Hi guys. please help. i am doing a very basic 2 push button design with a 5V supply and GND. Unfortunatly I cant upload the sch file or a pdf plot being a new user.
This is the error message I keep on getting from the electrical rules checker. Any advice welcome.
***** Sheet /
ErrType(3): Pin connected to some others pins but no pin to drive it
@ (129.54 mm,58.42 mm): Pin 1 (Power input) of component #PWR03 is not driven (Net 2).
ErrType(3): Pin connected to some others pins but no pin to drive it
@ (147.32 mm,88.90 mm): Pin 1 (Power input) of component #PWR06 is not driven (Net 3).
** ERC messages: 2 Errors 0 Warnings 2
if you want me to send the sch or pdf plot i will gladly send it on. I have tried doing the anotation thing,always the same error. I’m just blabbing now,getting tired.
You can look in the symbol library for a power flag. Some of your components have pins designated as “power input”. The ERC is looking for something with a power output designation to feed it. Without seeing the schematic to see if you have pins that maybe should have such a designation, you can put in the power flag. VCC, VDD, +15V, etc… Those should all be examples.
It is NOT intuitive how the ERC rules work for power sources. And, the current documentation leaves quite a bit to be desired. This is exactly one of the things that I want to fix in the documentation when I can find the time.
The power symbols need to be inputs with the way circuits are normally drawn; allowing for more then one voltage symbol of the same type to power several circuits.
The “Power Flag” is a short-cut to indicate to the ERC the location of the power “source” without changing other schematic symbols.
One can use the short-cut of adding a “Power Flag” or one can alter the schematic symbol where power actually enters into the real world design.
Additional reason: A power symbol needs to mark a net as “this needs power somehow”. (This is useful if you have a part of a circuit that only has passive components in it but still needs power.)
Does not work if you have any passive component in the power line. (Fuse, inductor of a filter, …)
The power flag is not really a short cut. It is the way to communicate where power comes from.
I have seen a lot of circuits where people simply place all their power symbols and connect them to power flags in one central location. (To get rid of the warning)
This negates the ERC for power. (ERC will tell you everything is ok even if your power connector is not correctly connected to the net marked with the power symbol.)
Always place power flags at the component where power comes from. If you have passive components in series, make sure to place the power flag near to this component.
It would be a good idea to then mark the input of this passive component as power input without also introducing a global label. (Is doable with a one pin component that has a power input pin that is visible instead of hidden like in the other power symbols.)