More Eagle PCB Questions

[soggybag]

I'm working on a project with Eagle. I'm using gaussmarkov's excellent library. Now for the question:

I wanted to add an input and an output. I noticed in the library under gm-supply there is a "part" named IN. But, it has this note:

• obsolete: use Mark instead and label net
  
• schematic input label without circuit board terminal/pad
• labels net "IN"
• provided as complement to OUT (rarely used)

I'm not sure how to use Mark and or label?

My project also uses several different supply voltages, I have a 9v, 4.5v, 5v and 2.5v, and a CV. I'd like to create a net that can represent this without having to connect all of these with a wire.

Thanks

[soggybag]

And another one! My project uses a TL074 from the library. I'd like to change this to a TL064. This is minor problem, but it would be nice if it were all correct.

While we're on the subject of the TL064. I noticed this part doesn't show Vcc and Vdd connections in the schematic view. Is it possible to add or show these, or am I just not seeing them for some reason?

[eurekaiv]

For the IN and OUT I simply add a pad from the library.  I believe in the Gauss Markov stuff pads are under the supply group.  You can select a few different shapes as well.  Use the "Name" tool in the toolbar (a resistor symbol with R2 over top) to change the name of the pad to either IN or OUT.

The GM library includes library items for VA, VB, VC, VD, and VR.  To use different supply voltages just add VA (say that's your 9V supply) wherever you want to connect to 9V and then do the same for VB and so on.

As for a TL064 the pinout is identical and so you'd simply change the IC's part value using the "Value" tool (next to the name tool).  You might get an error but it will let you change it in your schematic just fine. I have a TL064 in the GM libraries I have installed though so I'm not sure why you don't just swap it.  There's a tool to do just that right beneath the "Add" tool.

To add the power and ground supply connections you have to use the "Invoke" tool.  It's the one in the toolbar that looks like 4 schematic symbols with an arrow. Select that tool then click your part and it will open a popup with the PWR+ at the bottom of the list.  Double click that item and it will give you pin 4 and 11 to drop in your shcematic.

[soggybag]

Thanks for the reply.

Is there a way to clear a board once you've started? I started a board, but later made some changes to the schematic. Now I get errors when I go back to edit the board. It sounds like the changes to the schem may not be displayed in the board. So I thought I'd just start over again on the board.

[Andi]

Just delete the board file and it'll be recreated when you switch to board again.