How best to handle multiple connectors with the same signal?

Making PCB Layouts, Manual routing, Auto-routing, Copper pouring, Updating from Schematic, Manufacturing Output
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KurtEck
Posts: 18
Joined: 15 May 2011, 12:55

How best to handle multiple connectors with the same signal?

#1 Post by KurtEck » 05 Mar 2012, 10:36

Sorry if this has been answered before, I did not find it with my searches.

Suppose you are designing a board, in this case an Arduino Mega Shield, that has several connectors that plug into the actual Arduino Mega. There are several signals (Gnd, +5V, RST, ...) that are on more than one pin on these connectors. So the question is. Is there a way to say, that there are 6 GND pins that are coming in to the board and when I need a GND signal on the board, I can route to any of them and that I don't necessarily have to route between them.

I am sorry if the answer is obvious. My guesses that I will probably try, include using Jumpers? or maybe see if there is some form of Pin class that says that the pins are already connected...

Thanks again
Kurt

lindquist
Posts: 45
Joined: 22 Oct 2011, 17:58

Re: How best to handle multiple connectors with the same sig

#2 Post by lindquist » 05 Mar 2012, 10:59

I could use a solution for this as well!

mclemens1969
Posts: 12
Joined: 28 Jan 2012, 17:42

Re: How best to handle multiple connectors with the same sig

#3 Post by mclemens1969 » 09 Mar 2012, 14:54

When you specify the component for your connectors, you could specify only the ones you are interested in using as being ground.

KurtEck
Posts: 18
Joined: 15 May 2011, 12:55

Re: How best to handle multiple connectors with the same sig

#4 Post by KurtEck » 10 Mar 2012, 09:44

Thanks, I understand that, which works fine, except diptrace will want to place etch between each of these pins I specify. What I was wondering if there was some way to say that these pins are already connected externally. So far I have not found this,but worked around it on my current design.

The options I know I could choose:
a) Punt(which I did) - Run the etch between all of the GND pins...
b) Create multiple circuits like: GND-TOP, GND-Bottom, GND-???, and me choosing potentially arbitrarily in the schematic which gnd pins go with which of these circuits.

I was just hoping I missed something obvious...
Kurt

Alex
Technical Support
Posts: 3131
Joined: 14 Jun 2010, 06:43

Re: How best to handle multiple connectors with the same sig

#5 Post by Alex » 12 Mar 2012, 08:55

Software doesn't know where you will plug a board in. Therefore it can't know that some pins already connected on other board.

Suppose you have a connector that has multiple ground pins. When you create a schematic connect single pin only to ground net. That will propagate to board file if you renew layout from schematic.

KurtEck
Posts: 18
Joined: 15 May 2011, 12:55

Re: How best to handle multiple connectors with the same sig

#6 Post by KurtEck » 12 Mar 2012, 09:42

Thanks Alex. I understand that you don't want to do it in a general way as the vast majority of the time you need to route all of the pins of a circuit... As I mentioned in the previous post, I already finished that board and am about to get a few fabricated. I was just wondering (hoping for future cases), that there may be a way for me to tell the software that these N pins are already connected. Maybe using the concept of off board jumpers...

In this case it may be a good thing anyway that I did not assume there was enough trace width on the main board (Arduino Mega, Chipkit Max32...) connecting the grounds, to handle the current of the servos....

Kurt

Fenichel
Posts: 48
Joined: 10 Mar 2012, 17:23

Re: How best to handle multiple connectors with the same sig

#7 Post by Fenichel » 12 Mar 2012, 20:55

I haven't tried this yet, but it might be possible to design an n-layer board in n+1 layers. The n+1st layer would be pro forma, never to be Gerberized and submitted to the PCB fab, but appearing to make all the interconnects that are actually being made externally. I wouldn't be surprised to hear of some hidden gotcha in this approach, but it might solve KurtEck's problem.

KurtEck
Posts: 18
Joined: 15 May 2011, 12:55

Re: How best to handle multiple connectors with the same sig

#8 Post by KurtEck » 05 May 2016, 18:12

Was wondering if any of the improvements with the current versions of diptrace have improved this?

Example: Suppose I am designing a new HAT for RPI2 (or Odroid C2 or UP board), and I need to connect my boards ground up to the connector associated with the RPI expansion connector.

In this case I have many choices including (6, 9, 14, 20, 25... 39). So the question is if I tell diptrace that all of these pins are GND, it will want my board to have a connection to every one of them.

It would be nice to instead say they are somehow jumper-ed together, so I can then choose how many of them I wish to physically connect to...

Thanks again

Kurt

AyalaResearch
Posts: 2
Joined: 26 May 2016, 15:51

Re: How best to handle multiple connectors with the same signal?

#9 Post by AyalaResearch » 03 Sep 2019, 16:56

It's nice to see I am not the only person with this issue. I have a board that will act like an Arduino shield connecting to an Arduino Mega. Additionally, I have 6 Pololu Motor drivers which have 4 connected ground pins, 3 are low current, but the 4th can pull over 5 amps. I've had to add a number of addition traces connecting between isolated copper pour areas to tie them to ground as well as tie the extra ground pins to ground as needed. The "compare to schematic" operation makes for a large number of differences between schematic and layout.

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