Tuesday, October 1, 2013

Techy Tuesday - Free Design Software

You don't need to be a design engineer to home brew electronics.  There have been electronics hobbyists since before the term electronics was invented, and while the ways of transferring knowledge have changed from the old magazines like Popular Electronics to the newer Make and other online sites, a large number of hobbyists still build things all the time. 

The home designer doesn't have to spend buckets of money on design software, a lot of free software is available.  From EE Times, we learn that Allied Electronics and RS Components have teamed to produce a suite of free software called DesignSpark.  Who?  Allied is a US company with a history stretching back to the early days of radio - they used to be Allied Radio. RS Components is better known in Europe.
Somewhere in the clouds, we have a company known as Electrocomponents PLC. This company boasts more than $2 billion of annual revenue, more than 1 million customers, and operations in more than 30 countries. The two main brands in the Electrocomponents empire are Allied Electronics and RS Components.
For building one or two of a design (yours or from someone else) or for experimenting, hand point-to-point wiring or dead-bugging will get you there.   (The name comes from how components can resemble dead bugs when they're mounted on their backs with their leads sticking up in the air).  As the components get smaller, like today's surface mount parts, or as the circuit gets faster, like a fast computer board or radio, there's nothing like a printed circuit board (PCB) to help get predictable and consistent performance.  The DesignSpark suite includes a PCB design program with full-professional capabilities, DesignSpark PCB.  They describe it this way:
 DesignSpark PCB is offered completely Free of Charge and fully featured. This is not a cut down version of an expensive product or one with a time limitation on license. (There are no intentional restrictions on designs). There are unlimited schematic sheets per project, up to 1m squared of board size and no limits on layers, which allow you to get your creativity flowing without restraints. DesignSpark PCB circuit design software can be used for schematic capture, PCB board design & layout, generating impressive 3D View to visualise your design in real time, and generating manufacturing files.
There are companies like PCB123 (Sunstone Circuits) who specialize in small runs of PCB production.  They give away design software a bit more limited than DesignSparkPCB, you design the board in this software, send them the program's output, and they'll provide you boards with very quick delivery.  The problem with these guys is that you're limited to using just them to produce the PCB. 

Circuit simulation software that can help you be sure a circuit you designed will work is available, too.  DesignSpark links to a program called "GreenPoint" from ON Semiconductor, which looks to be a SPICE-type simulator (Sidenote: SPICE, Simulation Program with Integrated Circuit Emphasis, is a program developed at UC Berkeley in early days of integrated circuits.  It is pretty much the standard way of analyzing circuits in great detail, especially for lower frequency analog electronics.)  I use LTSpice, from Linear Technology, another free program.   There are others. TINA from Texas Instruments, and MultiSIM from Analog Devices.  Here's a useful summary.

You're going to need a housing or box for whatever you build, and DesignSpark has you covered with a 3D modeling tool DesignSpark Mechanical.   And I'd be short changing you if I didn't mention Google SketchUp.  Never touched it, know almost nothing about it, but I know woodworkers are finding it useful. 
DesignSpark's demo of how they intend their mechanical and electrical software to all go together for you. 

You've got a computer.  Why not make your electronics adventures easier and better?  DesignSpark is clearly trying to sell parts and the difference between what a company might buy for some prototypes and what a hobbyist might buy is often pretty small.  They don't mind hobbyists using their software at all.  Nothing wrong with them being interested in selling, and if they make your design life easier for nothing, I just can't complain.  Capitalists! 



  1. Thanks for this post. I am downloading now and getting started. I have an idea for a VHF /UHF rig that fits in a 30 cal ammo can for FreeFor communications. Been trying to fine basic designs online with surprisingly little results. I am not an EE but I was an ET for about 10 years so if I can find a schmatic I can lay it out on a board and build it. Any help out there?


    1. Can you talk about what you want to do? VHF/UHF covers lots of ground.

      If you prefer, you can drop me an email SiGraybeard at gmail

    2. Yep in bound now.


  2. Great post, I didn't know all that free stuff was out there. Inspired me to start learning the EZNEC antenna program I got with the new antenna book. Will download these and play with them.

    1. EZNEC, and NEC programs in general, are really great to have around to play with. My antennas have all been in place for some years now and I haven't needed to do any modeling at home, but we've used it at work.

      For those who don't know, it's for modeling radio antennas. Since antennas are much more critical for transmitting than receiving, it tends to be used by hams and professional antenna engineers.

  3. The Windows-only aspect is unfortunate, but I guess I'll give it a try anyway. Got Wine, and also an XP virtual machine, so maybe it's usable one way or another.
    Been using EAGLE for many years now (and VariCAD for mechanical design, and they don't exactly integrate).