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Why Fritzing Needs a Simulator

L G 9 years ago

As a realtively new person at using the Arduino, I find Fritzing to be an interesting tool. But it would be far MORE useful if it had a simulator. It is extremely easy to misplace a single node on a breadboard. So just because I have created a working circuit on my breadboard doesn't mean I will not make a single mistake in copying that circuit design over to the Fritzing program. And one misplaced node can shut down an entire circuit. I would not want to go to all the trouble to prototype an actual PCB and make it, only to LATER find I messed up on a single connection. I just don't see how one could ever trust such a design program without having a way to test the circuit once it is drawn, to make SURE no mistakes were made.

If building in a simulator is not something you wish to do, perhaps you could consider creating an interface that could take the schematic from the Fritzing design and load it into a popular (and affordable!!)  simulator program, such as Tina Design Suite. Then it would be a very valuable part of a complete design and testing set of tools.






inoxidabile 9 years ago

Hi Zoandar,

I sent  a similiar question some time ago and Jonathan answered me that it has been a specific decision.

I see his point of view and I understand that it could be more "educative" to have and conserve a contact with the real world if we want to be really creative, but...

Maybe, it 's better to leave "the door open" with the ability to interface with a simulator (or at least to have a compatible output).
So I think that it's worthy considering your request - even if I prefer other kind of software simulator...


L G 9 years ago

Hi inoxidabile. Thanks for the reply!


I suppose each simulator has its merits. FWIW, I chose the one I did for several reasons.

1- it has the components I use most often already built in

2 - It is "affordable" to me as a hobbyist. (They actually had it 50% off the day I decided to buy it, which was a very pleasant surprise! :)

3- It doesn't require me to be an EE to understand how to run simulations like some do ( I won't mention any names - they give me heartburn ;)

4 - You'll laugh at this one if you are a professional or EE, but to me it is important - The LEDs used in my  circuits  light up when the circuit is in active DC simulation (if I have not made any mistakes). :) An invaluable quick indication to me that I am on the right path in the design.

To be most useful I suppose a Fritzing integration option would need to be able to talk to most all the simulators out there. Whether that is even possible I have no idea, but I presume they each use their own proprietary file format, so that won't make things any easier. Still, it would take an already impressive Fritzing program and make it really rock if it also had a simulator! And if it were still free I'd bet you would have an emormous following immediately. In fact I would have bought it at retail, had it been available when I did my recent shopping for a simulator.

Have a great day!

inoxidabile 9 years ago

Hi Zoandar,

thank You for the arguing!

About  the simulator, I would only say I'm not  so expertise  to use great simulator - my note was based on a  "personal taste".  I tried a lot of simulator and in my opinion the best is  5Spice, on terms of simplicity.

But, following Your reply, it seems You are focusing not on the output type  (it could be as standard spice or whatsoever)  but on the support in terms  of direct response.

I think that this point of view could become a new important consideration for add these feature... maybe, after this, the developer will  reconsider their opinions.

Have a nice day!

L G 9 years ago

Hi inoxidabile,


I have to smile every time I see that word "arguing". I grew up on a farm with 3 siblings, and it was quite common for us to sit around the kitchen table with Dad and carry on vigorous "discussions" (debates sometimes) in the presence of Mom. She would always say "why do you guys always have to argue all the time?" At which point we would tell her we were not arguing, we were having a discussion!". :)

Pragmatic observation has been my best and strongest tool all my life. I am pretty much self-taught in all I do, including my hobby interests in electronics. When I read the "getting started with Arduino" book, in the beginning it was like the author was dewscribing my very own childhood! I have always loved to tinker with things and it has taught me to be self-reliant and how to fix all sorts of things. I am never afraid to try, no matter how complex the thing needing fixing seems from the outside. But I like cutting to the chase, so I always look for the fastest and easiest way to accomplish my goal. I guess that is why direct response is so appealing to me.

I also have QUCS simulator, but in order to tell that an LED is "on" in that, you have to look at the current and voltages on both sides of it and reason it out. So much simpler to see the thing glow when conducting. :) Plus it is a confidence builder to get immediate positive feedback when you are learning something new.

I have made an influence on the developers seeing this differently, that would be super! I think a lot of people interested in Arduino will come from a hobby aspect, and they may not know much more than I do (which isn't saying much) so would surely welcome such an addition to Fritzing.

Have a nice day too!


inoxidabile 9 years ago

Hi Zoandar,

I think to know exactly what you feel... I'm also a practical person and I also grown up in a farm.

Like you, I still have the preference of the "short and to the point" solutions.

Some years ago, when I started with microcontrollers (Microchip PIC) one of first tool I looked for was "something" capable to show that the led is on/off or that the display indicates the right digit before to build the circuit.
Now I still use that tool - I'm not a skilled programmer - and I looked for "something" similar for Arduino, but without a great luck, except the following... maybe it isn't the same thing you are speaking about, but I would send you a link:


In my opinion, a mixed simulator (hw+Arduino) could be very hard to develop and, maybe, it could be more wise to leave separate the two topics.
I see Your point of view, but it's not a question of arguing or not or if it's worthing  to discuss, in my opinion it's better to see th topic in its mutiple aspects.




L G 9 years ago

I had discovered Virtual Breadboard before I found Fritzing, but thank you for the link.

It seemed like exactly what I was looking for. But the reason I kept looking for a simulator after trying VBB is that I cannot make it work properly. If you are familair with it, perhaps you could help me figure out what is wrong? I can get it to run the built in examples without a problem. But when I try to follow their "Creating an Arduino Project from Scratch" tutorial, which is exactly the same as the built in Blink LED example, I can only get as far as step 7. When I add the Blink.pde source code to run the project, after a couple seconds I get a "VBB has stopped responding" error and the program closes. This happens on both my WinXP Home SP3 notebook and my Win7x64 Home Premium PC.

I have the listed "required files" installed on both computers. I think there is probably something missing in the instructions for the tutorial, but being new to this I can't imagine what they might be. As I go through steps 1-6 the program window seems to look just like their provided Blink example which does work. If this topic should not be discussed here, perhaps we could continue in PM or email? The support forum for VBB seems pretty vacant.





inoxidabile 9 years ago

I'm sorry, but I don't know the use of VBB... my suggestion was only for the link!

I've just a very little bit more experience with the other simulator I mentioned (for PIC, it's Oshonsoft).

Moreover let me add there are a lot of nice projects but without enough supports or background... I've been interested also in a sort of graphical environment ( but they also seem in a standby state...

Of course they are all "not payed software", then we cannot expect nothing!

At this point, I can only say: if You will find something better... please tell me!


ps: I apologize for my bad english, it isn't my native tongue

Brendan Howell 9 years ago

I can certainly see why folks would want a simulator.  It would be really cool to flip a switch and see something happen on the screen.  The problem is that it gets crazy complicated to just to simulate a blinking LED.  Let's take that as an example:

- So first we have to simulate the whole Arduino board with a computer in a computer which has to be built and distributed with fritzing.

- We have to build in the compiler and full Arduino library.

- Now once the signal is outside the Arduino, we need to keep track of the state of all the outputs and keep it in sync with our external simulation. 

- So then we need to build in SPICE and which simulation type do we use DC? AC? Transient? It depends on what you kind of circuit you are building and what you want to test.

- Now every part in Fritzing needs to be updated with a reference to appropriate SPICE models.

- Next, if the LED is to blink, we need to expand the parts to include some sort of animation parameters.

- We will need a whole new UI to control playback as well as graphs and navigating the voltages and currents at any point.

- And we have not even gotten started talking about sensors and inputs yet.  How do we simulate bending, knobs, temperature changes, light input and then sync that back up with the arduino simulation? Simulation is not very interesting if it only works for LEDs.

So now we are talking about thousands of lines of code, months of development, external dependencies and dozens of new bugs. It's giving me heartburn just thinking about it. All of this so you can see an LED pulsing on the screen!  We though about this a few years back and our response was essentially "Dude!  Just build it and plug it in!  If your LED doesn't light then turn it around."  This means that Jonathan has time to work on things that are more generally useful like the autorouter, nicer UI, fixing bugs, new parts, etc.

That said, there's no reason somebody else couldn't come up with a way to export a netlist and run that through SPICE to make a few simple graphs.  Anything beyond that seems very ambitious to me.


André Knörig 8 years, 12 months ago

André Knörig

One more note about the original post in this thread. The discussion here circled around a full-blown simulator, and I think Brendan clarified what kind of a task that would be.

The original comment, though, was about preventing mistakes. One thing you can currently do is to check your layout in Schematic view, as it is much easier to find misplaced connections there.
What other EDA tools are usually offering is an electrical rules checking (ERC). It is basically checking things like whether you have shorts, incompatible voltage levels, and if outputs are connected to inputs. This is something we have already looked into quite a bit and it would be doable.

What do you think?

Jonathan Cohen 8 years, 11 months ago

One last point.  Arduino is not the only microcontroller family we support.  So for completeness, we would have to simulate other microcontroller families as well.

- j

pcook911 7 years, 7 months ago

I know that this is an old forum but I found it while searching for information on Arduino simulators.  Let me first say that I have downloaded and messed around with the Fritzing software and found it very cool.  I love how you get a visual layout showing your Arduino and it's wiring and other hardware involved in your project.  I too think that it would be wonderful if a simulator was added.

I know that there would be a lot of work involved for the Fritzing staff to do all of this.  I wonder if the solution lies in working with manufacturers of boards and components.  I know that in the CAD/BIM/3-D Parametric Modeling/Construction world component manufacturers make available their components to be added to existing layouts.  This allows the user to focus on the design of the project as a whole instead of taking the time to model a a single component.

Maybe the Fritzing group could look into creating a system that would move some the burden to component manufacturers.  The component manufacturers products would be more attractive to users as a result.

I hope I got my point across.  If such a system was in place using Fritzing's software I would be the first in line to buy it and put it to use.

Chipmuenk 7 years, 4 months ago

Just wanted to add my 2 cents to this discussion ... I was (and am) looking for an intuitive software for designing and layouting analog and maybe mixed-signal circuits for my students. Fritzing looks like the perfect candidate - intuitive, friendly, unthreatening to beginners.

Most non-EEs probably won't even notice the lack of a SPICE simulator / simulator interface as breadboarding is more intuitive. Hence this concept probably makes sense for the target group.

However, as less and less ICs become available in DIP packages, breadboarding becomes increasingly difficult, limiting the use of this great software. Integrating a full blown circuit simulator, possibly one that allows co-simulation with a uC is certainly out of the question. But would a SPICE-netlist export option really be so difficult? Arduino (or any other uC) could be just an empty I/O box for the SPICE simulator. Unfortunately, this missing feature is a killing point for my targeted use (and I guess for others as well who are not focussed on Arduino-centric designs).

Still, fritzing is an amazing piece of software that hopefully convinces many more people that circuit design is not black magic :-)

Jonathan Cohen 7 years, 4 months ago

Hi Chipmuenk,

Maybe you are the first to present the idea this way, or maybe I am finally hearing what people have really been requesting. But since we already export both a BOM and an xml-based netlist, and since you provide a good clue how to deal with microcontrollers in this context, I agree that it would not be such a big leap to export a SPICE netlist. So I am adding this to the issue tracker forthwith.  


- j


uaneme 7 years, 4 months ago

I also like to see a simulator in Fritzing.

but what about a semi virtulal Duino? A direct serial link over USB to simulate the software IN the hardware.

This would allow you to have one Duino linked to the PC all of the time and run the software from the pc in a "software development mode" this way it is possible to build with parts on the breadboard that are not yet available as a part in the fritzing library.

this software-simulator-on-hardware might for now be more usefull then a hardware simulator sine the fritzing library is still somewhat limited. No ATtiny, no neon bulb, no touchscreen, no pololu, etc.




Jonathan Cohen 7 years, 4 months ago

Hi Uaneme,

This is an interesting idea--we actually got a pretty detailed proposal for something like this as a Master's project at the Second Fritzing Summit.

Setting aside for the moment the arguments in FAQ #1 and Brendan's comment above, let me throw in a couple of extra points.

1. If you already have an Arduino in the mix, then why not just build the whole circuit there. What is gained (as I understand your idea) by running a simulation partly in Fritzing and partly on the real board?

2. There are lots of different Arduinos, would we have to support all of them?  What about the other microcontrollers available in Fritzing?

3. Fritzing is a small, perperpetually under-funded project and we aleady have a very long list of "basic" features to build or improve upon. If someone wants to dig up a grant to support a subproject of this magnitude, we would not turn it down.

- j 

sleemanj 7 years, 4 months ago

Given that Fritzing isn't likely to get simulation ability, perhaps the FAQ could at least point to some useful resources.


The falstad simulator applet is good for interactively fiddling with at least analog stuff:

(Free, run in browser)


New Wave Concept's LiveWire (and associated) is similar in terms of it's ability to interactively simulate and observe ("live") circuits, but supports also simulation of various logic chips, registers etc.

(Unfortunately it's commercial software)


And of course the various spice systems, but personally, I think they are too complicated for the target audience of Fritzing.  CircuitLab ( is probably the easiest free way to do something SPICE-like.





IvanAks 7 years, 1 month ago

Hi, I'm here to add another word on simulators. I wish the fritzing software would do simulations for the following reasons:

1. As I am often focusing on programming it would be more convenient to test my programs on a simulator instead of having to make and carry the components around from place to place. 

2. When I want to experiment with a new sensor or new component I may not wish to order, wait to hear its not in stock before beginning the testing and trialling the software. 

3. simulation can save on bad design where I put too high a voltage on a component. 

Please reconsider your stand on simulation.



srhart 7 years ago

You can also take a look at (see bottom of page for free emulators) and use these to feed data into the simulators in the sleemanj post.

Now if someone could take the designs in fritzing and pass them to the falstad app that would help the workflow.... 

gabrielmcf 7 years ago

I have recently knew Ftrizing and found fantastic what it can do. Its really easy to use, usefull and well made. But I miss a simulator in it. It could be a separete mode, or window, or even a plugin. But it would be great to do the simulation with the beautiful design that you have made.


I really hope the developers change their minds about doing it!


Congratulations for the work!