Pars said:
How do you name nets? Is there a way to end a net in a label (to show connection to a bus such as a clock)? Or do I have to connect each and every device on the bus using nets and showing the connection in the schematic? I'm looking to clean up a microprocessor schematic?
Bryan A. Thompson
bryan@batee.com
Just got back online, and it looks like you guys have covered all the bases. Eagle does have a steep learning curve, but it's much easier than a lot of programs that have the same functionality. However, in my experience a lot of these powerful programs have slightly different interfaces, and sometimes you need to try several before you get one that clicks with the way your mind works.
Hello SY, batee,
Generally, one should never use the wire tool for anything that does belong to a certain potential. The wire tool is for drawing general wiring that should be placed by hand, but it belongs to one and the same potential wherever you use it. That explains the wire glob when crossing muliple of them.
If you want to declare electrical routes of different potential, use a net for each such connection. The name is a little misleading, but that's just because the most simple case of connecting two component pins is a special case of the general net functionality. Nets get a default name that you can generally keep and leave alone. OTOH, you can even label a net (via the label tool) if you fell like it (as I mentioned in the bus explanation). And here shows why a net is a net and not just a wire. You can join different nets together - basically what makes multiple connections a true network. But I don't recommend this for regular signal wiring.
Spreading nets across the schematic is for distributing power, ground, clock etc., without having to draw an explicit connection between two grounds. The way Eagle does this is really that easy: different nets that you connect to, e.g., a ground become all named like the ground symbol you connect to them. Thus, connecting the very same ground symbol to some nets makes them all the same ground. The board will then reflect this by generating "air wires" across this whole net to remind you that the different parts of the net have to get an electrical connection ultimately before the board layout can be considered finished (in general, a board layout is valid when it has no rule check errors and no air wires left).
There's even a bus drawing tool just left of the net drawing tool. Basically, you can draw bus bars where you want them. You can then connect nets to the bus bar and branch them off at any other place along the bus length. Makes it easier to see a bus route by looking at it. You can then name and/or label the bus wires to suit your needs, but it is not strictly neccessary to name them beautifully...
So long,
Sebastian.
Generally, one should never use the wire tool for anything that does belong to a certain potential. The wire tool is for drawing general wiring that should be placed by hand, but it belongs to one and the same potential wherever you use it. That explains the wire glob when crossing muliple of them.
If you want to declare electrical routes of different potential, use a net for each such connection. The name is a little misleading, but that's just because the most simple case of connecting two component pins is a special case of the general net functionality. Nets get a default name that you can generally keep and leave alone. OTOH, you can even label a net (via the label tool) if you fell like it (as I mentioned in the bus explanation). And here shows why a net is a net and not just a wire. You can join different nets together - basically what makes multiple connections a true network. But I don't recommend this for regular signal wiring.
Spreading nets across the schematic is for distributing power, ground, clock etc., without having to draw an explicit connection between two grounds. The way Eagle does this is really that easy: different nets that you connect to, e.g., a ground become all named like the ground symbol you connect to them. Thus, connecting the very same ground symbol to some nets makes them all the same ground. The board will then reflect this by generating "air wires" across this whole net to remind you that the different parts of the net have to get an electrical connection ultimately before the board layout can be considered finished (in general, a board layout is valid when it has no rule check errors and no air wires left).
There's even a bus drawing tool just left of the net drawing tool. Basically, you can draw bus bars where you want them. You can then connect nets to the bus bar and branch them off at any other place along the bus length. Makes it easier to see a bus route by looking at it. You can then name and/or label the bus wires to suit your needs, but it is not strictly neccessary to name them beautifully...
So long,
Sebastian.
I am joining the party!
Having used heavyweight (ORCAD, PADS) CAD years ago but forgottem them, I am trying Eagle for the first time for DIY projects.
One basic problem is that it has the Windows pardigram the wrong way round! It should be select an object (eg Pad) then right click for a list of things to do with it. Eagle insists on selecting a function and then applying it to an object.
Autorouting on anything but dense logic layouts with strict component grids is a waste of time. For analogue, just say no.
How on earth do I pour copper and attach it to a net ???? The Help file gets one into writing scripts - great fun but I don't want to do that yet!
Keep telling myself this is FREE
Having used heavyweight (ORCAD, PADS) CAD years ago but forgottem them, I am trying Eagle for the first time for DIY projects.
One basic problem is that it has the Windows pardigram the wrong way round! It should be select an object (eg Pad) then right click for a list of things to do with it. Eagle insists on selecting a function and then applying it to an object.
Autorouting on anything but dense logic layouts with strict component grids is a waste of time. For analogue, just say no.
How on earth do I pour copper and attach it to a net ???? The Help file gets one into writing scripts - great fun but I don't want to do that yet!
Keep telling myself this is FREE
Re: I am joining the party!
Click the polygon button in the toolbar on the left side, go to the command line and type in the net name you'd like to give it, and draw the border of the copper pour in your layout. You have to end the polygon exactly where you started. Now click the Ratsnest button and it will render the copper pour. If you'd like to get rid of the pour click the Ripup button and click on the border of the pour. It won't delete the polygon it will just remove the pour.
cliff said:
Click the polygon button in the toolbar on the left side, go to the command line and type in the net name you'd like to give it, and draw the border of the copper pour in your layout. You have to end the polygon exactly where you started. Now click the Ratsnest button and it will render the copper pour. If you'd like to get rid of the pour click the Ripup button and click on the border of the pour. It won't delete the polygon it will just remove the pour.
There's another approach to this.
Draw your polygon. Press ratsnest. the polygon is created.
Darn, it doesn't connect to the net, it's applying your clearance-rules you set in your design-rules (under Edit- at the bottom)
Go to the buttons on the left, go to the most-left row. the 9th button from the top has the tag "name".click it to select this function.
Click on the net on your board to find out it's name.Dont change it.just press ok or cancel.
Click on one of the lines of the polygon you just created.
Change the existing name to the name of the net you want to connect to.
Eagle will ask you if you want to connect the signals and use a name. choose a name and confirm.
Klaas
Draw your polygon. Press ratsnest. the polygon is created.
Darn, it doesn't connect to the net, it's applying your clearance-rules you set in your design-rules (under Edit- at the bottom)
Go to the buttons on the left, go to the most-left row. the 9th button from the top has the tag "name".click it to select this function.
Click on the net on your board to find out it's name.Dont change it.just press ok or cancel.
Click on one of the lines of the polygon you just created.
Change the existing name to the name of the net you want to connect to.
Eagle will ask you if you want to connect the signals and use a name. choose a name and confirm.
Klaas
sek said:Regarding the "Windows" - Paradigm: Eagle is Unix software, ported to Linux, Windows and Mac OS.
Cheers.
Then I apologise, but for non Unix users (although I did "grep" around in past times ;-) it does start off being counter-intuitive.
I guess that means that "intuative" is what one is used to.
Exactly, because applying tools to selected objects via the contextual menu is neither a Windows (or Microsoft) invention, not is it standard.
The usual - and actually more intuitive - way in professional tools (be it audio, video, graphics, design, etc.) is: first grab a tool, then use it on an object. Just like in real life...
OTOH, Eagle doesn't implement contextual menus at all, though. Why the manufacturer Cadsoft still does that is beyond me...
S.
I think I have hijacked Sy's thread !
But while I have your attention .....
1) I am used to using a 0.1" dot grid. When I display it I still cannot place components so that a pad sits on a grid point. Some do, some don't and I cannot see the logic.
2) I can't see how to create a board outline. Obviously I can draw a line around the board, but how to get this on all layers? What about registration marks?
Now I see the Unix port and understand - most of the help refers to CLI. Pity as the basic engine is very good.
But while I have your attention .....
1) I am used to using a 0.1" dot grid. When I display it I still cannot place components so that a pad sits on a grid point. Some do, some don't and I cannot see the logic.
2) I can't see how to create a board outline. Obviously I can draw a line around the board, but how to get this on all layers? What about registration marks?
Now I see the Unix port and understand - most of the help refers to CLI. Pity as the basic engine is very good.
Re: I think I have hijacked Sy's thread !
A board outline is done with the 'dimension' layer as far as I recall. Select this layer and draw a trace around the board. It will show on all layers unless you disable viewing this layer.
cliff said:But while I have your attention .....
2) I can't see how to create a board outline. Obviously I can draw a line around the board, but how to get this on all layers? What about registration marks?
A board outline is done with the 'dimension' layer as far as I recall. Select this layer and draw a trace around the board. It will show on all layers unless you disable viewing this layer.
Re: I think I have hijacked Sy's thread !
The same thing drives me nuts for a day...than I figure it out: if a component in question was place in different grid (like 0.0125"), and you copy it, and you decide to change a grid to 0.1", chances are (8:1) that the new component will be placed in incorrect grid. Switch the grid again to 0.0125", move the component a bit until it fix to 0,1" grid.
cliff said:
The same thing drives me nuts for a day...than I figure it out: if a component in question was place in different grid (like 0.0125"), and you copy it, and you decide to change a grid to 0.1", chances are (8:1) that the new component will be placed in incorrect grid. Switch the grid again to 0.0125", move the component a bit until it fix to 0,1" grid.
Both questions have been answered (thanks ).
To add a bit: The grid is also imposed in the component library. If you happen to place a component into a grid that isn't anything like a multiple of the component grid, then the component center will match the grid and the component pins/pads won't! Changing grid after having placed components does also only work with "compatible" (e.g. multiple) grid values (smallest common denominator of any number of grid values in question).
Also, board outlines really only belong into the dimension layer, while registration marks can be placed onto each copper layer, for example. The Eagle distribution contains a couple of "scripts" to accomplish exactly this for you, namely by clicking "File" -> "Run Script" (or clicking the script tool button) and choosing, e.g., "euro.scr". This example script shows you how it can be done. I wrote my own scripts for various board size and registration mark types. You can also draw your favourite dimension outline and layer registrations into an empty board file and "Export..." it into a script file.
Cheers,
Sebastian.
).To add a bit: The grid is also imposed in the component library. If you happen to place a component into a grid that isn't anything like a multiple of the component grid, then the component center will match the grid and the component pins/pads won't! Changing grid after having placed components does also only work with "compatible" (e.g. multiple) grid values (smallest common denominator of any number of grid values in question).
Also, board outlines really only belong into the dimension layer, while registration marks can be placed onto each copper layer, for example. The Eagle distribution contains a couple of "scripts" to accomplish exactly this for you, namely by clicking "File" -> "Run Script" (or clicking the script tool button) and choosing, e.g., "euro.scr". This example script shows you how it can be done. I wrote my own scripts for various board size and registration mark types. You can also draw your favourite dimension outline and layer registrations into an empty board file and "Export..." it into a script file.
Cheers,
Sebastian.
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