Is there a way to simulate on the PCB?


#1

Im very new in KiCad and I just will send the prototype to a cheap PCB company to manufacture like allpcb.com.
But I want to be sure if my schematics was correct. Because I simulate it in LtSpice any mistake will not be seen in KiCad.
Is it possible to simulate after routing is done in the PCB?


#2

I think not even very expensive tools have the options to simulate the complete pcb.
For chips there are tools like cadance that can read out the parasitics from the layout and simulate with them. But these tools are very expensive!

Do you really need a simulation or do you only want to check if your pcb is equal to your schematic?
The later is done with the design rule check (DRC).

By the way a simulation does not guarantee that your design works. It only shows that under the mathematical models used for simulation the design behaves as shown in the simulation. (Good models get close to reality.)


#3

I can check with DRC if pcb is equal to your schematic. But at least I want to be sure if I draw schematics correct. I redraw it from LtSpice schematics. But in KiCad I cant simulate it. So imagine I draw connect input to a wrong junction. It would be very bad and hard to detect without simulation. Is there a way to simulate in KiCad at least at schematics view?


#4

In new versions of kicad (nightly) simulation is possible. But as i said above: Simulation alone is not enough to ensure good design. (Don’t expect that you will measure the same signals as you get from the simulation. With our current technology we can not recreate reality as a complete mathematical model.

For checking the design there are limited options. You can use the electrical rule check. (ERC) It gives limited help for frequently made errors.

It is also quite hard to estimate what you need if we don’t know your application.
Simulation of digital signals is quite easy. Analog signals are a lot harder.


#5

Where is the simulation? I use 4.0.6 version and I cannot see anything related to simulation? Which version do you use?


#6

Ok. Rene has used jargon to tell you the version. There are nightly builds of Kicad. They have new features, as the spice simulation, but also could have bugs. The nightly of today will be the stable of tomorrow after debugging.


#7

nightly = daily build/repo checkout of KiCAD
stable of tomorrow = v5 (somewhen Q4/2017)
after debugging = lots of bughunting and bugreporting and testing of said nightlies


#8

Let get ALL Fact Right

ERC = Electric Rule Check … Check is all pin connected, and is the pin topology going to the right another pin topology (input to output, and not output to output) and many more, see it when you create a component, or edit some component in pin directions.

DRC = Design Rule Check … it only looks for is all pin get a trace and is the isolation between track/via/danger zone/outline/pcb high track crossover… and so on. to make sure the program can make a Gerber file

Spice = a program that calculate electronic signal, not how it shot work but WYSIWYG, this is done with only the Math where all model in you .sch require spice model Info in the model, where you as designer shoot type all relevant Parameter for this model in the specific model

Kicad Was made to make opensource or private project PCB and northing else, so do not expect some part with Spice


#9

I think there are plans to integrate a simulator. (The development version already does support ngspice)

Also: Kicad is open source. But it does not force you do make the projects you create with it also open source. (You can use kicad to design a closed source commercial project.)


#10

that require that you can see the if the model has Spice, like you can in both Cadidance and LTSpice so you don’t mix spice model with non spice model. the only thing Kicad is not good at is there library structure, and the all Kicad library is looked to a special footprint library but not all relevant footprint is in that library and you can check it before you convert your schematic to footprint to see what you can choose between. Then you have to edit the symbol to pick from another library, that is just frustrating.


#11

Of course that’s not true. As has been said repeatedly on this forum, many users prefer “atomic” libraries where symbols have footprints called out in them.