How Not To Build A Tablet PC

Just came across this video by Dave of EEVBlog (see below). Now, granted, a little Dave goes a long way — a lot of his videos consist of him ranting about how horrible some piece of tech or another is.

Dave’s ranting is 100% justified in this case. Someone custom-built a Windows XP tablet PC, and they seem to have used it as an opportunity to thumb their nose at just about every single electronics rule in the book.

The power supply board (why they would hand-roll one when they’re a commodity item is beyond me) is particularly craptastic. They went to the trouble of making a two-layer board, only to basically not use the second side. They’re also using quite a few through-hole components as surface-mount components. It’s only a matter of time until those solder joints fail and come off the board.

There are many, many other no-nos visible:

  • Cold solder joints throughout;
  • Holding boards in place with double-sided tape;
  • Soldering directly to rechargeable batteries without tabs;
  • Packaging the batteries together with shipping tape;
  • Leaving loose, unused wires in place (at least they put some shipping tape on them as a talisman to ward off electric short demons);
  • Soldering a USB cable to a board, when a USB-to-mini-USB cable would do great;
  • Using at least three different battery packs one battery pack in three pieces;
  • Using a heatsink pad in a halfhearted attempt to couple the heatsink to the case; and
  • Using a heatsink with no provision for airflow. Where’s it going to dump the heat to, guys?

Dave is known for his over-the-top rants — but he gets a pass on this one. This is weapons-grade craptastic construction. (I suspect that either the company has VERY strong micromanagement — and/or they’re using interns with almost no electronics experience.)

Yeah, it’s serial number 11 — so a few glitches are to be expected. But this thing is almost cargo-cult-like in its construction. I’m really surprised that it works. (It won’t, for long.) And this piece of crap was sent to a client. A medical facility, in fact! I wouldn’t have tried to turn this in as a class project. Its construction would be just too embarrassing. I’ve never seen any student projects anywhere near this bad. Not even from freshmen who are learning electronics for the first time. At least they have intelligence and common sense.

(Warning: this video may cause Computer Engineers to lose faith in humanity…)

Posted in Design, DoNotTryThisAtHome, Electronics, Reverse Engineering, Reviews | Leave a comment

The Future Is Now

October 21, 2015.    Welcome To The Future.

So, does it really seem like we’re living in The Future?

Well, no, not really. But then, it wouldn’t. Our experience of time is continuous, so anyone who has been along for the wild ride we’ve experienced since 1985 has had ample time to get used to — and maybe even disappointed by — all of the cool technology that we have today.

  • We don’t yet have real, working Hoverboards — although there are some promising but power-hungry prototypes. Probably the closest thing is the Green Goblin-like multicopter recently making the rounds on YouTube. We’ve solved everything except the battery technology. (Engineers from 1985 would nod sadly.)

  • Nike does seem to have come out with a limited-edition run of Power Laces. This seems plausible to me (meaning, I can think of some possible approaches to making it happen.) It’s probably fragile and expensive as yet, but it seems to work. Easier to just stick with Velcro for now (a dazzling piece of 1960s high-tech spun off from Apollo-era research.)
  • Self-drying clothes still don’t seem to even be on the radar. I guess the umbrella is just a little too practical an invention to be displaced that easily. Especially when you consider that you’d have to carry around a huge supply of energy just in case your clothes needed drying. Physics will be physics, and a dryer mechanism has to have something to eat, after all.
  • Flying cars? No, thanks. Not until we can do something about Driver Ed, or come up with a good autopilot. When I think about driving across town on the Schuylkill, I don’t want to even contemplate the idea of all of these boneheads getting behind the yoke of a flying machine. Plus, there’s the energy costs…
  • … and as for time machines? I don’t think they even can exist — at least, you can’t go back to a prior point in your own timeline and make changes. Think about it: Any time machine is pretty much going to require an electrical engineer or ten — and the very first thing that most EE’s would think of doing with a time machine is to go back and buy poor Ben Franklin a clue that he’s making a terrible mistake with the polarity of electrons:


Since this hasn’t happened, it isn’t going to happen. Therefore, time travel to the past isn’t looking good. But it does make for a great story.


If I were to meet the 1985 version of myself and take him on a tour of The Future, I know he’d be duly impressed. For example:

  • Most of us carry around, without really thinking about it, a device which allows us to nearly instantly tap into all of human knowledge and learn about any given topic, often by simply asking (Google, Siri, or Cortana) about it in plain language. Smartphones would dazzle anyone from 1985 — and when they saw the circuitry involved, you’d be lucky to avoid being accused of witchcraft. Any 2010s-era smartphone would probably be confiscated by the 1985 DoD and put to use doing nuclear simulations — because it would count as a legitimate supercomputer.
  • What makes these magic data devices work? THE INTERNET. Full stop. Here is true magic that even Back To The Future only really hinted at (although their hints do often point in the right direction.) This is not only amazing Future Tech — it’s right up there with the inventions of fire, the wheel, writing, and moveable type. Yeah — ARPANET was around back then, and just starting to evolve into the IPv4 TCP/IP network we know today — but the difference between today’s Internet and that is, as Twain would have put it, like the difference between lightning and a lightning bug.
  • Along with ubiquitous data connectivity, GPS allows us to instantly know our position (at least outdoors) anywhere on the Earth, 24/7. 1985 would understand this technology — it was being developed even back then — but the scope of its use would blow them away.
  • The 3D printing revolution would also amaze folks from 1985. Crude prototypes of similar things probably existed back then, but in 2015, we’re starting to see mainstream consumer companies like Amazon and Walmart start to take interest. We’ll see the $100 desktop replicator — at least for ABS and PLA plastics — yet.
  • The Internet of Things, while admittedly in early infancy, is starting to make its presence known. The recently-offered Amazon Dash Button, for example, makes ordering consumable products literally as easy as the push of a button. You notice you’re running out of paper plates, press the button, wait for the green light, and a couple of days later, a package with the plates shows up. Downside: I now have WAY too many paper plates (and I only pressed it once). These buttons don’t work out so well yet for single guys. Not much use for a button which only gets pressed a couple times a year. Fortunately, there are hacks for that.
  • We have two working rovers on Mars — one of which (Opportunity) has been going for well over a decade now.
  • We have reasonably reliable text-to-speech (which 1985 would have found pretty cool), and reasonably reliable realtime speech recognition (which 1985 would have found amazing.)
  • Our video games would blow away even the most diehard gamer from 1985. People were still regularly playing Atari in 1985. Today, you can get munched by a dragon in beautiful 1920 x 1080p, and capture the footage for posterity.
  • We have social media like Facebook — where even total social recluses like me can keep in touch with all of the awesome people we’ve known (some of whom I even knew back then!)
  • Our President happens to identify as African-American. And this is No Big Deal. It looks very much like our next one will either be Jewish or female. Again, No Big Deal.
  • We have very nearly gotten rid of VHS tapes, and moved to reliable digital technology.
  • CRTs are almost a thing of the past. Flat panels are so ubiquitous that we don’t think twice about them, and stare when we see someone using an older tube display.
  • And last but not least, we even almost have holodeck-like technology.

Now for the tricky part — predicting what the next thirty years will bring! Technology advances exponentially, and we may well be heading towards Kurzweil’s Singularity. Here are a few of my thoughts on what we might see in thirty years. These are educated guesses, but very much guesses. It should be interesting to see which, if any, pan out.

  • Aging: We are able, by the year 2045, to reduce human aging to 50% or less of what it was; the average lifespan in developed countries will exceed 100.
  • Religion: Fundamentalism will give way to deism and/or agnosticism, or at least a more scientifically-aware version of current religions, as many of the wilder claims of mystics (stars falling from the sky etc.) are seen to have no basis in reality.
  • Telework: As the more conservative generation retires, Gen-X and younger supervisors become open to the idea of people working from home. Most “Information Economy” workers can be just as productive, if not more, from home, anyway. For one thing, my home computer is a whole lot more capable than any work computer I’ve ever had.
  • Consciousness: A high-powered supercomputer — like IBM’s Watson — passes the Turing Test around 2020-2025. Personal computing devices do so within five years of that. This leads to all sorts of interesting discussions about consciousness, intelligence, and what it means to be alive.
  • The first cybersentients are created sometime in the 2030s, and proceed to create even smarter ones.

…and that’s when the afterburners will really kick in.

Buckle up. It’s going to be a fun ride.

Posted in Current Events, Digital Citizenship, Mad Science, Nostalgia | Leave a comment

The Parable of the Thermostat

I usually keep religion and politics out of these posts, since learning more about science, math, and engineering can benefit anyone, no matter what his or her political beliefs. However, on occasion, it is important to point out logical fallacies — especially when those espousing the fallacies are running for President — and should know better. Recently, Ben Carson, a neurosurgeon and Republican candidate for President, stated that he believed Darwin got the idea for Natural Selection from Satan.

This is NOT how science works, Mr. Carson. (You’ve given up your right to be called Doctor, in my opinion.) Science works by considering the evidence. It doesn’t matter — at all — what result you want to see. What matters is what results you actually get — and what evidence is actually there, waiting to be measured and quantified.

To explain this difference, and why it matters, I offer a cautionary tale in traditional religious / folk-knowlege anecdotal form. Here, then, is The Parable of the Thermostat.

The Parable of the Thermostat

Once, there were two identical houses, built side by side. Each was constructed in the same manner, from the same materials. 

These houses were bought by a Scientist and a Mystic, respectively.

One day, the weather became cooler. The Scientist consulted her thermometer. “It is getting colder out,” she noted. “The temperature in my house is too cold. I shall build a Thermostat to automatically measure the temperature and connect it to a Furnace, so my house remains comfortable this winter. If my house becomes cold, the Thermostat will sense this and cause the Furnace to correct it.”

So the Scientist did just this. She created a Thermostat from an Arduino and a DS18B20 temperature sensor.

At first, the new Thermostat caused a few problems. First, the relay would not fire, due to too low a coil voltage. Then, a programming glitch caused the whole house to become quite warm.

The Mystic, visiting his friend, chuckled. “God provides for me, friend Scientist. I have no need of your theories and Scientific Method. See, my house is quite comfortable.”

The Scientist agreed. “Yes, the temperature in your house is perfect. But that’s because it’s early October. You really should consider making a Thermostat, so that when your house becomes cold, it will turn on your Furnace, and make you warm.”

As she spoke, the Scientist continued to refine the thermostat’s design. With a reasonable two-degree-C hysteresis setting and a new drive transistor, the thermostat was soon working well and keeping the house nice and comfortable.

Her job done, the Scientist went next door to the Mystic’s house, to offer advice on how he could also build a thermostat. (The Scientist didn’t always understand the Mystic, but loved his stories and the stained glass and ever-present smell of incense, which made his house a peaceful place.) Making a second Thermostat would now be easy, thanks to the Scientist’s efforts in documenting what did and did not work when building the first one.

“I do not need a thermostat,” the Mystic answered. “God provides for His children. My house is warm and comfortable, since I have built it as my Book of Lore says.”

The Scientist, noting that she could see her breath, was inclined to disagree. “It does seem chilly in here.”

“Ah, yes,” the Mystic replied. “This is clearly a test of my faith. This house is warm. I need no thermometer or furnace. God will provide,” he explained through slightly chattering teeth.

The Scientist shrugged. “Well, if you should change your mind, I will be happy to help.”

And so it was. While the Mystic was able to bundle up and survive the winter (he never did explain the sudden need for blankets in a “warm” house), he was mysteriously ill for much of the winter season. The Scientist, meanwhile, remained comfortable while collecting more data to improve the thermostat’s functionality.

The moral of this tale? Even the wiser religious leaders agree that we must look out for ourselves if we are to thrive — or even survive. Science provides us the power to greatly improve our lives and the lives of others, if we are willing to listen to reason. Science is simply a collection of noting what works and what doesn’t, under various circumstances, and then creating and most importantly, testing hypotheses about how the world works. If a hypothesis doesn’t correctly predict real-world results, it is incorrect — no matter how beautiful it may be and no matter how ancient the text that suggests it.

Mr. Carson: Please start acting like the intelligent MD you supposedly are, rather than an agent of the Spanish Inquisition. You’re embarrassing yourself. Nobody in his or her right mind would question that thermostats work. They work because the science behind them works. Evolution is the same. It really works. It really happened. If your religious views are not compatible with this, then they are wrong.

Posted in Current Events, Digital Citizenship | Leave a comment

Jumping Across The Galaxy

I’ve recently been busy exploring the galaxy in Elite:Dangerous, which I’ve written about before. It’s an interesting game, and the in-game universe is beautiful and awesome, at least once you get away from “civilized” space (where other players and NPCs often shoot at you for no logical reason.)

However, as you quickly find out, the galaxy is a big place. It’s about 100,000 light years (ly) across. Even in a 34th-century starship with faster-than-light drive, that’s a long way. The FTL frame-shift drives in E:D work by jumping from star to star. The farther the destination star from your current location, the more fuel is consumed. Also, for each ship+engine combination, there is a maximum possible jump distance.

When out exploring (heading out to find the lucrative Neutron Star fields, for instance), it doesn’t take long to start thinking of distances in terms of jumps. Soon, those fancy ship accessories start looking more like boat anchors, and you start to think about offloading them to get that last bit of jump range.

But that begs the question — how important is that last little bit of jump range, really? If your ship can do 30.1ly at a jump, is it really worth downgrading to Class D thrusters to get that last little bit of range?

Sometimes, yes, it does matter. If your path goes through sparse patches of stars, gaps in star placement can look like bottomless chasms that cannot be crossed (since none of the stars on the other side are in range.) For want of that last light-year or two, you might have to go around the void, adding many jumps to your trip — or you might not be able to reach these stars at all.

At the other extreme, sometimes more range isn’t important. If you can get to a destination in fifteen jumps with a 30.6ly range, increasing your max range to 31.6ly might not matter, if the best path still has the same number of jumps.

How to calculate this? Well, without the actual data from the Stellar Forge engine, it’s all ultimately guesswork. However, we can take a stab at finding the conditions under which range increases matter, based on a random scattering of simulated stars.

This simulation code (written for FreeBasic for Windows) creates a 1000 x 100 x 100 block of space and populates it with a fixed number of stars. All of the stars except the first and last are placed at random locations within this block, and Dijkstra’s Algorithm is used to navigate from one side of the block to the other. For extremely small jump distances, the ship cannot reach the other side. However, once the available jump range passes a given mark (17.0ly, in one simulation), the destination star becomes reachable. Further increases in jump range often result in the destination being reachable in fewer jumps.

Based on a preliminary simulation of 100,000 stars in the 100 x 100 x 1000 light-year “box,” here are the results for how many jumps were needed to reach the destination. (The same star positions were used for each run, so as to give a fair comparison.) The percentage of stars reachable from the starting position is also given. (Some of these may be isolated along the edges of the box, and would be reachable in a more realistic simulation. Another item for the to-do list.)

Jump Range Jumps TMJ % Efficiency % reachable
15 67 0 35.9
15.5 65 0 40.8
16 63 0 42.69
16.5 61 0 46.87
17 94 59 62.76 52.71
17.5 86 58 67.44 53.84
18 78 56 71.79 60.63
18.5 74 55 74.32 67.35
19 71 53 74.64 68.51
19.5 67 52 77.61 71.05
20 66 50 75.75 72.36
20.5 63 49 77.77 76.79
21 61 48 78.68 77.53
21.5 58 47 81.03 79.69
22 57 46 80.7 84.37
22.5 55 45 81.81 84.72
23 53 44 83.01 84.89
23.5 52 43 82.69 86.41
24 51 42 82.35 86.7
24.5 48 41 85.41 86.8
25 47 40 85.1 86.9
25.5 46 40 86.95 90.51
26 45 39 86.66 90.85
26.5 44 38 86.36 91.34
27 43 38 88.37 91.44
27.5 42 37 88.09 91.6
28 42 36 85.71 91.64
28.5 41 36 87.8 92.36
29 40 35 87.5 92.43
29.5 39 34 87.17 92.44
30 38 34 89.47 92.53
30.5 37 33 89.18 94.02
31 37 33 89.18 94.09
31.5 36 32 88.88 94.14
32 35 32 91.42 94.34
32.5 35 31 88.57 94.63
33 34 31 91.17 94.69
33.5 34 30 88.23 94.72
34 33 30 90.9 96.26
34.5 33 29 87.87 96.28
35 32 29 90.62 96.53
35.5 32 29 90.62 96.57
36 31 28 90.32 96.9
36.5 31 28 90.32 96.96

I’m currently investigating the effects of star density on these calculations. I expect the results to scale according to the average distance between stars, which should intuitively go by the cube root of the number of stars (since a lattice of stars with half the distance would have 8x as many stars per unit volume, on average.)

Posted in BASIC, Coding, Current Events, Math, Science | Leave a comment