Member #134773

Member Since: May 19, 2010

Country: United States


I started playing with electronics in the mid-1960s, and with computers shortly after Neil Armstrong took “one small step”. I got a degree in CS in 1980, and started working then as an engineer.

  • Too bad this didn’t come out about 3 weeks ago. I’ve just done a project requiring a pair of sensors to determine a joint position by the difference in angle of the gravity vector. I used 3DOFs (Adafruit’s 2019) because at the time 9DOFs were way more expensive. The downside of using 3DOFs is that if the joint in question is too close to being in the horizontal plane, the angle can’t be measured. The 9DOF would have provided a fall-back by using the magnetic vectors, though they are FAR more susceptible to “local interference” than the gravity vectors. (Hey, if you have a gravity anomaly that affects which way is down over a 3 inch span, you’ve got much bigger worries than joint position!)

    Oh, BTW, I also used a MicroView to provide both the “compute” and the “user display” for this project. (I’d played with the MicroView when I first got it as part of my original Kickstarter reward, but hadn’t done much with it since then.)

    At the moment, I’m calling this a “proof of concept”. It likely won’t go much further, but I’ll take it as “show and tell” when I go see my doctor on Monday, and who knows what he’ll think. (I hope I don’t have to use this thing too many more weeks.)

  • Nice presentation.

    One comment, though: I not sure whether the IR non-contact thermometer is one of the lower-cost ones that measure at a single frequency. These can be reasonably accurate, and is fine for many uses, but for a more accurate reading, you need to use one of the more accurate (and more expensive) IR thermometer that looks at the ratio between two different IR frequencies to calculate the temperature.

    On a related subject, I once used an IR non-contact thermometer to try to measure the temperature of photovoltaic panels. From the front, I got ridiculous numbers, but from the back of the panels, I got much more reasonable numbers. I finally realized that the PV panels were converting some of the IR energy to electrical energy, thus were most definitely not a “black-body” when viewed from the front.

  • Sure wish you guys would mention the weight on these boxes. There are projects where weight is an important consideration.

  • Infinitely many monkeys sitting at infinitely many typewriters will eventually produce the works of Shakespeare.

    However, they’ll also produce a LOT of garbage. And actual monkeys at actual typewriters will produce a lot of jammed typewriters (from someone who learned to type on an actual typewriter).

  • One “clarification” about the history: The “stencil pen” never caught on (much) as a way to make stencils. However, the technology of stencils to transfer designs is alive and well (I suggest you go down and look at SparkFun’s production line – stencils are used to put a “design” in solder paste onto printed circuit boards, for instance, to make that Pro Micro that you used). Artists also use then to transfer graphics, and have done so since at least the 1100s (when they were used to decorate castles).

    FWIW, if tattoo parlors had to rely on the likes of me, you’d be the leading supplier of tattoo machines as actually having built one this millennium.

    I just remembered that about 10 years ago, I dated (a time or two) a lady who did “permanent makeup” – using tattoo machines and makeup colors to “hide” scars, birthmarks, and such. (That relationship never went anywhere because she was decidedly a “morning” person and I am decidedly a “night owl”.)

  • Do you know Arrow? They’re gigantic.

    Yeah, I know Arrow. Based on my experience at a former employer, if they don’t think they’ll get at least $100,000 a year in business out of you, they’ll barely give you the time of day. (They’ll quite literally give you Digi-Key’s website and gladly suggest you go there instead of bothering them.) I most sincerely hope that Glenn leaves that attitude behind.

    Speaking of Digi-Key, there’s an interesting video of Adafruit founder Limor Fried interviewing Digi-Key CEO Dave Doherty.

  • I’d tried to do something like this for a club’s “national convention” a couple of years ago. Unfortunately, I’d managed to mess up a connection to the EL panel, and couldn’t get a replacement in time, so dropped the project. I had used a “sign cutting” machine to cut out the stencil – I’d pushed it to the limit (on the small end) with the club’s logo.

    Have thought that CriCut machines were an interesting idea – but the manufacturer’s “our designs only” attitude blows it for me. It would be interesting to do masks for SMD soldering as well, if they weren’t such money grubbers. Oh well, they won’t be getting any of my money, at least not until they change their song.

  • Don’t know if you’ve noticed that at Adafruit they have various “inspirational” quotes at the bottom. Paraphrasing one of them (and sorry, I don’t recall who said it), “the most reliable, inexpensive parts in a design are the ones that aren’t there”. (Next time I see that one, I’ll have to copy it down!)

  • FWIW, ALL semiconductor diodes are “light emitting”. It’s just that “ordinary” diodes emit photons, at 0.3eV to about 0.7eV, that are firmly in the “far IR” (or “thermal InfraRed”) range, plus they are usually put into opaque packages.

    When testing chips while they are still in wafers, they have to be shielded from light as virtually all of the devices on the device will act as “photosensors”.

    Also, I think I’d heard about the use before the ED article. I recall a suggestion in the earliest reference I found (when I researched it several years ago) an “app note” from, IIRC, a diode manufacturer, suggesting that in a remote control the LED used to illuminate the buttons could also be used to measure the ambient light to determine how bright the LED should be.

  • One of the things that I’ve been curious about (though not curious enough to look into) is whether these PCB houses can work from standard Gerber files. If so, I’d certainly encourage using KiCad or gCAD instead of the proprietary software. (I’ve always had enough time to be able to use the less expensive places.)

No public wish lists :(