AutoDesk Releases An Electronics Simulator Called 123D Circuits | Hacker News Reader

AutoDesk Releases An Electronics Simulator Called 123D Circuits

techcrunch.com

132 pointsblackskad65 comments

Reminds me of an old idea I had a couple years back. I assume it's a silly idea driven primarily by my own ignorance of these tools and EE in general, but it seemed fun.

The idea was to start out with some software similar to this. Something visually impressive to keep it interesting for beginners, but technically sound to make it useful to those who know what they're doing. It would be open source, internet connected, easily accessible and most importantly simple to create and share ideas.

From there, let people make some interesting things for school, work, play, whatever, ideally sharing said creations and try to raise a community around the tools and creations.

The next stage would be to add a 3D rendering component which would allow people to create "machines" that could be run by their virtual electronics. Something like virtual fabrication. The ideal being to grow those interfaces and try to lead the community towards building virtual robots (that are technically feasible).

The eventual goal would be to build a virtual world on top of all of the above tools. Something like MechWarrior, but with engineers and industrial designers building virtual mechs from the smallest components to the large mechanical fabrication and then getting into all out war against one-another, adding to the mix less technical players to partake in the human elements of combat (generals, soldiers, medics, scavengers for destroyed mechs, etc).

Probably ridiculous, and if all went well I assume it would take years of work and planning, but it seemed like a fun idea to ponder.

The kid in me loves it but simulation speed would be an issue. I don't know exactly what the simulation slowdown for circuits is, but just to give an idea, in a classroom setting, you're probably waiting a couple seconds for a simulation of a couple microseconds. Of course, this depends on factors such as simulation accuracy and circuit complexity, but it's unlikely you'd be able to scale up to robots. Intel processors take hours (days?) to simulate a couple seconds of operation at the circuit level.

One issue is complexity management. The kind of finite element software that can model fields in microwave-range hardware is, frankly, a PITA at one extreme, and at the other extreme you have minecraft redstone and an ancient computer game from the 80s called Rockys Boots and some .edu softare.

It strikes me as pretty hard to satisfy both extremes. Don't even have to go to extremes. Forget exotic microwave work an just try to have the same software and user interface model both a stereotypical ham radio dude 20M dipole and simultaneously be usable for a kids arduino LED blinker and make a simple flashlight.

I would claim that minecraft redstone is a local maxima and you'd do best to try and extend/mod it. Someone out there probably already has (or should have) a mod to add basic logic gates in redstone, rather than simple plungers which already exist, how about simple robot arm joints in minecraft?

I like it. Sort of like Mechwarrior meets Minecraft meets My University Education in Mollecular/Astrophysics. I suspect the major issues would be with time scaling between user perspectives (a huge issue in MMO games), the learning curve, interface and simulation accuracy.

http://www.circuits.io/

http://upverter.com

Not just for kids anymore.

I wonder if it models the terrible parasitics of a real breadboard.

I imagine it would be really annoying for beginners to build an IR receiver (or whatever) with the software, have it working perfectly, then try to build it on a real breadboard only to spend hours frustratingly trying to figure out why the circuit is oscillating.

Welcome to EE lab. In one lab as an undergrad, my partner and I found that we could get our circuit to work by attaching a capacitor with one end to our circuit and one end to a random place on the breadboard. It made for a bit of a funny circuit diagram in the write-up where one end of this capacitor was connected to nowhere.

Ex EE here (RF/mixed signal). I always modelled it as everything being connected to everything via a tiny capacitor and a big resistor in parallel. This allowed a few odd scenarios to be reliably identified, especially in UHF frequencies and above.

The trailing capacitor just had a large value invisible resistor attaching it to your circuit somewhere :)

Is there any software out there that includes these real-world models into the design side?

Yes, but its usually not worth the time to include all parasitics in a model until you get to very high frequency work.

Professional circuit/PCB designers already know roughly what the issues are going to be and can order of magnitude approximate well enough to know if its worth fully modeling or not. For novices, just understanding what the parasitics are is hard enough, much less adding them to a circuit that is often already fairly complicated for them. Most lower frequency stuff that novices will be building should not have an issue with parasitics, but pushin breadboards are just awful and the most common hobbyist op amps have plenty high enough gain-bandwidth-products to bring them into play.

mbell is right -- rather than just adding parasitic capacitance and inductance estimates to every node, it's more helpful for the engineer to be able to evaluate and discover which nodes are particularly sensitive and which aren't. Start with some back-of-the-envelope order-of-magnitude estimates (maybe guess ~1nH/mm inductance for a wire, ~1pF capacitance between adjacent pins), and an experienced engineer will already be able to eyeball likely trouble spots in your circuit. The novice can certainly use the same concepts with simulation to do quite a bit of "debugging" in just a few minutes, for example dragging around a 1pF cap between a bunch of pins, re-running the simulation each time, and seeing where it has the most detrimental effect on an analog circuit.

Just to add, if you want to 'fail safe' a breadboard design, your better off assuming ~25pF of stray capacitance per breadboard insertion point. You should also make sure your circuit bandwidth is less than ~8-10Mhz, keeping in mind that if you have an opamp with GBP of 20Mhz and you're using it with a gain of 2, you may have a problem. Stray inductance can also play a part, but it's far less likely.

Umm, Spice[1]? I don't have a good model for a rusty piece of tin, but maybe someone does.

[1] Like all cheapskates, I use LTSpice.

Yes, you can use something like AWR or ADS. Although they cost megabucks.

You can always measure the capacitance between each row. Hell of a lot better than building a full circuit first, just to find out your BB sucks.

That usually doesn't help as a large source of the problematic parasitics is contact between the part's leads and the 'grippers' inside the breadboard. Lead diameter, corrosion, 'gripper' spring strength, etc all come into play there.

So if it's so random that you can't reliably measure it because it changes every time you plug and unplug the same pin (let alone different pin diameters), how can software hope to model it?

When I say 'model it', I mean that loosely, perfect modeling of electronics circuits isn't realistic anyway, any modeling worth the effort will assume a range of possible values for anything under test. A simple example would be if the software warned the user that an active filter design was dangerously close to instability and thus had a decent chance of oscillating when real world parasitics are present.

I realize I'm posting late but its modeled the same way you model tolerances everywhere else.

There is no such thing as a 1K resistor as in 1000.000 ohms. At least not unless you pay an insane amount of money. What there is, is a random-ish spectrum of values where sorted into EIA "preferred value" bins, 10% tolerance resistors that are too high to fit in the EIA E12 bin of 820 ohms, but too low to fit in the EIA E12 bin of 1200 ohms, are by definition dropped into the EIA E12 bin for "1K" resistors.

So a lot of (good) modeling work is screwing around with placing the "wrong" value resistors, simulating, and seeing what happens. So you've got a budget constraint such that you'd like to use cheap 10% resistors. An a theoretical equation said 1063.237 ohms is just right. So you'd superficially think simulating a 1K resistor is good enough, but you really need to simulate what happens when you insert a perfect 820 or a perfect 1200... Will it explode and kill people, or merely clip and distort into a guaranteed product return and/or unhappy customer? In which case its time to start fighting with the boss to spend some extra nickles (times millions of units) to install 5% or 1% resistors. Or maybe it doesn't matter and you get to save some dough.

What makes it even more exciting is quite a few performance characteristics depend on multiple devices. You're not building a little small signal RF amp with one real world random resistor in the bias ckt and every other component is theoretically perfect. No, both your base bias resistors and collector resistor and transistor beta and everything else is "fuzzy".

There exist semi-automated tools to fuzz-n-sim for the pros... this will only confuse the heck out of the noobs so its not often discussed.

Imagine if when you wrote code, you didn't really write "if-then" and "do-while" and "for-loop" but really wrote things that are within 10% of a "do-while" almost all the time, but its never really perfect. And that's what EE work is like. Fun, eh?

Each time you virtually plug something in the program's breadboard, generate a random number. If the number is lower than a threshold, prevent the connection from working. Change the threshold at every program loading and randomly during use.

Haha I assume you're joking; that would give the user zero benefit and immense pain.

I think there is a lot of value to blowing up your Arduino for reals. When you blow up a couple of Arduinos, you'll tend to force yourself to learn very quickly why it is happening and how to avoid it.

What is so bad about "blowing up a capacitor" or "burning yourself with a soldering iron"? Capacitors are a few cents, each. Buy them in bulk and never worry about needing one again. Soldering iron burns are easy to avoid if you have spent any time in a kitchen.

I feel like this is missing a big point. Arduino is the safe, easy entry point to learn electronics. The danger is miniscule, and whatever danger that is there, is part of the learning process. You need this as much as you need a rice-cooker simulator.

As somebody who is learning electronics using Arduino right now, I almost agree with you.

WARNING: The first time I accidentally forgot to put a resistor in front of an LED and sent 50mA to one which was rated at 20mA, I expected it to fizzle and cut out like a regular incandescent light bulb does in my house.

When it literally exploded and the plastic covering went flying through the room, I was very very glad it didn't hit me in the eye, or I'd probably have done some fairly serious damage.

Yes this is always 'interesting'. I'd personally suggest that everyone at least stuffs the following components over a 30v DC 5 amp supply (in a fume cupboard with goggles on) at least once just so you know when to wince: electrolytic capacitor reverse polarised, 1 ohm resistor, generic npn transistor (base-emitter forward biased), various LEDs, signal diodes.

you learn to double check your circuits first then :)

What about getting your H-bridges the wrong way around and the smoke hitting the ceiling... the night before your final project is due?

> "I feel like this is missing a big point. Arduino is the safe, easy entry point to learn electronics."

An Arduino Uno costs about 25USD. Blowing up a few of those, or other components gets pricy. This service lowers the price of entry to almost zero, which is a pretty big deal for people with low disposable income or limited access to the hardware.

There are so many people that underestimated the potential success for Arduino, and the rPi. Also, experienced hardware folks tend to forget how unforgiving hardware can be to non-hardware folks, and beginners; a good example of which was posted here the other day. http://www.jwz.org/curtain/

> so many people that underestimated the potential success for Arduino, and the rPi

I like the Arduino and Raspberry Pi very much, but they are not the pioneers of this idea.

There have been a whole bunch of electronic prototyping systems aimed at hobbyists in the decade before Arduino and Raspberry Pi hit it big.

Just to name a few: Parallax Basic Stamp, the Micromint PicStic and Domino, X-10, MIT Media Lab's Programmable Bricks, Gumstix, Phidgets, Teensy USB Development Board, littleBits, LEGO Mindstorms, Bug Labs.

I was cheering for several of the above, and they met with various degrees of success. It seemed obvious to me that they should become enormously popular, as big as the Arduino and the Raspberry Pi, but they didn't. There were probably dozens more that folded up and disappeared.

What I'm trying to say is that it took a lot of iterations of design, business model, functionality, and being at the right time before a couple companies found just the right formula to make it really big.

Nice, I've been wanting to motorize my curtains for awhile. Glad jwz did the hard work for me.

Agreed, although the integration with a schematics editor and PCB board design tools seems nice.

> it allows you to learn electronics using a virtual Arduino board and breadboard without blowing up capacitors or burning yourself with solder on your work table.

With autodesk prices, i can probably buy enough caps and pay someone to solder for me.

All of their current 123D software is free for all: http://www.123dapp.com/create

And I recently was impressed to learn that they offer free licenses for most of their professional software (including Autocad) to school teachers, university faculty, and degree seeking students.

Qualifications: http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=12311...

Software: http://students.autodesk.com/?nd=download_center

Perhaps you're thinking of Autocad. They also sell dead cheap end user software, even on the iTunes store.

I'd kill for an app like this that would help teach you electronics at the same time. I've wanted to start doing some robotics stuff, but haven't found much in terms of useful learning resources outside of just buying a full university textbook and hoping for the best.

Funny you should mention that, I've been slowly working on this idea for a circuit-sim that basically teaches you electronics, to be eventually complemented with video-lectures which I keep putting off due to school and a hunger for other projects.

So yeah, the Autodesk news was kinda depressing, but really, that just means I'm going to focus more on the teaching end and in adding my own personal style to it through quirky graphical elements that harken back to the 8-bit era of yore. Autodesk can't sell a product with soul.

You can check it out if you want. Just to warn you though, my html abilities are a work-in-progress, so don't be surprised if you see some awful mistakes in there, or if it renders kinda funny if you have a small screen.

www.bighugebreadboard.com

I actually created it to teach myself electronics, so the biggest hurdle has been learning how various components work, and then adding them to the sim. Also, prior to this, my javascript knowledge was basically acquired through Codecademy.

I'm also putting some of the code on a Github repo, as in I plan to make it open-source. Alas, before I did that I cleaned up some prior amateur's mistakes without thinking of the bugs I would be opening up. I should have them fixed by tomorrow morning.

https://github.com/Bjorkbat/electricjs

That looks awesome, I am definitely going to check it out.

Buy an Arduino/Launchpad/MSP430/other prototyping kit and start plugging things (motors/LEDs/other devices) into it. As long as all of your devices will work at the same voltage -- as long as everything is 5v or 3.3v or whatever -- they plug into breadboards like legos.

It took me 3 months from buying my first Arduino to using an ultrasonic distance sensor to control an RC car motor. http://gilgamech.blogspot.com

I guess I'm not seeing the advantage over existing software.

Unless there are some tie-ins with their other 123D software to, say, automatically create a hardware enclosure from a schematic.

We have that! Just push the "generate enclosure" button in the circuit details page.

Cool! I'll have to check this out then. I love 123D in general, it's like Inventor, only free!

That has long been my Achille's heel - I can EAGLE a pcb pretty easily, but woodworking / 3d interlocking Ponoko designs elude me.

How do I add a voltage other than a 9V battery?

What are the current alternatives to this? I'm looking to build an LED driver (possible IC candidates are Linear LT3477, TI TPS63020 and some other TI / Linear chips). I'd kill for a software that would simulate any chips (or even just a crude approximation of them).

This is an issue we've been tackling at CircuitLab (https://www.circuitlab.com/), and the fundamental issue is that the chip makers (Linear, TI, Analog Devices, etc) don't want to let their device models out of the building. They often do have simplified models for simpler parts (op-amps), but for more complex mixed-mode parts (switchers), coverage is sparse, and a SPICE netlist is a poor language for encoding the control logic. LTspice, for example, includes encrypted models for many of their switching power supply parts, and those include special non-standard SPICE behavioral components to make the models possible to execute in a reasonable amount of time. Other companies with web-based / server-side simulation keep the models entirely opaque and tremendously limit your ability to configure the surrounding components. The goal is to get you just far enough to have confidence that their chip is the solution for you, and then get you to use their tools and field application engineers. This is the status quo and they're generally not in any rush to disturb it.

LTspice [0] is an excellent (and might I add free) SPICE simulator. Linear includes proper models of the majority of their chip lineup, including LED drivers. Their power supply IC models are also excellent. You can simulate a full LED driver circuit and a whole lot more with LTspice. TI also has a similar SPICE simulator [1], but it's not nearly as good, and its simulations are much slower and a bit more unreliable.

I design electronics for a living, and I use LTspice all the time for power supply and analog circuit simulations.

[0]: http://www.linear.com/designtools/software/#LTspice

[1]: http://www.ti.com/tool/tina-ti

Worth pointing out too that most major semiconductor vendors provide SPICE models for their parts. Maxim, for example, has an extensive set of models for their chips: http://www.maximintegrated.com/design/tools/modeling-simulat...

Thanks, that helps a lot! Giving it a shot right now.

How long should it take to make a high-power (3A+ @ 3V, buck-boost IC) LED driver, very approximately?

If by "make" you mean create the schematic in LTspice and simulate it, then I would guess about an hour or two (mostly because this might be your first time using LTspice). If Linear has a part that already meets those requirements, it should be a very straight forward affair.

Is this based on Fritzing (fritzing.org)?

Nope, just a non-free clone with a marketing budget.

I must say I'm not sure how to feel watching the maker and hacker culture I love so much having its open heart slowly ripped out.

To be honest, I lost faith in maker culture and open hardware in general around the time MakerBot went closed hardware - not because of MakerBot themselves, but because of the way their critics were treated.

MakerBot themselves base their designs heavily on both the open hardware RepRap and open designs by other commercial manufacturers, and their head honch Bre Pettis was a big proponent of open hardware and maker culture - even publicly humiliating newbies to the community on his blog for failing to the files associated with their designs, insinuating that they were somehow undermining the maker community. [1] (In reality, they were trying to but couldn't figure out how because they used their PCB house's free proprietary software which couldn't export - we're talking a tiny hobby operation here.)

Then he went against the very principles he publicly shamed others for failing to follow and turned MakerBot's hardware and software proprietary in order to make more money.[2][3] All the people who politely but firmly criticised him for failing to live up to the same standards he held were accused of using "language similar to that we usually hear from people who blow things up" and "fundamentalism" by another maker[4]. This was linked supportively by one of the most prominent companies, Adafruit.[5] Anyone who suggested that comparing other members of the community to terrorists was incredibly inflammatory itself, or linked Bre Pettis' own views on others who took open hardware closed, was labelled a "troll" and had their comments deleted. People who correctly figured out that MakerBot was taking their hardware closed based on Bre's non-denial denial[6] were called liars and accused of spreading rumours. Remember, Bre's own public humiliation of newbies with much less power than him didn't get this kind of criticism.

So yeah. I'm basically done with open hardware and the maker community. It looks like a way of suckering people into doing big businesses' work for them and then labelling them terrorists when they ask said businesses to uphold their end of the bargain. I guess it's profitable for some though.[7]

[1] http://www.makerbot.com/blog/2010/03/25/open-source-ethics-a...

[2] http://www.hoektronics.com/2012/09/21/makerbot-and-open-sour...

[3] http://openalia.wordpress.com/2012/09/22/the-definitive-make...

[4] http://www.tigoe.net/blog/category/open-innovation/408/

[5] http://www.adafruit.com/blog/2012/09/21/in-defense-of-open-s...

[6] http://www.makerbot.com/blog/2012/09/20/fixing-misinformatio...

[7] http://allthingsd.com/20130619/makerbot-sells-to-stratasys-f...

You can look at it as a kind of validation of the community - there's commercial interest in it.

Also, just because someone starts on this app, doesn't mean they won't move on to something else later.

Well, I agree if you s/validation/co-opting/

No, it doesn't necessarily mean they won't move on to something else later, but they're now living in a universe where it will always be Autodesk's job to make that harder or less obvious to them. By any means available.

I'm not sure keeping hobbyists locked to a particular platform is that useful to Autodesk, especially considering the prices they charge for higher level software.

If it wasn't Autodesk doing this, would you have the same reaction? What about Makerbot's move away from open-source?

I would have exactly the same reaction - I don't have any issues specific to Autodesk, apart from those that I've expressed here related to their 123D suite.

One could argue that Autodesk's killer feature here is simulation; afaik, Fritzing doesn't have that feature.

If you (or anyone else reading) haven't already, go read Steven Levy's Hackers. This is sort of the theme of the latter half of the book.

that was the first thing to go through my mind -the graphics look _extremely_ familiar.

It doesn't seem as in-depth as something more pure electronics like this: http://www.falstad.com/circuit (also as iCircuit for iPhone)

They really went out of their way to try and rip of Github, it seems like a lot of sites now would rather copy it because developers are used to the design.

For someone who's been looking for an easy point of entry into learning this stuff (me), this looks awesome.

Arduino is already the easy point of entry for learning this stuff. Stop talking about it and just do it.

Okay now we need a code debugger with breakpoints. Then, real hardware in the loop!

Working on it!

Is this similar to Upverter?

Sure seems like it.

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