
free Light version. My project just fits. I'm considering going to the
next level, but I'd like to do it gradually, one "package" at a time. Does
that work? Does it make sense?

Alan KM6VV

> Alan,
>
> The copy/paste functions are part of the "magic" of Eagle. :)
>
> Actually, they sort of suck sometimes. I've modified library devices
> many times, and still can't remember the exact procedure I use to get
> a variant created and ready for edits,etc. I sort of fumble through it
> each time. I'm guessing here, but it was maybe something like
> selecting an available item in the device/package list, and putting a
> "new" name in the text entry box, then clicking OK,add,new, or
> whatever they've got, and I think it may ask if you wish to create the
> new item. I also think I may have had to do it separately for the
> individual lib. elements (package,symbol,device?), giving them each
> the new name. (sorry no Eagle on this machine here)
>
> Unless you already know this, the copy weirdness is usually a matter
> of using the group command to lasso everything you want, changing to
> the *cut* tool, and then "right" clicking (I think) somewhere in the
> group. Nothing will appear to happen, but you'll then have a clipboard
> full of junk you can paste into a new item.
>
> Mine are usually more like what I guess you're doing, where I want to
> keep most of what they've got and put a close variant in the same
> library. My changes, however, are often in footprint or package
> tweaks, rather than pinnings.
>
> Hopefully someone here knows more specifics,
>
> George
>
> PS- LOTS of times, I'll go for DIP packages and blank IC's, rather
> than trying to create a permanent library item, but it's usually when
> I'm working from the board, and don't care about the schematic.
>
>

HI Alan,

Good to meet you! I'm getting there. With some kind help from another list
member, I've been able to alter one part by making a "related" part of my
own.

I'll check out the messages on or around 12675. Consolidation would be
great! I did initially check out Eagle's News Group, but I'm not familiar
with news group operation. Then I remembered that Homebrew PCB's was
around. I was interested in it in 2001, and had joined then. Too many
lists!

I want to MILL traces with a CNC'd Sherline mill. May even get around to
finishing up a PCB router I have been collecting parts for.

I hadn't laid out a board MYSELF before, although I've seen plenty of them
developed. The auto-router is really NEAT!

Alan KM6VV

>
> Hi Alan,
>
> I just stumbled through my first two schematics and boards with Eagle
> freeware. I am a newbie and cannot offer you advice on integrating
> the PIC into your schematic, as my first two circuits were just
> passives and transistors. Haven't yet modified a library or created a
> new part. I haven't even made my first board yet.
>
> However, there are some good notes on making pads/streamlining
> libraries at 12675. When I get a chance, I will consolidate the
> other Eagle Howto's into a file for easier access. I know I will
> need access to this information too!
>
> Just wanted to say welcome. Like you, my only previous experience
> with CAD was OrCAD schematic capture & board layout. If you're
> patient, you'll get help from other posters. At least, that's been my
> experience.
>
> Alan N3JIY
>