Can't resolve implicit power pin conflicts.

Question

How do I resolve the problem with implicit power pins not being allowed to co exist. When different ICs on the same project have differing power/GND names. ie. GND and V- etc.Eagle will allow only one name when connecting the signals.I have read many discussions with some indicating that it can be turned off. Can someone please help? I am sure it must be simple but I have not been able to solve.

Thanks.

Bill

dukepro · Accepted Answer

On 03/15/2014 11:06 PM, billpenner wrote: How do I resolve the problem with implicit power pins not being allowed to co exist. When different ICs on the same project have differing power/GND names. ie. GND and V- etc.Eagle will allow only one name when connecting the signals.I have read many discussions with some indicating that it can be turned off. Can someone please help? I am sure it must be simple but I have not been able to solve. Thanks. Bill Good morning, Bill, Search this forum for a thread titled "Power and Supply Pin Use on Schematics" originally posted on 30-Sep-2013 by David Kanazawa. On 01-Oct-2013, I posted a rather lengthy response that included shorts.lbr and how to use them, along with a screen shot of their use. The following day, I posted an even lengthier commentary on why one should or should not use shorts. David found my responses as well as those of others very helpful. I believe that you'll find the referenced thread will answer the "how" and "why" of your question. Enjoy, - Chuck

shabaz · Answer

Hi Bill, I think EAGLE doesn't care what the pin is named, just cares what the net is named. So, usually I just connect the pins as desired, and make sure the ground net is labelled something appropriate (e.g. 0V), supply is labelled 3V3 or similar, etc. EAGLE won't care if I connect 3V3 to VDD pins or VCC, etc. As I understand, there is no way to give a net two names without a component in-between (e.g. a star ground point), which is really then two nets anyway. Sometimes I do want to give a different name for information purposes near a connector for example, but in that case I work around it by just making a text note on the schematic (e.g. something like "Vin" or "Supply_out" even if they are connected to the same net).

autodeskguest · Answer

On 16/03/14 03:34, shabaz wrote: I think EAGLE doesn't care what the pin is named, just cares what the net is named. So, usually I just connect the pins as desired, and make sure the ground net is labelled something appropriate (e.g. 0V), supply is labelled 3V3 or similar, etc. EAGLE won't care if I connect 3V3 to VDD pins or VCC, etc. I don't think that's quite true. If the power pin is named "VDD" and you connect it to a net called "3V3" then you get a warning in the ERC, but the connections are made correctly as you intend. If a component has a (hidden) pin marked as direction "power" and named "VDD", and if you have a net named "VDD" (with a supply symbol on it), and you leave that power pin uninvoked, then Eagle will automatically connect it to the net. This behaviour is convenient if all your components have the same power supply naming convention, but can be overridden with explicit connections if not.