invisible power pins on shematic

rickford66 wrote:

Hi,

Getting up to speed on Eagle. Almost done with my first design. Have

a question about power pins. On logic gates and such, the power pins

are "invisible". In order to connect them to the power and ground I

desire, the only way I've found to do it is to bring the power pins

into the schematic and connect them to the corresponding power and

ground. This leaves the pins visible on the schematic. Doesn't that

conflict with the idea that power pins are invisible? On my old DOS

program, I made the pins visible, changed their attributes so they

would connect to the appropriate net, then made them invisible again.

Can this be done in Eagle? Thanks.

Long story short. No.

If you organise your libraries to have pin names that match the power rail

names then the connections are automatic.

If the logic libraries have a VCC pin then provide a VCC power supply. In

this way  the power pins will connect automatically. If necessary give it a

explanatory +5v label.

If your libraries have a mix of power supply pin names then you will always

have to manage the result.

Power pins are not invisible in many instances. Often they are depicted in

an area of the schematic with their associated decoupling capacitor.

Warren

--

Viewed / responded via the newsgroup at

news.cadsoft.de

Ok, thanks.

Il 02/02/2012 21:33, Warren Brayshaw ha scritto:

Long story short. No.

If you organise your libraries to have pin names that match the power rail

names then the connections are automatic.

If the logic libraries have a VCC pin then provide a VCC power supply. In

this way  the power pins will connect automatically. If necessary give it a

explanatory +5v label.

If your libraries have a mix of power supply pin names then you will always

have to manage the result.

Power pins are not invisible in many instances. Often they are depicted in

an area of the schematic with their associated decoupling capacitor.

I would add that the invisible pins should be avoided because it is very

useful to know which pin is connected to the power supply, for debugging

and test purposes.

Marco

On Thu, 02 Feb 2012 18:57:46 +0000, rickford66 wrote:

Hi,

Getting up to speed on Eagle.  Almost done with my first design.  Have a

question about power pins.  On logic gates and such, the power pins are

"invisible".  In order to connect them to the power and ground I desire,

the only way I've found to do it is to bring the power pins into the

schematic and connect them to the corresponding power and ground.  This

leaves the pins visible on the schematic.  Doesn't that conflict with

the idea that power pins are invisible? On my old DOS program, I made

the pins visible, changed their attributes so they would connect to the

appropriate net, then made them invisible again.  Can this be done in

Eagle? Thanks.

Just an editorial comment:

Over the years that I've been doing circuit design, I've developed a

severe dislike for power pins that automagically connect up to specific

nets.  First, because you have to have the right net names, and tools

generally don't like you doing things like connecting "VCC" to "VDD". 

Second, because as soon as you have more than one power net (e.g. a 3.3V

digital and a 3.3V analog, or a 5V and a 3.3V VDD line, or a "regular" VDD

and a "battery standby" VDD, etc.), then you need visible pins anyway. 

Third, because you're never quite sure what net your power pins are

supposed to be connected to, and so you have to do all this laborious

checking.

I, personally, and none of the engineering groups that I have worked in,

have ever tolerated, much less preferred, the practices of hidden,

automagically connecting, power pins.

--

My liberal friends think I'm a conservative kook.

My conservative friends think I'm a liberal kook.

Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software

http://www.wescottdesign.com

I preferr visible pins too, but I don't want to re-do all the logic libraries.  When I design my own parts, they always have visible pins.

I thought it was just me being "behind the times" at my advanced age (61),

glad to see others are not thrilled with "automagic pins" either.  Too bad

there is not some option check box somewhere that says "show all hidden

pins" or something.  I have always found that "intuitively obvious" will

bite you !! 

mikey

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

Il 07/02/2012 15:27, rickford66 ha scritto:

I preferr visible pins too, but I don't want to re-do all the logic libraries.  When I design my own parts, they always have visible pins.

There's no need to change the libraries. Just invoke the power pins in

the schematic.

Marco