Intergalactic Geek Pride Day Quiz

There was a time when "Geek" was far from a badge of honor. Jr. High School (AKA middle school) was developed specifically for the purpose of making geeks miserable. We were told that lockers were  designed for holding books, lunches jackets, but in reality, the secret anti-geek coalition had lockers installed so geeks could be stuffed inside of them, or could have the doors slammed in their faces.

But, then something happened. While the world wasn't looking, a geek became the richest man in the world. Pro-nerd and pro-geek movies became popular. It became cool to claim to be a geek or a nerd. The problem is that there's a big difference between claiming the title "geek" and being given the title "geek."

Well, May 25th is Geek Pride Day. In honor of Intergalactic Geek Pride Day, I've put together a little quiz on the subject.

Questions:

  1. Is it better to be considered a nerd, a geek or both?
  2. What's the difference between a nerd and a geek?
  3. Does the outside world know the difference between "nerd" and "geek" and thus does it matter which one you're called?
  4. If you've never actually been called a geek, but claim to be a geek anyway, are you really a geek?
  5. If a geek talks in the woods, but there's no one there to hear, did the geek actually speak?
  6. If you can explain what you do for a living (or hobby) to a random stranger and have more than about one in fifty understand, can you still claim to be a geek?
  7. If you don't have enough cables laying around the houses to connect just about any two pieces of computer / electronic equipment together, can you really claim to be a geek?
  8. If you can't assemble a spare PC from parts you have around the house in about an hour, can you still claim to be a geek?
  9. If you can't count in more than one base, can you still claim to be a geek?
  10. If you don't love songs by Tom Lehrer, can you still call yourself a geek? (If you don't know who he is, quick: Youtube)

 Bonus question:

  1.  Tesla or Edison?

Answers:

If you're a true geek, you already know the answers so I don't need to list them.

Duane Benson
The best revenge is not violence or deviousness
The best revenge is to be happier
...and to build robots for world domination

 

Canada's Singing Astronaut

If you're going to exit, you may as well exit in style and I can't think of a better example than Commander Chris Hadfield's "good by" from the International Space Station on Monday (May 13). Thank you, Astronaut Hadfield.

Since this is my  electronics blog, I've got to tie it into electronics design and assembly, so, like um... If you're building electronics for space, you might need to better insulate your PCB traces or put wider gaps in because otherwise you might get arcs and stuff. And be sure to shave your tin whiskers.

Duane Benson
Please sir. May I have some more

Unsolicited

I have a question for you. When is the last time that you responded to an unsolicited email? It's been a very long time for me. However, I just did open up and read an unsolicited email that actually seems somewhat relevant to me. The specific subject was an offer to be a guest blogger here on blog.screamingcircuits.com. I don't know that I'll take them up on the offer. It kind of depends on what they might want to write about.

But I did jump over to their website: www.circuitspecialists.com. I've never done business with them, but they do have some interesting products and they started in a garage in 1971. Anyone who started in a garage 40+ years ago and is still around must be doing something right. Their site looks like it's more or less focused on test & measurement, prototyping, robotics and other things electronic. (I think I've heard the term "prototyping" someplace...).

What first caught my eye as relevant was their section on digital panel meters. Why would that catch my eye, you might ask? (Or you might not) The first panel meter I looked at is an "independent power supply version." Ah, the plot thickens. Just last weekend, I exploded a power supply in a robot I'm building. It didn't actually explode, but it certainly did release smoke and stopped releasing electrons at about the same time. Smoke for electrons is not  a fair trade as far as I'm concerned.

I was putting a digital Ammeter on the main power line and couldn't remember if it the meter was designed for high side or low side. Poof! I empirically determined that it was designed for low side. I should have known better because it drew power from the robot power supply without any isolation.

If my meter had an isolated or independent power supply, then I could probably have put it on the high side. Oh well. It wasn't the first time I've traded smoke for electrons, nor will it likely be the last.

Duane Benson
rhythm characterized by regular recurrence of a systematic arrangement of basic patterns in larger figures

The ESD Habbit, or an Unexpected Shock.

Excitement is building here. In a little over two weeks from today, The Hobbit movie will be released to theaters. I'm sure everyone reading here knows the story, but in case you don't I'll spoil it for you.

It's a story about Biblio who is, according to Spock, the bravest little hobbit of them all (google that if you don't get the reference. You'll be glad you did). Biblio is minding his own open source robotics business when the Wizard of Menlo Park (in CA, not NJ) invites 12 MCU designers over for a meal and discussion about the merits of hardware peripherals vs. bit-banged peripherals. The MCU guys convince Biblio to go with them to The Lonely Mountain Chip Fab and help them kill a terrible ESD Spike problem. Actually, it's the Wizard that convinces the MCU guys that Biblio could help. The next day the MCU folks left early and Biblio ran out to catch up with them without even an ESD smock.

The ESD problem came from the North because it's more humid up North and that tends to dissipate ESD. Our Terrible Spike didn't like the idea of being dissipated without having first destroyed a few gold interconnect wires. The MCU guys need those gold interconnects to remain intact, so they brought a secret encryption key and enlisted help from the technician Biblio.

First though, they had to get past the TO-92 packaged parts that wanted to squash them into jelly or tacky flux. Fortunately, despite the bumbling of technician Biblio, the Wizard bought solder with no-clean flux which made the TO-92 parts stop moving once applied. After the TO-92 parts stopped working in daylight, they made a brief stop to inspect the last Homely Chip Fab in the Silicon Valley and see where the light sensitivity came from.

Passing over the Siskiyou Mountains on the way to Oregon and The Lonely Mountain Chip Fab, it started raining so they went into a cave and ate porc for dinner. Biblio ate so much that he fell asleep in the corner behind a chair where no one could see him and his buttons popped off. The missing buttons didn't bother him too much because those ones had a de-bounce problem anyway. Luckily, they weren't Grayhill switches or they would have hates Biblio forever, even if he used an ancient gold Tolkien-ring network to bypass more porcs.

Biblio wasn't the most skilled technician and he caught his pine cones on fire while trying to solder new switches into place, but the wizard was able to re-layout the board using Eagle CAD and an FPGA that could take many forms and would satisfactorily control the machinery and bears at the local honey production facility. But the FPGA brought them all into the murky world of Verilog and VHDL. That would have been fine except that the search engine spiders hadn't crawled the eleven Wikipedia pages they needed to properly map out the clock routing.

The MCU guys got hungry and wouldn't wait for Biblio to come back with pi so they rushed in causing so much in rush current that the lights went out with a snap. After eleven clock cycles in his new hall-effect switch, Biblio knew that the de-bounce problem would be gone except when he plugged the barrel jack into his Apple computer. But with no static guards to wine too, he had no choice but to use the Apple barrel jacks to get power to MCUs and switch open the flip flop made from a streaming-transistor logic gate.

Annoyingly, they split the story in two and the movie will end at this point. We'll have to wait another year to see if Silicon Oakensubstrate is robust enough to kill the terrible ESD spike and pass final QC.

Duane Benson
One oven to reflow them all

Cool Customer Application

It's not all that often that we get to see or can talk about just what is done with the boards we build at Screaming Circuits. In most cases, it's a proprietary product or some government thing. But, recently we built some boards for NTH SYNTH. They have a successful Kickstarter project to produce a music synthesizer. They describe it as: "It is fun to use, sonically-rich, and hackable by design." Go check it out.

Nthsynth-small-007

[This image is from their website] I had wanted to take some photos for them of their PC boards being assembled on our SMT machines, but the boards ended up being built on one of our night shifts and I missed the chance.

Duane Benson
They're the people out there turnin' music into gold
But hopefully makin' more than Jim Bass' two-fifty for an hour

 

Retrospective

The other day, I needed just a few things at the grocery store which, given the small town I'm in, should have been a quick no-stress fifteen minutes. But, some kids were sitting in the middle of the first intersection I came to and didn't seem to want to move out of the way of my five thousand pounds of rolling danger. Traffic at another intersection was backed up due to a train. On the next block, I had to follow someone, likely looking for an address, at about ten miles per hour. Then there were pedestrians crossing the street far slower then human body mechanics are designed for. In the store, it seemed like every isle I tried to go down was blocked by carts or people. The "short line" at check out turned out to be short because a customer and checker were having payment issues. The drive home was much like the drive in. In short, there was nothing short about the trip. Nor was there anything low-stress about it.

But this is a blog about electronics stuff. It's not a shopping blog or a driving blog. The point is, that trip reminded me of projects I've been involved in years ago. Someone changes a spec after that part of the design is complete. The only version of a key component on the approved vendor list has a 12 week lead time. It's Friday, at 4:00pm, the board files have to be shipped off by five, but there's still several hours of double checking left to do. While placing the prototype parts order, you keep getting distracted by loud talking in the background.

Ugh. Not only is such a thing blood pressure raising, but it also can lead directly to problems any of us would never dream of letting out the door. Like these here:

Too little time can cause problems. So can too much stress and distraction. There's not always a good solution, but anything to reduce stress and agravation while doing final checks is probably a good thing.

Duane Benson
Is there "lab rage" like there's "road rage"?

To Mod or Not to Mod? That is The Question

Many years ago, I was a product manager at a business-consumer electronics company developing some pretty leading edge display equipment. Prototyping back then was a long and painful process. A PC board might take a month or two to arrive from fabrication. Parts had to be sourced by digging through massive catalogs and then hoping that what you needed would be on the companies approved vendor list. The whole process was a bear.

Well, the soldering up part wasn't always so bad - unless you were the poor soul tasked with wire-wrapping or hand soldering the prototype.

Based on how difficult and expensive a board spin was back then, common practice was to just mod up the boards, even in production. Any given PCB might have a dozen or more cuts and mod wires. Those changes might not make it into the PCB for months. These days, though, you can get board fabbed Mod wireovernight, your parts delivered over night, and when you have all of those parts and PCBs, you can get them assembled overnight. I suspect that increase in speed is the major reason mod wires seem to be nearing extinction these days. (note that Screaming Circuits didn't build the board in this picture. It's from my personal collection)

It may not seem cheap to pay to have someone re-spin a board so speedily; especially when set next to hand soldering. But when compared to the cost of idle engineers waiting for the next rev, the cost of adding mods, the reduced reliability from having mods and the additional manufacturing time caused by modding a board; today's quick-turn parts, fab and assembly options can end up saving gobs of time and money in the long run.

Duane Benson
There are more wires in heaven and earth, Horatio, Than are soldered on your pc board.

"Shrinky Dink"

I had some "Shrinky Dinks" when I was a kid. Amazingly you can still buy them. You can also use that concept in your prototyping. I did that recently. I have a robot board design that I'd like to shrink about in half and add in a LiPoly charger chip. Most of the design came from something I had built previously, but the charger chip was new to me as was the compression needed to meet my size goals. Sadly, you can't just put your PCB in the oven and have it shrink like a Shrinky Dink. Maybe if you could put stretchy copper traces on it so they wouldn't peel of while the substrate shrinks...

The charger comes in both DFN-10 and MSOP-10 packages and the MCU comes in SOIC and QFN packages. The QFN is the 44 pin version while the SOIC is the 28 pin version of the chip. Same core. Just more I/O.

LBDC Li LBDCmini pRather than test my ability to shrink and the use of the LiPoly charger at the same time, I added it into the original design without changing the size. There's much more room for probing or even for adding test points if I needed them. Once that design checked out okay (which it did), I just went into the schematic editor, changed the SOIC to the QFN package, the MSOP to the DFN and most of the passives to 0402 packages. I really didn't have to make any changes to the schematic.

That almost worked perfectly. The 28 pin MCU doesn't come in a variant with a QFN package, so I couldn't just change the package type in the schematic editor. I had to delete the SOIC version, place and wire in the 44 pin QFN variant. I made a few other changes too. I added in a QFN packaged RS232 driver and a hard power switch. In the original, I had envisioned a soft power switch but I changed my mind. I also had to modify the library parts to make sure that the solder paste layer on the QFN and DFN parts fit our guidelines. Lastly, I removed some LEDs that I only had on the board for debugging purposes.

The most important two considerations were watching out for physical part interference and getting the paste layer correct on the QFN/DFN parts.

Duane Benson
It's the size of a small walnut

QFN Solder Paste Layer

LBDCminiI've got the fab order placed with Sunstone.com for my next demo project. The little board is represented here at pretty close to actual size on screen - provided you have a 22" monitor set at 1680 pixel horizontal resolution. Give that, you might want to click on it to pop up a bigger representation of it. That makes it about 4 X life size.

When you do that, take note of the QFN / DFN parts: The processor in the middle, the LiPoly battery charger right between the upper two mounting holes and the RS232 driver in the lower left. I've followed my paste layer advice and segmented the paste stencil layer to reduce the chance for float or major voids.

I found a footprint in the library for the big processor in the middle. I just had to modify the paste layer, as shown here. I made the footprint for the charger and RS232 chips from scratch. Neither had anything close enough in the library.

The DFN has a slightly different approach to segmenting the stencil layer. Little squares like I used on the other two chips work just as well, but this is effective as well.

Another thing to take note of is the markation on the LEDs. The original footprint for the 0402 LEDs does have a polarity mark, but it's one of the types that can easily be misinterpreted or can be difficult to see. The diode symbol put down in silk screen removes any possibility of ambiguity.

Duane Benson
I'm happy I live in a split level head.

 

Particle Update

I've been ignoring my Geiger counter for a while now, but I picked it back up and made some progress again. For some reason, I just wasn't getting the 555 based HV power supply to generate a high enough voltage. In frustration, I bypassed the 555 and fed a PWM signal in from a microcontroller board that PIC SMT geigerI have laying around.

That fixed the problem. I still don't know why I wasn't able to the the 555 doing what it was supposed to do. I'll have to spend some more time on that some other day, but for now, I've prototyped it out and I'm happily detecting particles. I whipped out the new layout and will send off to Sunstone.com com for another set of PCBs.

I've also replaced the Atmel chip with a PIC. I don't have anything against Atmel. I'm just more familiar with PICs. Once I've built a few of these, I'll change to really small packages - QFNs or BGAs for the chips - to make the board a little more fitting with our assembly capabilities. The SOIC chips are fine, but our machines don't even come close to breaking a sweat with things that big.

Duane Benson
We treat agoraphobia for PC boards