PCB simulation and layout

Started by ombz 2 years ago13 replieslatest reply 2 years ago281 views

Dear all,
This is probably an always re-occurring topic within electronics forums and one that probably leads to plenty of subjective inputs and hence: discussion. Yet I couldn't find any related thread within this forum.

I am rather from a firmware and DSP background, but I find more and more fascination in circuit design. I told myself: I want to start to design PCB's myself, so I can put my ideas into reality all on my own and have fun discovering plenty of new things. I remember that at my previous workplace all PCB designers were using Orcad for PCB design, simulation and verification. Back at university I've had to design a PCB out of an already existing (verified) schematic using Altium. However, I cannot/don't want to afford either of these big price packages. I mean, for 1k USD or more I can easily hire someone doing the task -- but that's such a wrong development of the world. :/

I've tried out the simple DipTrace which I find very intuitive to use (way more than Orcad or Altium), however I definitely lack the possibility of simulation. I first thought: I'd simply put concept, simulation and verification into another software (for example LTSpice), and then export to a PCB design software. But I started to realize that that's very impractical, time-consuming and also error-prone.

Is there really no single affordable software package (like below 500 USD) that supports the three major steps of design flow as follows?

  • 1. schematic
  • 2. simulation / verification
  • 3. layout

All afforable ones I've found only support steps 1+2 or 1+3, never all the 3. :'( On the other hand: isn't that a market opportunity? :p

If you need to know what kind of PCB's I target:

  • - nothing too crazy, however maybe featuring a small DSP and/or small FPGA running maybe up to 100 MHz or so
  • - may include RF front-end
  • - may include low-speed ADC's (max 16 MHz clock)
  • - may include other I/O devices (as may ideas evolve)
  • - all low-power (at least so far)

So I'd say any standard PCB tech will do, probably with 2 layers for the starter projects (simple MCU based) and 4 layers for my more advanced endeavours. I welcome all of your suggestions and inputs. :)

-Andy

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Reply by divnerFebruary 24, 2017

Hi,

One of the better free Cad Programs now is Kicad see http://kicad-pcb.org/ 

It is now supported by CERN and is now at a stage where it can be used for quite complex designs. It also has a fairly substantial library of Footprints and a 3D viewer capability.

Best regards,

Noel Diviney.


[ - ]
Reply by ombzFebruary 26, 2017

Thank you for the reply. I've had a look at it -- that's exactly what I was looking for. :)

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Reply by MichaelKellettFebruary 24, 2017

I use EasyPC which is quite cheap (£297 for  a license for design up to 1000 pins, lots of layers).

If I hadn't been using EasyPC for years and years I would look first at Kicad.

For simulation you can't do better than LTSpice (free download from LT website) until you are prepared to spend several $k.


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Reply by ombzFebruary 26, 2017

I've had a look at Kicad and as it's for free and seems to do exactly what I want, I'll try out that one first.

[ - ]
Reply by Tim WescottFebruary 24, 2017

Another vote for KiCad and LTSpice.

I don't think it's a good idea to try for whole-board simulation.  Break your board into logical blocks (i.e., this amplifier, that filter, some power supply or another), define the inputs and outputs to each block, then simulate (and optimize) the blocks separately.  If all the blocks work correctly, then your whole board should work correctly.

For that matter, if you're designing by doing cut-and-try with simulation then you're probably doing it wrong.

[ - ]
Reply by ombzFebruary 26, 2017

Hi Tim,

Thanks for the recommendations! That's exactly what I'll try out first. Kicad looks good to me at a first glance. :)

Sure, I don't intend to try out whole-board simulation. But even block-wise I thought it was impractical before: whenever I realized I forgot or missed something or something wouldn't work it was always some sort of double or triple work: update schematic in LTSpice then re-draw in schematic editor of DipTrace, then correct the board (if already in layout)...

Uhm, your last comment is confusing to me: to what exactly are you referring to by "cut-and-try with simulation" and what is wrong about it (or what could I do wrong)?

Cheers,

Andy


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Reply by antedeluvianFebruary 24, 2017

Upverter (https://upverter.com/ ) is a cloud based package, free if you keep all your designs public.

Altium also has a free package called Circuitmaker  (https://circuitmaker.com/ )


[ - ]
Reply by ombzFebruary 26, 2017

Hehehe, keeping designs public. Hmmm... :p

But thanks for the hint on Circuitmaker, I'll have a look at that one also, next to Kicad.

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Reply by jkvasanFebruary 24, 2017

Andy,

I would strongly recommend DesignSpark. I am using it for most of my commercialized projects. It has got everything that you asked for and its free!. And it is updated every year at least once while there is a good team that answers most of your queries.

Autorouter, Direct import of components through Excel based software, DRC, BOM generation and other features of commercial expensive software are available at zero cost.

There is a learning curve, I agree, but it is worth an effort.

One of my designs was a four layer big size board - similar to Medical PC designed with DesignSpark.


Regards


JK


co-ev-rev5_81657.jpg

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Reply by ombzFebruary 26, 2017

Thanks for all the hints, JK. I've seen that some people recommend DesignSpark. I'll have a look first at Kicad as it seems more promising to me and I like the fact that it's open-source and multi-platform. :)

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Reply by gillhern321February 24, 2017

Andy,

Well I used to use proteus you can get a pared down version for around $280.00, does schematic, simulation,  pcb design and layout alot of this functionality can be automated, will also build the gerbers and wiring diagrams automatically once all the others are completed. Also builds your component list for manufacturing. Will do a

ascii file for manufacturing or build you a netlist also.

It comes with no processor or PIC assignments components but you can build your own if you know how. And you can buy the processor/PIC components for a set price for each(addon's sigh) at a latter date if you wish.  Decent product, definitely not up to altium specs tho.

you can download a demo for free, you will not be able to save your work tho. But you can create and test your schematics and component simulation.

I dont work for proteus or anything like that just use it. I used proteus for about 5 years before I finally bit the bullet and bought altium (ouch!!!!)


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Reply by ombzFebruary 26, 2017

Thank you for all the help. I think I'll try out Kicad first. :)

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Reply by ghostdzogMarch 5, 2017

Hi,

Although i am not experienced in this area and in fact new to embedded electronics completely.

I did find some time ago a website app run by the famous CAD software designers Autodesk that is designed to help people design and create PCB's and schematics.

The basic version of the software is free, although there is also a premium version. Not sure the difference, you probably best check it out yourself with your expert eye.

The software has an interesting interface that integrates electronics simulation, schematic design and PCB design all in one connected environment. You may also order your created designs in PCB format from the site direct which i think is a useful feature for prototyping or even if manufacturing.


The website is as follows:

https://circuits.io/

Also, I think this site is very useful and even fun for people interested in learning basic electronics without the expense of buying a set of components. Kids with an interest would surely love this site.

Hope this helps.