Electronic – Eagle multiple pads to one pin

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I have a part in Eagle that has two pads for V_DD (pad 1 and 2) and two pads for V_BAT (pads 9 and 10). The pads must be tied together on the PCB so I have designated a single pin for each pair of pads.

With the pins set to show both the pad and pin names, I expect to see V_DD as a pin name and 1*2 for its pad name as well as V_BAT as a pin name and 9*10 for its pad name. This works fine for V_DD but not for V_BAT. For some reason, V_BAT is showing 9*2 as if it were connected to pad 9 and 2; however, that is not the case.

I am relatively new to Eagle so I'm sure its a simple mistake but I can't seem to figure it out. I have attached screenshot snippets of the relevant information.

Best Answer

There isn't actually an connection problem here, just a misunderstanding of what the names mean.

When multiple pads are connected together, their names are not all shown, but rather are labelled as:

<First Pin>*<Number of Pins>

Where the first pin is any of the pins in the group, usually the one with either the lowest number, or first when sorted alphabetically.

The number of pins indicates how many pins in total are connected together.

Essentially you can read it as "Pin x and the group of n pins".

Related Solutions

Electronic – How to connect a pin that is not included on the main symbol or any of the gates of an Eagle part

Sounds like the parts are not defined exactly as you would like them in the Eagle library. I would make new versions of the parts in the library (I don't suggest directly editing the existing ones) by copying the parts and adding the missing pins. In the case of the HTSSOP package you will also want to add the thermal pad for the layout.

There are several tutorials on the web re creating and copying parts in the Eagle library, such as this one.

Electronic – How to facilitate keeping multiple grounds, (i.e. AGND, DGND, etc…) separated in the layout when using Eagle

Create a footprint with GND and AGND pads. Draw copper between these pads. Yes, this will produce a DRC "Overlap" error as shown below:

DRC "Overlap" error in errors dialog

This is OK. There three buttons at the bottom:

Clear all
Processed
Approve

"Clear all" will temporarily clear the list for this run of the DRC. I'm not sure why that's useful; just close the window if you want it shortened.

"Processed" will fade out the color of the red X. This is potentially useful if you're iterating through a long list of DRC errors and fixing them as you go; you can keep track of the ones you think you've corrected.

"Approve" is the only one I use on a regular basis. This moves the error from the errors list to the approved list:

Error moved to approved list in errors dialog

and keeps it there on subsequent runs of the DRC. Note that this only moves this specific error with this specific pair of nets at this specific location. Closing this window and running the DRC again produces the notification "DRC: 1 approved errors"

DRC: 1 approved errors

and no "DRC Errors" dialog. You can get this dialog back by creating an error, or (preferably) the errors command, the yellow exclamation point in the above screenshot, or the menu Tools -> Errors.

The "Approve" functionality exists for a reason, the same reason that we have tools like

#pragma GCC diagnostic ignored "-Warning"

Sometimes, it's OK to ignore a DRC error. This is one of those times.

Best Answer

Related Solutions

Electronic – How to connect a pin that is not included on the main symbol or any of the gates of an Eagle part

Electronic – How to facilitate keeping multiple grounds, (i.e. AGND, DGND, etc…) separated in the layout when using Eagle

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