Sardines Seven Miles High

Being in the electronics industry means working on cool projects with cool people, but it also means other things. Like plane travel. I love flying. Not necessarily in an airplane though. I mean, I do prefer to be in an airplane when I'm flying. I'm more likely to have a subsequent flight if I first actually fly in an airplane rather than not in one. It's just these "big" commercial airplanes that we get stuffed into these days. Most of the complaints I read about relative to commercial flying have to do with the TSA or being stuck on a runway for six hours with overflowing toilets, but I haven't had those issues.

In point of fact, I don't think I've run into a TSA person that hasn't been polite. Especially in Portland. Still, even if they're nice people, I really don't like the idea of a choice between being nuked or groped. For the record, I chose to be nuked when I had to make the choice. I'm sure the government sanctioned groper wouldn't like it any more than I would, so I did us both a favor and stepped into the radiation chamber. I don't feel any worse for the rays. Maybe they were nice rays.

So, I don't have any complaints about the TSA. The crowds sometimes get me down, but all things considered, they aren't all that bad. What does get me is the straight jackets that they call seats these days. I'm in a motel in Milwaukee right now. I'll be heading home tomorrow. First in a mosquito plane to Chicago and then, probably, a 737 to Portland. I like the 737 in concept. It's a good plane. I just like being able to breath a little. It's natural to not have any room in the micro plane that I'll take to Chicago. It's not much bigger than my truck and will have twenty people crammed in it. You expect to be folded like a pretzel and spam crammed into one of those.

But a 737 is a big airplane. I can stand up in it and I'm not short. It's not like a little micro car. It's like my pick up truck (just not like it with 20 people in it). In the olden days, I preferred window seats for the view. Then I went for the isle seats for easier access in and out. Never the middle seat. Now, though, they keep taking leg room out so I'm not so sure. The seats get smaller every time I get on a plane.

If I take the window, I'm stuck for the duration of the flight with my knees just about in my face. Leg room in the isle seat is narrower so when I put my laptop bag down there I can't even wedge my feet under it to steel an extra few inches. Now that they charge for checked baggage, everyone brings their luggage as carry on and there isn't room to put both my suitcase and my laptop up in the overheads. I think they have the sky marshals throw you out the back window if you try to put both of your carry on's up top.

And so it goes. I'm just going to take whatever random seat I get and hope for the best. And I'll feel like a king if they grant me the supreme luxury of an entire 12 ounce can of warm soda pop.

Duane Benson
Curse you Red Baron!

Zzzzzzzap!!! Static be Bad

Engineers these days have so many issues to worry about just in component handling alone:

  • Do my parts need baking to get the moisture out before reflow soldering?
  • Are my parts in stock?
  • Are my parts real or are they counterfeit or secretly remanufacturerd?
  • Are my parts really lead free?
  • Are my passive components small enough to make it out of the holes in my salt shaker so I can put them on the PCB?
  • Are my parts too small form my manufacturer to handle?
  • Are my parts too complex for my manufacturer to assemble?
  • Have my parts been zapped by static electricity either before or after assembly?

Static electricity is really something that no engineer should have to worry about these days. We know how it gets created. We know how to artificially create it and we know how to guard against it. There's really no excuse - especially from those that an engineer entrusts to build his or her designs.

Tesla_colorado_adjusted 500

People can carry around a static charge anywhere from several thousand volts to more than ten thousand volts; just by walking around. Joe Volta would be proud. Touching an electronic component or assembly the wrong way at the wrong time can discharge much of that through the electronics. Yes, most chips are better able to handle static electricity than the old 4000 series CMOS that could get zapped just by being looked at harshly, but pretty much any active component is susceptible to static damage to some degree. What makes it so Anti stat shoesinsidious is that the damage may be done in handling or in assembly but might not show up until the unit fails in the field.

The whole world knows how to keep electronics safe (that's an exaggeration, but at least most people in the Industry know how), and the whole industry understands the risks, so why would anti-static handling or packaging be an extra cost option? If it's you're own stuff, then fine. It's up to you. But someone you're paying? I don't get it.

Take a close look at the picture on the right. If you ever get a tour through Screaming Circuits, you'll see a lot of this. The floor is conductive. The bright green straps on the shoes are not a fashion statement. They're grounding straps. The blue jacket is conductive. Parts and PCBs are protected from static through these means and others all the way in and all the way back out to the customer. It's the right thing to do and the healthy way to do it and it doesn't cost extra. It shouldn't cost extra. Follow good static mitigation procedures yourself and make sure that whomever is assembling your parts does the same. That's my two cents worth.

Duane Benson
Frankenstein was grounded through his neck bolts, so he's okay.


Thanksgiving - Real or Manufactured?

A decade or so ago, PC (political correctness) was the phenomena of the day. People talked about it. People implemented it. People balked at it. The end result was good, but the period was kind of a mess as some people went too far, some refused and everything in between. Today, I think it's "AHC" or Alleged Historical Accuracy.

I say "alleged" because most of these things happened way before anyone alive today was around, and back when record keeping was spotty at best and often as much fiction as fact. In the Soviet Union, they did a lot of revisionist history. This isn't that, but it's along the same lines. With AHC, sometimes 640px-Embarkation_of_the_Pilgrimsthere is a lot of truth, sometimes not, and, again, everything in between. The latest victim of AHC is Thanksgiving.

Way back in grade school (those of us in the US) were taught that Thanksgiving originated with the pilgrims and was a celebration of a good harvest and friendship with the native population or something like that. Hollywood tells us that a pilgrim is a friend of John Wayne's, but that's completely unrelated. I've recently read that Lincoln started Thanksgiving, turkeys weren't part of the original one, the Spanish started thanksgiving and a bunch of other newly reveled possible facts.

Personally, I don't think it matters. A lot of things change over history with original meaning being obscured in the fog of the past. Bleach was once used for whitening teeth. Now we know that using it for that will destroy your teeth so we don't do it any more. Listerine has been used as a floor cleaner but now we put it our mouths. The Listerine, not the floor. (I hope)

What matters most to us though is what we use it for now. History does have its place and accuracy in history is very important, but unless something is inherently bad, there's no need to call out something as wrong just because its used differently now or our original view of its start has changed. Personally, I'm thankful for a great job doing work I'm proud of and for family and friends. There's lot's of other stuff too, but this is enough for the purposes of this post. I'd write more but I'm going go buy groceries and then write some test software for a robot board.

Duane Benson
And I'm thankful that most people don't like the nice crispy turkey wings as I do

40 Years of 4004

I'm assuming eight pages excerpted out of 142 qualifies as fair use. I had forgotten that I had this thing buried in a box in my garage. I have a lot of old junk hidden in boxes out there, but this one piece seems most appropriate today.

  4004 005 4004 006 4004 007 4004 008

4004 009 4004 011 4004 012 4004 013













This user's manual covers the 4004 and the chip set that went along with it. It also has some pretty detailed information about a couple of computers based on the 4004; such as the SIM4-03, MCB4-20 and Intellec 4. I didn't get this new. I found it in a garage sale back in the early 80's. I wish the unit had been there too.

Duane Benson
4 bit data bus, anyone?


If there was a lot of twittering going on, I think I'd call it "flutter." I could call it "a bunch of Twitter tweets", but that's too long and awkward, so I'm good with flutter. Probably because it's short and rhymes with clutter. If there's really a lot, then we could call it flutter clutter.

Regardless, I'm still in my quest to determine if Twitter really does have a use that matches up with something I might need or find useful. I'll just take a few examples. What I'm finding is, in addition to the "I ate a cheeto" noise, there seems to be useful information. I regularly pass through a fair number of websites, but there are more that I would like to keep up on.

If the website owner does a good job, I can keep posted on their doings and I can know when I need to pop over for more detail. Adafruit is a good example of that. I'm not currently in the market for anything they sell, but they are one of the most influential members of the open source hardware community. By following them on Twitter, I can just glance at their announcements quickly and quickly jump over if I want more detail. That works pretty good for keeping up with the OSHW folks. I have a number others that I follow for similar purposes..

I also like to keep up with the mood and mindset of the engineering community. I read the trade magazines (or their websites) but there is more to it than that. I don't follow many periodicals because the volume of tweets tends to be too high. I have few (SilconFarmer, Chris Gammel, Mighty Ohm and freaklabs) that I follow specifically for that purpose. That's useful.

MaxMaxfield AKA Max the Magnificent always has interesting things to say. Some just his own thoughts and some teasers for interesting articles he's written over on the eeTimes website. And he posts just about the right amount. Enough to be worth following but not so much as to become noise. Mike Buetow over at Circuits Assembly magazine does a very good job of keeping me informed about what's going on in the EMS industry. Very valuable.

Okay, so that's not everyone I follow, but it's three different types of Twitter streams that I follow and find useful. I think that means that whether I like it or not, I do seem to be finding use in all of the flutter clutter. I won't call myself completely sold yet, or even a Twitter fan, but I may be getting there. I still do my best to avoid the "Cheerios are good" crowd.

That's three uses. Any other good uses for it in the technical community that I've missed?

Duane Benson

So Long Old Friend

Just watching the final shuttle launch and pondering a few questions.

A significant number of innovations came out of the Mercury, Gemini and Apollo programs and filtered down to public life. Some were in materials, some were in electronics, some in software algorithms  and some in other technology areas. It was pretty much all new back then. When the shuttle was first being developed back in the 1970's, innovation in materials and other areas came about as well, though it did use a fair amount of recycled technology in the beginning.

But since that time, have there been any major breakthroughs directly from the shuttle to filter down? Though it never lived up to the "one launch a week" billing, it did, in a sense, become the space "truck." Sort of an old pick-up truck. Not much new. The occasional upgrade. The occasional breakdown. But mostly just there hauling stuff around.

When the next manned launch vehicle comes out, will it deliver a wealth of innovation as did the first decade of manned space flight? Or will it be designed with primarily off-the shelf or near off-the-shelf technology?

In the 1960's, private industry benefited greatly from the research that went on in the space program. I suspect that the next time around, whether it's a NASA design or a commercial design, it will be the other way around and the space vehicle will benefit from research paid for by commercial activities.

Duane Benson
Thanks for all the fish

Loopy Ground Loops

A while back, I posed a question about using flood fill (AKA copper pours). I've been reading a lot about ground loops lately which brought me back to that original question.

LED scroll ground plane Some people suggest segmenting your ground plane between analog and digital sections. Some people suggest segmenting the ground plane for individual critical ground return paths. The follow on to my original question is: On non-exotic designs does segmenting ground planes really help? There's actually two questions, with the second being: At what clock speed does it make sense to start worrying about issues caused by ground return paths / ground loops? There are probably more questions. Those are just the two rattling around in my head at the moment.

Interestingly, though, when I wrote the original post, there didn't seem to be a clear "most common" between pour and no pour PCBs. Today, I'd have to say that the majority of designs we see here at Screaming Circuits do use flood-fill ground planes, either internal or external.

Duane Benson
You can solve ground and noise problems by just not hooking up power

Bouncing BGAs

I dropped my cell phone on the pavement the other day. That's bad enough, but in my instinctive attempt to catch it, I actually hit it and increased it's downward velocity. Luckily, everything still works. The odd thing is that I just assumed that it would still work. No real questions or doubts on that thought.

That realization got me thinking. (it happens now and then) What other devices do I have that I automatically expect to survive a drop onto concrete? I have a carpenter's hammer. I expect that to survive a drop intact. I would not expect my camera to survive such a drop intact, and have empirically verified that fact. A little car GPS? Probably not. Laptop; uh... no.

I'm sure there are some other devices that would easily survive. I just can't think of any off the top of my head. I suspect that there are a lot of factors that go into making cell phones survivable. The case, the overall mass, the quality of solder joints.

Along those lines, some folks use an underfill glueish type substance to hold their BGAs more securely. Some designers use pick and placeable solid underfil. Some just rely on extra good soldering and some leave it to luck. Of course, not all BGA installations require much shock resistance. How do you secure your parts when shock or vibration are serious concerns?

Duane Benson
Quick, where's Henry? I need an inductor.

Hi Ho. Hi Ho. It's off to Scone I go

I found this video over on the adafruit blog. Asimo, by Honda, is cool. Mars rovers, by JPL, are cool. Packbots, by iRobot, are cool. But, for robots to really take off, they need to be able to run down to McDonald's and buy some Big Macs or saunter on down to the Latte shop and pick me up a 16 oz non-fat Latte while I stay at my desk and keep working. Maybe hop out of the car and get one while I drive around because I can't find a parking spot. Donuts would be good too.

Now, that is a real robot. The only problem with the bot in this picture is that it needs a place to put the drink. Scones can be pretty good, but they tend to be kind of dry for my tastes without a drink to go with them.

Duane Benson
Watson - come here! Find Juan Valdez and ask him where I can get some coffee.

Twitter, What is it Good For? Absolutely 555contest

I follow a few people on Twitter. A few people follow me on Twitter.

A number of web sites have engaged their readers in debates about the usefulness of Twitter (and other social media) to engineers. In general, these debates are talking about hardware engineers. A lot of software engineers pretty much live on the Internet and will embrace or invent any new thing.

The overwhelming majority of the responses that I've read put Twitter in the class of "a waste of time." Not everyone feels that way, but there's quite a few who do.  I'm still in study mode. I can see how it can take up a lot of time if you don't exercise some self control and it has a weird partial-voyeur aspect.

If I'm following, person A and person B, I'll see any conversation they are having. Most discussions are undertaken with that in mind, but some start to lean toward the personal side. Now, if person C gets in the conversation with one or both of A and B, and I'm not following C, I end up 723px-NE555_Bloc_Diagram.svg seeing part of the conversation. It's a bit like listening to someone talk on the phone and hearing only their side. It's odd.

It can lead to interesting activity though. Recently, one tweeter, Jeri ( suggested a design contest centered around the old stalwart 555 timer. Chris ( picked up the ball with her and In about three days, just over Twitter, they organized it, other tweeters chimed in, sponsors offered prize money and they've set up a website for it. Fascinating.

If you're on Twitter, search for "555contest" to see the conversation in action. In any case, if you're a fan of the now 368 year old 555 timer, you might want to dig into the recesses of your brain for entry ideas. You can also follow Screaming Circuits on Twitter at "" and see for yourself if it's useful or too loaded with mindless drivel.

Duane Benson
Huh! Yeah!