Merging modern software development with electrons and metal

If you want to learn MCAD or make models to build in your garage, there are a couple of new choices:

• Siemens PLM Systems is making the student edition of Solid Edge available to basically anyone for free.  Limitations include no commercial use, files incompatible with commercial Solid Edge, and watermarked drawings.  See Deelip’s post for more details.
• ASCON has introduced Kompas 3D-Home for $50.  David Levin says that Kompas 3D-Home cannot be used commercially, but otherwise has no limitations.

Recently, I needed to compile some code for Visual Studio 2003, which I don’t have (I have VS 2002 and VS 2005).

The obvious approach is to convert the project to VS 2005, which uses .NET 2.0.  However, I wanted to compile to .NET 1.1 for various reasons, and VS2005 does not allow this out of the box.

The first approach I tried was using the MSBee program.  MSBee is a program for MSBuild to allow compiling a program in VS 2005 to .NET 1.1.  MSBee requires modifying the project file, and has to be run from the command line.  I gave it a try, and it gave me a lot of errors.

I probably could have figured out those MSBuild errors, but I found a better solution: SharpDevelop 2.2.  SharpDevelop typically allows you to compile to either the current .NET version or the previous one.  So SharpDevelop 2.2 can target either .NET 2.0 or .NET 1.1 — and it can read and convert VS 2003 project files.

Sharp Develop read my VS 2003 solution files without a problem, and I went to the Project menu, selected Project Options, clicked on the Compiling tab, and set the Target Framework to .NET Framework 1.1.  Success!

The reality: there aren’t any automation trade shows in Silicon Valley.  Here are my ratings for the closest:

1. Semicon (July) has the most automated equipment (mostly wafer robots and back-end wire bonders) and vendors.  I’ve found some good new products at Semicon, but not many.  Heck, even most of the local automation distributors skip it, since the substantial exhibition costs outweigh the benefits.  I’ve skipped it the past few years.
2. Photonics West (January) has very little; typically there are a few data acquisition vendors and some lab automation oriented vendors.  Last time I went, there were a bunch of companies with serial or USB stepper motor packages with horrible, “intuitive” simple protocols.  Sometime I’ll write a rant about how I hate those; maybe it’s OK if you’re truly doing something simple and you’ve only used one brand, but I’ve used way too many different ones.
3. Embedded Systems Conference (April) typically has nothing directly related to factory automation, but I enjoy going because many of the underlying products are here, such as microcontrollers (MCUs), digital signal processors (DSPs), Field Programmable Gate Arrays (FPGAs), and Real Time Operating Systems (RTOS).

I’m not interested in being a 3D Mechanical CAD (MCAD) journalist, but since has lot happened in the last year, it’s time for my summary.

The “Big 4″ have been up to a lot:

• SolidWorks is being brought closer to its parent (Dassault Systèmes).  It’s highly probably that a new version based on the CATIA V6 CGM kernel is coming, possibly cloud based.
• PTC has put Pro/E out to pasture, and is busy trying to get its new Creo components out.  Creo is supposedly to be modular (including history based and direct modelling modules) and app-oriented.  The vision sounds nice, but I suspect that the actual operational and pricing details will make it evolutionary, not revolutionary.
• AutoDesk is adding direct modelling to Inventor via the Fusion program.  The free 123D program is a cut-down, stand-alone version of Inventor fusion.  123D looks quite useful, but I expect it’ll be neutered if it starts to impact Inventor revenues.
• Siemens PLM Systems is finally getting its Solid Edge act together.  They’re concentrating on making Solid Edge the best program for machine design, and Synchronous Technology V3 (direct and history based modelling) has been getting good reviews.

There’s been even more change with many of the smaller players:

• 3D Systems recently bought Alibre.  A few months ago Alibre introduced a $1500 bundle consisting of a RapMan 3D printer, Alibre Design Personal, and MoI.  I’ll be interested to see what happens next.

• The $97 Alibre Design Standard deal really was a great deal, just for the translators and 3D PDF output alone, but the recent pricing and capability changes (e.g. removing almost all import and export options from AD Personal) really neutered the entry level version.
• I’m hopeful that 3DS will provide resources so Alibre can keep improving (especially since I just paid for Alibre maintenance!)

• On the positive side, ZWCAD is trying to treat customers well, there have been no US layoffs as far as I know, they have been investing money into ZW3D (licensing more components, adding more developers, etc), appear to be listening, and probably have a good upgrade policy.
• On the other hand, it’s taking a  (long?) while for them to get up to speed, they’re going to a reseller-only approach (e.g. you have to contact your reseller to upgrade), and they really need to spend some money and hire some good US marketing folks.
• For example, when ZWCAD took over, they gave all customers a free upgrade to the next level.  So if you had VX Innovate, you got upgraded to ZW3D 2010 Standard, if you had VX standard, you were upgraded to ZW3D 2010 Professional.  I think this was a great gesture, but ZWCAD never received any publicity for this.

I plan on discussing my experiences with Alibre, ZW3D, and 123D, but I won’t make any promises on how often I’ll have time for such posts.

There’s always one company has has to different.   Back when Maxtor was independent, they spun their disks backwards from everyone else, and numbered their heads from top to bottom, instead of bottom to top like everyone else does.

Microchip is acting the same.  When everyone else, it seems, is using ARM cores for microcontrollers, they picked MIPS cores for the PIC32 micro-controller (MCU) family.  Their new IDE, MPLAB-X is based on NetBeans, instead of Eclipse.

I don’t think the MIPS versus ARM core is a big deal; maybe Microchip got a much better deal from MIPS.  Switching between ARM MCU vendors isn’t easy because all the peripherals are different.  I wouldn’t be surprised if it’s easier to port C code from a PIC24 (16-bit proprietary) to a PIC32 (32-bit MIPS) than from (to take a random example) an Atmel SAM7 to a TI Stellaris MCU simply because the peripherals are much more similar on the PIC MCUs.

On the other hand, I don’t see the advantages of NetBeans over Eclipse.  Both are Java-based IDEs.  Both are open source.  Both are cross-platform.  (Note that an IDE based on either one might not be cross-platform, depending on device drivers for emulators and such.  TI’s Code Composer Studio V4 (based on Eclipse) only runs on Windows; V5 adds Linux.  MPLAB-X has beta downloads for Windows, Linux, and Mac).

NetBeans is primarily known for an excellent GUI builder, which typically isn’t important in embedded development.  I don’t know of any other companies using it for embedded development (or non-Java programming).  Even in the Java world, it’s been a distant second to Eclipse.

Eclipse has been used for non-Java programming (e.g. the C Development Tools or CDT) and embedded programming for a long time, and has many companies supporting it.  So Eclipse should develop a lot faster than NetBeans, and has the advantage of many more plugins.  Plus, Eclipse is run by an independent foundation, not by a company (Oracle) that likes to get paid.

Microchip is not very supportive of open source (unlike most ARM MCU companies).  On the good side, the PIC32 compiler lite version does not have any code size limitations; instead, Microchip removed optimization support.

Microchip is also a good source of low pin count chips, and is one of the few companies still selling MCUs in easy to prototype plastic DIP packages.  For example, you can get a 16-bit dspPIC33F with a CAN controller in 28 pin SOIC, QFN, and DIP packages.

I find Microchip’s mTouch Metal over Capacitor technology interesting: it allows capacitive sensing of metal buttons.

Overall my original post on buying surplus industrial automation equipment is still on the mark.  I won’t repeat it again this year; instead, here are some comments based on 3 years of monitoring eBay and adding to my collection.

In Silicon Valley there are only two decent electronic surplus stores: Excess Solutions and Advanced Component Electronics.  There hasn’t been a good local source for mechanical surplus since Triangle Research closed its doors.

On the web, PLCCenter has a great selection, is great for getting an idea of what stuff costs new, but has premium pricing (except for some on-sale items).

eBay is still the best source, but you need to be patient and know what equipment is worth.  In general, I’m willing to pay 10-20% of the original cost, but many eBay sellers try to get 50%, and a few even ask for more than 100%.  In general, “Buy It Now” means “I think my junk is worth a lot”.  Availability is very spotty; some months there’s a lot of interesting stuff, some months there is nothing.

Also, be sure to check condition and return policies.  Many eBay sellers do not have the ability, equipment, or inclination to test industrial equipment, so if it says “as-is”, don’t pay a lot.  Most of the industrial equipment I’ve bought has worked, but I’ve bought a number of AMC and Elmo drives that don’t want to communicate (since the lights blink, I haven’t given up yet; I haven’t had time for extensive troubleshooting).

Don’t forget new equipment; many vendors (including Siemens and Panasonic) have offered somewhat-affordable starter packages including equipment and software (e.g. PLC and programming software).  Some new PLCs are so inexpensive you don’t even need a starter kit: for example, Automation Direct’s Click PLC starts at $69 and the software is free.

Comments on specific equipment:

• Last time I checked, it appears the Cognex Insight smart camera software is now a free download (after registration).  But I recommend verifying this before buying an Insight camera (which will probably cost >$100).
• DVT smart cameras are still often available on eBay, with pricing ranging from $50 (Legend 510 bought at the right time) to $500 or more (color model such as the 542C).
• Galil motion controllers availability is good, with a wide range of pricing (there are many unrealistic sellers).  USB and Ethernet models are more expensive, although if you’re lucky you can buy one for under $250.
• CANOpen interfaces from Kvaser and Ixxat are frequently available for $50-$150.  I’d recommend getting a used Kvaser or Ixxat instead of a new interface from someone else (which will be at least $100 anyway) because they have the best software support.
• Copley CANOpen servo drives are available fairly often; a reasonable price for an Accelnet is $50-$120; the Xenus is more expensive (>$150).  The Accelnets are my favorite servo drive.  I avoid the older models (800-xxxx)  because I can’t find any documentation for them.
• Elmo CANOpen servo drives are frequently available.
• Ethernet Powerlink drives and EtherCAT drives are occasionally available , but the prices typically aren’t reasonable.
• MEI controllers are often available, at a wide price range, but I’ve never seen the software included.  If you don’t have MEI software, don’t buy the board.
• Panasonic PLC’s are frequently available, but in general I think the asking prices are too high.  At least Panasonic now provides a code-sized limited (but still quite useful) free version of FPWin Pro 6.
• Opto 22 I/O controllers, such as the B3000 and LCSX, are frequently available, often at reasonable prices ($50 and up).  Opto 22 PACs are rare and expensive, especially the current models.  Opto 22 I/O module availability is good.
• Wago 750 and Beckhoff K-bus availability is good, and, if you’re patient, you can get them at a reasonable price.
  • The most popular couplers are for DeviceNet, CANOpen ($25-$75), Profibus, and Ethernet (>$100 for 750-842); I’ve also seen Interbus, serial, and EtherCAT.
  • Digital input and output modules are the most common, and cheapest.
  • Analog modules are less common, and more expensive, but if you’re patient, you can get one for <$50.
  • Specialty modules, such as encoder interfaces and stepper drivers, are the least common and most expensive.

I love the Pen Addict’s slogan: There are worse addictions…..right?

I’m not a connector addict, although I do like trying out new connectors.  Partly it’s because I haven’t found the ideal connector system (or systems; I often want some variety so that the same connector type isn’t used for a variety of incompatible uses, and thus you have to be careful where you plug a connector in).

But I still enjoy receiving the occasional Mouser order with some new connectors.  So along with an order for some MDR connectors for my Copley Accelnets, I included connectors I haven’t tried such as:

• Kycon USB B high retention force connector.  The big feature: minimum removal force is increased from 10N (standard USB) to 15N.  I like them; USB plugs come out too easily, but this connector makes it a lot harder for a USB cable to become accidentally unplugged.
• Amphenol USB A locking connector.  The big feature: the connector has a locking tab that grabs onto the little square holes on a USB A-type plug.  That’s even better than the Kycon: it takes over 95N to separate the plug from the jack without unlocking.
• TE/AMP MTE connector.  Nice, affordable IDC connectors, except you need really expensive tooling to use them easily.
• Molex Micro-Fit Jr 3.0mm BMI.  I wanted to check out the blind mate version of the Micro-Fit; I’m still not a Micro-Fit fan.
• Phoenix PST 1.3/8-LV-5.0 header with shroud.  The shroud provides polarization.  The Phoenix PST headers and PT terminal block plugs are a very affordable removable terminal block system.
  • One gotcha: you have to use the shrouded headers with the PT 2.5 series (e.g. PT 2.5/8-PVH-5.0) not the 1.5 series (e.g. PT 1.5/8-PVH-5.0).
• Phoenix ST-Combi connector and ST-Twin terminal block.  I’m looking at using these for DC power distribution.

Autodesk just released the beta version of the 123D 3D mechanical CAD program.  It’s meant for hobbyists, but Autodesk surprised me by including both STEP file import and export.  (Free or low cost commercial CAD programs almost always don’t include free STEP file export).

123D is the standalone version of Inventor Fusion, so it is a direct modeler (not a history based like SolidWorks or Alibre).  So put together free, easier to use (direct modeling), and STEP file import/export, and it should work great for creating 3D PCB models.  There could be some problems, such as assembly limitations (such as a low maximum number of parts), or the EULA (so far the 123D End User License Agreement appears to be the standard Autodesk one, with no mentions of restrictions on commercial use).

I haven’t been able to check out 123D’s PCB prowess yet because I haven’t been able to get it to start successfully.  I’ll give it another try in a while.

Pretty funny post over at Paul Rako’s Anablog on pranks, starring analog chip designers.

Fluke 196 with Pelican Case

Why do I have an oscilloscope?  The real answer is that scopes are cool, and many years ago, I couldn’t resist when Fry’s had Fluke Scopemeters on sale — at 50% off!  So I own a 100MHz dual trace Fluke 196 Scopemeter.  Later I bought the yellow the Pelican case for it; the two are a great combination.

Since software ties everything together, I’m also the “systems” guy, and thus I should be able to troubleshoot the entire machine.  I do use my multi-meter much more than my scope, but the oscilloscope is essential when troubleshooting encoders, hall sensors, and the occasional electrical glitch which won’t show up on a DMM.

I’ve used other scopes, such as the Tek THS720 handheld, the Tek TDS 210 desktop, Tek analog scopes, and a Heathkit analog scope.  Recently, I participated in a hands-on demo of the new Rhode and Schwartz RTO1014 1GHZ oscilloscope.  It’s quite impressive, even intimidating at first, with all the buttons and things it can do.  Fortunately, such high powered scopes aren’t needed for typical factory troubleshooting; a dual channel, 20-100MHz real time digital does fine most of the time.

There is uncommon feature that’s really handy: isolated channels (each channel’s ground is isolated from the others).  With a typical dual channel scope such as the TDS 210, I can only view one differential encoder signal (channel 1 probe on A+ signal, channel 2 on A- signal, display mode set to combine channels).  But with a dual isolated channels, I can view two differential signals (channel 1 probe on A+, channel 1 ground on A-, channel 2 probe on B+, channel 2 ground on B-).

Hand-held scopes, such as the Fluke 196 and Tek THS 720, typically have isolated channels, along with ruggedness, battery power, small size, and a hefty price tag.  However, a 4 channel desktop scope is often cheaper than a 2 channel isolated channel scope.

I once spent a lot of extra time because I was too enamored with isolated channels.  The system had a servo motor with the differential encoder output split, with one set of signals going to a motion controller and the other set going to a custom board.  The motion controller was counting correctly, but the custom board wasn’t.

I set up my Fluke 196 to look at the differential signals.  The B+/B- signal did look smaller (less voltage swing) than the A+/A- signal, but it had to be OK because the motion controller was picking it up.  So I started swapping out components — and kept getting the same problem.

I figured it out when I looked at each signal (A+, A-, B+, B-) individually; the B- signal was dead (because of a broken wire in the cable from the motor).  The motion controller worked because it was less sensitive, managing to count the smaller transitions.  My lesson learned: check everything, and don’t make unsupported assumptions.