Component layout on PCB's

[Zero999]

We used to use A!tium where I used to work.

Eagle makes me swear but I know lots of companies use it, so after being unemployed for nearly a year I've decided to teach myself how to use it so I can add it to my CV. I've finally  got to doing the PCB, after having to partly redraw the schematic because I didn't realise that they both files had to be open simultaneously to update which A!tium does perfectly regardless of whether all the files are open or not.

I know what you mean, using Eagle just makes me long for A!tium which I don't have at home. Now I've nearly done the PCB but I'm having problems with not being able to connect some of the components because the pads are off grid which is unacceptable because I'm using the default grid and libraries which should use the same grid, or at least a compatible one and this shouldn't be a problem anyway because it should be possible to work off-grid.

Eagle's 'help' file is a joke and makes the documentation provided with most open source software look world class. Nevertheless I'm going to persevere with Eagle for now because it will look good on my CV and hopefully an employer will be impressed that I had the patience to learn it.

EDIT:
I've finished the PCB. I didn't know how to put pads in so I used vias, which I hope will be fine. I don't like the way half of the text is vertical and half is horizontal and there doesn't seem to be a way to move the text separately.

I got round the grid problem by changing the components to ones that use a 0.05" grid, which involved going back to the schematic and replacing the transistors and the capacitors, what a pain?

Next I'll try a circuit with logic gates or a quad op-amp to see how well/poorly it handles swapping pins or gates/op-amps so it fits nicely on the board. Don't worry, I'll start a new thread - I've derailed this one enough.

[RayJones]

Your PCB design looks good, and is a classic follow the schematic approach (nothing wrong with that).

Not so sure though about the extra details in the component overlay, eg bumps on resistors, swirls in LEDs, cap symbol with small +. 
Best cap overlay I've seen is where they have about 30-40% shaded on the negative side (ala the stripe on the cap) Failing that a prominent + is good too.

I still use Protel99SE, and it too is a perpetual battle getting schematic descripitions to align with the PCB footprints.
Perhaps the newer versions are better and allow you to design the schematic symbol AND the PCB footprint in one place.....

One especially frustrating aspect is you place a NPN from the standard schematic library, and associate it with a TO-92A in the standard PCB library (or even TO-220)
When you place the matching PCB footprint, the pads are numbered 1, 2, 3 BUT the schematic is (more logically) numbered B, C, E. Arrrggggh 

[RayJones]

Argghhh - just been caught again with Protel.

A standard diode in the schematic uses pins 1,2.  PCB uses A,K - the exact opposite of my earlier transistor example 

[TheDirty]

EDIT:
Eagle has just told me that my schematic is wrong because there are missing net junctions, which I've found out are those little dots where wires join, which every other schematic editing program I know of places automatically! WTF?

It puts them down for me.  I have no idea how you were able to draw that schematic with incorrect connections.

I know what you mean, using Eagle just makes me long for A!tium which I don't have at home. Now I've nearly done the PCB but I'm having problems with not being able to connect some of the components because the pads are off grid which is unacceptable because I'm using the default grid and libraries which should use the same grid, or at least a compatible one and this shouldn't be a problem anyway because it should be possible to work off-grid.

If you start the trace from the off grid pad it will centre properly.

I don't like the way half of the text is vertical and half is horizontal and there doesn't seem to be a way to move the text separately.

You use the 'Smash' tool to break the item into it's components and you can move the labels around how you want.

[charliex]

for pad's i just add pad in the schematic, with a library of pad parts. i don't know if theres a better way.

the off grid junction thing i came across a couple of days ago myself when i edited someone elses schematic, it wouldn't place a junction or connect the wires since the grids were off. So this is just a matter of standardisng the grid before anything is created,  the default grid i find is too coarse.

you can write a script that will realign the packages to the grid, which is useful for this sort of thing, there's probably something already on their ftp site too.

i did find eagle fairly intuitive to pick up, but then i like the scripting and command line aspect of it, so i think its just what you're used too. we use protel99 at work and i did find it a steeper learning curve.

Didn't really find the ui that bad, if i'm making a quick circuit i'll usually do it in eagle, you just have to learn its odd quirks, which i think they all have in some form. i think if you're used to the bigger pcb packages you'll struggle with eagle, but for the first timers it seems easier to pick up, but then you'll hit its growing curve , which is why i always recommend A!tium to newbs, but they'll balk at the cost and go with eagle, epecially since most open source hardware stuff seems to use it too.

A!tium just feels like the 600lb corporate gorilla and not as friendy an enviroment to get into, eagle gives the impression of beign a bit more 'hacker' friendly. It's that mob mentality, you see other people using it, so you do too. I'm sure A!tium aren't strapped for customers, but I reckon it couldn't hurt them to look at this enviroment like Ti tried to do with the MSP430, but only if they can give that same feel.


its also good to use the vector font option, sparkfun have a nice introduction to setting up eagle for the first time.

[andri]

I don't like the way half of the text is vertical and half is horizontal and there doesn't seem to be a way to move the text separately.

You can use the smash command for that. This separates labels from the element and you can move them separately.

[Zero999]

Thanks didn't know about the smash command, then there's the unsmash, which does the opposite.

I suppose I can understand people finding Eagle easier to use than Altium because of the command line interface, especially if they're used to AutoCAD.

I've put-off learning Eagle or any other PCB package apart from Altium for too long. I've made plenty of PCBs at home which I drew using OpenOffice.org draw rather than a proper program. I wish I had taken the time to learn Eagle before.

I'm still finding new things, the delete function doesn't work for tracks, one has to use the ripup command which is silly.

[charliex]

delete is mostly for schematics, ripup for pcb's, i can see that it might work if delete implied rip on tracks on the board. I find the polygon processing a bit annoying, i don't want to flood fill to happen on every ratsnest, so i turn it off, but then i want it sometimes. I haven't found an easy way of doing that yet, i hope there is one, that and a proper undo/redo would be great. Can't count the number of times i've accidently run an autoroute when i was doing manual routing and it won't step back, though no doubt you can use the b?d files to do it, but seriously. I also dont like if i turn off a layer and when i'm routing it turns it back on again, especially after i explictly give it a layer command.

It'd be nice if you could add stuff in the pcb and it'd appear in the schematic the program probably has too much of a wall between the schematic and pcb to implement it. i can see it being some design choice.

ahh well, if only everything were perfect!

[Zero999]

delete is mostly for schematics, ripup for pcb's,

It often seems like Eagle is designed to confuse people.

Why not just have one delete command which works for both schematic and PCB?

I discovered the ripup command when Googling for something else, there's no other way I would've found it.

Can't count the number of times i've accidently run an autoroute when i was doing manual routing and it won't step back

That's annoying too.

Once I've learned enough Eagle to get by I think I'll write a tutorial as I've yet to see a good one. The only ones I've seen are either too long winded and packed full of superfluous information or are too brief and skip the basic things which most nubes seem to struggle with.

[TheDirty]

Because using delete applies to the net and using ripup applies to the routing.  Because it's different doesn't make it wrong.

[RayJones]

Most of my work with Protel involves simple keystrokes to do the work. eg PT = Place Track, PP = Place Pad, MD = Move Drag end, and many many more.

In a recent post Dave stated the latest Altium version also still honour these keyboard shorts cuts.

I suppose it helps if you actually started out with AutoTrax!

[Zero999]

Because using delete applies to the net and using ripup applies to the routing.  Because it's different doesn't make it wrong.

It's inconsistent which is poor UI design - all half decent GUIs use the same functions to accomplish similar tasks.

[TheDirty]

It's inconsistent which is poor UI design - all half decent GUIs use the same functions to accomplish similar tasks.

I'm sorry, but your constant complaining about these UI choices is just tiresome now.  It's not inconsistent it's a UI choice of distinguishing deleting which would apply to the net itself or ripping up, which applies to the routing.  It's logical to distinguish between the two things.

[EEVblog]

A!tium just feels like the 600lb corporate gorilla and not as friendy an enviroment to get into, eagle gives the impression of beign a bit more 'hacker' friendly. It's that mob mentality, you see other people using it, so you do too. I'm sure A!tium aren't strapped for customers, but I reckon it couldn't hurt them to look at this enviroment like Ti tried to do with the MSP430, but only if they can give that same feel.

They dropped the low end of the market a long time ago.
Not too long ago tried to reclaim it in a way with massive price reductions, but still out of the reach of the low end user.
Frustratingly for many, the "low end" product does NOT include PCB, you have to buy the full package to get basic PCB and schematic functionality.
The "low end" focus is on FPGA development.

Dave.