UptownMaker

In mathematics, a degenerate form is one that cannot be perturbed in some way without being rendered a member of a larger, more complex class.  For example, a circle is a degenerate ellipse- change the constant multiplier of one of the terms and you push the form out of the class of circles into the larger class of ellipses. Next time you're solving a problem, ask yourself: am I solving for a degenerate form?  And, if the answer is yes, is that important?  Let me give an example where the answer to both questions was "yes".  I was tasked once with supporting some motion code which was intended to align a circuit board on a conveyor belt under a camera. The code as written worked fine in the lab, but in the field, customers began to complain of erratic and unpredictable behavior- boards which would be incorrectly positioned at the start of inspection, pushed off the end of the conveyor, etc.  It turns out that the code had originally been written to the dege...

Whenever you put a project out there in the community, be it on your blog, a community board, or as an article in another venue (or if it gets picked up by say, Hackaday or Make), you're bound to get some comments that are, shall we say, worth less than the calories they took to type.  Worse still are the times you get these comments from someone to whom you are explaining (in meatspace) your current pet project- those times can be a SERIOUS buzz kill and I've lost the will to finish a couple of projects after comments like this. "You know, Target sells something that [does that]/[does almost exactly that]."  This is more common in meatspace than on the web, I think, because the web audience self-selects for people who understand that the joy is in the making, not the having.  And, frequently, the "almost" is where the bugaboo lies- I want EXACTLY that, not ALMOST exactly that. "Arduino is for losers."  Or some variation thereon.  Arduino, as a p...

... as proposed by Jeri Ellsworth:  the "Jones", after EEVblog's Dave Jones. As with all SI units, we must define it in terms of base units, so I propose this: 1 Jones = (# of complaints about a topic) * (sum of levels of annoyance caused by said complaints weighted by exposure frequency to causative events, in seconds between exposures) * (# of people likely to be exposed to your ranting) Obviously, the level of annoyance varies from person to person; I imagine a level 1 annoyance ("mild eye rolling followed by repetition of action until desired result is achieved") for a more patient colleague might be a level 5 annoyance to me ("loud sigh with posture change and muttered profanity") and could rank to a level 100 for someone else ("widely distributed internet video rant with attendant behavioral change and increased probability of property damage to exact retribution on an inanimate object"). As a practical example I'll float m...

On the heels of a few tweets regarding linear voltage regulators that I passed with a friend yesterday, I think I'll do a couple of posts on voltage regulation. First, the general concept: voltage regulation is the creation of a stable, low-impedance DC voltage source from an unregulated DC voltage source.  Examples of unregulated DC voltage sources are batteries, "wall wart" type AC/DC converters (even though many of these create very good voltages (these days, anyway), you should always assume that you (or someone else) will plug a different supply in), car cigarette lighter sockets, rectified and filtered transformer outputs, solar panels, fuel cells, dynamos, and fruit with pieces of zinc and copper in.  In fact, pretty much anything other than a locally generated voltage from a well-designed regulator circuit should be treated as an unregulated source (for design purposes, at least). This first post will concentrate on linear voltage regulators.  Sometimes you...

A common problem in electrical engineering is the use of a resistor divider to create a circuit which derives a second (lower) voltage from a known voltage.  This can be for a reference voltage to an ADC (as on the Arduino) , to set the voltage on an adjustable regulator (where the regulator seeks to maintain an output voltage adequate to produce a set voltage at a feedback node), or to calculate the gain on an amplifier circuit, among other possibilities. The canonical voltage divider circuit Usually, we know Vin and Vout, but R1 and R2 are unknowns.  We usually pick one of them (based on what's on hand, in the parts library, time of day, dog's birthday, roll of a 20-sided die, etc), then calculate the other.  Almost always, that results in a value which is not readily available, so we pick the closest value, calculate the error, decide it's too much, and pick another resistor value and start over. Error in the output voltage has a number of possible sources:...

Somehow I've become a prolific blogger lately.  I wonder if this will last... Today at work I had a serendipitous moment of seeing two desktop objects in an abnormal light: a small, scavenged lens cell and a super cheap (2 for $5) LED flashlight. As part of my on-going inculcation into the mystical arts of optical engineering, one of my fellow engineers demonstrated to me the ease with which an illuminated object can be projected onto a surface, if the various distances are correct.  His demonstration was with the image of the lit window that faces our cubes, but it occurred to me today that, by tweaking distances, I could probably get a similar image from my LED flashlight, writ large on a blank whiteboard. Tah-dah!  What's more, I found that, by moving the lens slightly along the optical path, I could bring different elements of the LEDs into focus.  But lets start by analyzing this image. First, you can see (though not very well) that the LED lenses are f...

Once you've got it all together, where do you use it? My workspace is divided in half- an electronics bench with tools and a PC station.  The PC desk is boring- two 19" monitors, speakers, printer, etc- I won't bore you with pics of that. There are only a couple of things I really want to mention here as being special about my desk.  First, the knife holders.  These are the standard type of wall-mount magnetic knife mounts.  Mounted vertically (because they were too long for horizontal) they hold my small tools- little screwdrivers, a wire stripper, a side cutter.  I have duplicates of all of these tools in the mobile kit but it's nice to have them handy. Secondly, the whiteboard.  It's magnetic so I can stick stuff onto it, but it's really more useful as a whiteboard- I'm a big believer that whiteboards are the stuff engineering magic is made of.  I have four of them in my cube at work, and one of the smartest facility design elements I've eve...

In part three, I'll show off my mechatronics tools and parts kit.  Part four will be my workbench and parts storage; that'll probably follow pretty closely on the heels of this since I'm so totally snowbound I really can't do anything else.   It's bigger than it looks.  I had a hard time with this box- it was one of those tool boxes that new homeowners who fancy themselves "handy" buy, which are inexpensive, totally lacking in adequate internal division, and end up full of things like rusty hacksaws, dull chisels, ruined putty knives and inexplicable sheet metal items with flanges and numbered mounting holes. As always, mouse over for labels. Mostly self explanatory; I'm going to mention a couple of things by name.  First, the Pocket Ref on the left side.  My copy predates Make but you can get it from the Maker Shed.  If you don't own this, you should  It has ALMOST everything you'll ever need to know- from the density and chemical com...

If necessity is the mother of invention, snow day boredom is the drunken dorm-mate who will ultimately get you picked up by the campus police. If you're outside of the Minneapolis/St Paul metro area, you may only be cursorily aware of the current snow-tastrophe .  We've gotten about 12 inches so far (300mm for you post-Imperialists) and are expecting another 4-6 (100-150mm).  I managed to get my car safely embedded into a snowbank off of the snow emergency route I live on (read the rules regarding that here - it's harsh but necessary), and, after digging and pushing out a few more people on the walk home, I got bored. My work has been throwing out shoebox sized coroplast boxes for a while now; and being, as I am, on the verge of collapsing into full-on hoarding behavior, I've been picking them up and carting them home.  I've probably rescued about 800- there's a stack taller than I am at the Hack Factory.  Anyway, I use these things for everything- as boxes ...

Of course, the world is replete with articles like this but I recently had cause to write down my thoughts on the issue and I feel like a little more on it couldn't hurt. Why did I get involved in Twin Cities Maker back in 2009, before there was a space?  Simple- I wanted to be part of a MEATSPACE community of people that likes to make stuff.  It didn't exist, so when I found the group, there was no way I could NOT get involved.  I think people who worry too much about virtual space replacing "real" interactions should look at hackerspaces as a dynamite counterexample.  By definition, the people who are involved in these groups are the most likely to be tech savvy, the most likely to participate in online communities of informational interchange about their hobbies, the most likely to be creative basement hermits, AND YET, increasingly, they are seeking out face-to-face interaction as an adjunct to their online work. The tools, the workshop space, the raw mat...

Some thoughts below on NDAs, patents, and people seeking project help from me when I'm wearing my freelance engineer hat.  A lot of this comes from having followed the Piclist mailing list for about 10 years, as well as reading quite a bit of Don Lancaster's writings on the matter- as well as a healthy dose of professional dignity imparted to me by the conflation of engineering with other highly skilled professions such as law or medicine during college. NDAs Sometimes I'll get a feeler e-mail about someone who wants to work with me, and they start off right away by saying "if you're interested, let me know and I'll get an NDA out to you right away." I don't mind working under an NDA (under certain conditions), but some things about being hit up by it right away like that scare me: Once I sign this NDA, if I subsequently complete or publish a project which is remotely similar to this person's idea, there is a legal document which could caus...

Adafruit had a post a few weeks ago about building a cyclorama to take nice pictures of your work.  I built one up for the office (we always have horrible pictures of things in our documentation), but for home I can't justify even the $50-75 one would cost me.  So, I did what any good maker will do- hit the junk piles! First, a word on sourcing:  the local IKEA has a section right before the checkout called "As-is".  (My wife and I frequent IKEA for some reason- we eat breakfast there about once every couple of weeks, and dinner there almost as often.)  As-is is where IKEA goods too good for the trash but too bad to sell as new go- returns, scratch and dent, display models, etc.  Every so often, they'll bundle up a bunch of crap and put it on a "mystery cart" or a "handyman's cart".  The shelves just visible to the right above were a handyman's cart item; the lights all came from a mystery cart.  I've actually bought far too many ...

33:  Booklet printing I don't know why I didn't see this feature on printers earlier but I love that I can print out a document designed to be folded in half and stapled in the middle.

Side trip from my regular posts on organizing your work space and taking it with you:  tools that you didn't know you needed. Most of the tools in the toolkit are obvious- the soldering iron, the tweezers, the "helping hand", etc.  There are a few items that are in my toolbox (or are always close at hand) that I use constantly but somehow never make the lists I've seen for equipping a bench. 1. Cyanoacrylate adhesive- especially the brush-in-bottle "Krazy Glue" brand that I highlighted in my tool kit post.  Useful for "dead-bug" assembly, reattaching lifted pads, and temporarily holding things in place while you work on them (I know many CNC machinists who use CA to hold their workpieces down while they are in process. 2.  Hot glue gun- super useful for low-cost ruggedizing, strain relief, conformal coating and mounting PCBs.  Nothing fancy- a standard low-temperature hobby gun will work fine.  In fact, the high temp type take a little too lo...

I was down- hard- yesterday with a bad bout of food poisoning, which brings me to the 32nd item I love about living in the future: 32.  Symptoms of disease are easily available- Of course, this has it's downsides.  While the SYMPTOMS are often widely available, as are the prognoses, sensitivity and specificity are often ignored, as are any kind of information about likely age groups, races, gender types, risk-enhancing behavior, etc etc. In other words, it's better at ruling things OUT than ruling them IN- but it WAS comforting to know that the very serious food-borne illnesses generally don't have the symptoms I was suffering through.

I've been obsessing over how I can plan a trip to Maker Faire next year using the train...online travel reservations are pretty spectacular, since I can try different departure dates and travel permutations and find a cheap option.  I should write a Python script that spools out dates and returns prices...

Or at least, any PC.  I need to figure out how to do this from my phone...

In part 1, I covered my mobile electronics kit .  This time around, I'll look at my mobile electronics toolkit. While the mobile kit contains (almost) everything I need to do some breadboarding of circuits, more permanent hacks, installations, disassembly of finds and really fun stuff is all bound to require more advanced tooling than the cheesy $5 multimeter (that link shows it for $13, but it's available locally in the Twin Cities at AEI for less than $5, and with a bulk discount option)(yes, I have purchased multimeters in bulk) and adjustable wirestripper in the kit.  After a few scrambling debacles where I realized I didn't have what I needed to finish the job, I decided that I'd best come up with a toolkit that I could use at home and on the road. After some hemming and hawing at the local Home Depot, I bought a Stanley XL Tool Organizer , which is a nice fold-up unit- essentially, two of the more conventional see-through plastic lid boxes that fold up arou...

Of course, it kills my productivity, but it's pretty much what I've always dreamed of- someone says, "here, I think this might be interesting to you" and I have all the reading I can manage.

28.  Projects on the internet Instructables, Makezine, forums, etc.  I remember a time where you had one option for example projects involving microcontrollers: the PIC16F84.  That persisted well into the 21st century- WAY beyond the point where the F84 was a viable product.

Mr. Jalopy's famous side one, track one of the Maker's Bill of Rights is all well and good, but more basically, if you can't FIND it, you don't own it. Owning an object has a cost, however minor, associated with it.  You'll have to move it if you change residences, you have to keep your kid/cat/ferret/sugar glider away from things you don't want smashed/pissed on/drug under your couch/scent marked by a weird oily forehead gland, and clutter (IMO) occupies mental real estate we can usually ill-afford to waste.  If you're going to pay these costs, you should take care to keep your gear well organized so these costs aren't wasted when it comes time to use something. As a hackerspace-going maker, I find myself with an additional constraint- if I want to work on a project at the shop, I need to either bring what I need (tools and materials both) or be darn sure I know what and where stuff at the shop is.  My solution is a robust, scalable, compact group ...

27.  Geek culture Growing up geek was hard (I'm not going to claim it was as hard as growing up gay would be, naturally)- especially because my formative years were spent in a small school (less than 90 students from preschool through 7th grade) where a sizable number of the attendees were there as a school of last resort. So it does me some good to see the embrace of geek-dom people like Wil Wheaton bring to the world, and to see that being a geek is no longer anathema.  I'm sure it's still hard on teenagers and kids in small schools, but maybe it's getting better.

Recently I was approached by an architecture/design firm to help with an electronic install at a client site. The client had requested a system that interacts with users in the bathroom- "interacts" meaning, hassles them when they come and go. I spent some time debating how to do this; hacking an MP3 player would be easy, but keeping the devices synchronized is a pain- how do you play one sound, at random, then stop until the next input? The Adafruit Waveshield is nice and easy, but the sound quality is poor (22kHz 16-bit mono). Plus, the cost is kind of high for what you get- $30 for the Arduino and another $22 for the Waveshield. Searches for a cost-positive MP3 shield failed me (there are some out there but they are really quite pricey) and the MP3 trigger somehow eluded my search. It was around this time that Adafruit offered for sale the  Chumby Hacker Boards . I decided that I'd do the project with that- it was a bit more expensive but it offered the bene...

24.  Wireless internet 25.  YouTube A million monkeys with a million camcorders will generate more garbage than can possibly be imagined.  Fortunately, there are a million OTHER monkeys pre-sorting it for me. 26.  Injection molding Okay, not new, but the last few years have seen an EXPLOSION of inexpensive goods come from China's vast injection molding farms.  I'm not a big fan of cheap plastic crap, but there is some REAL gold hiding in that sludge.  The inspiration for this was the ease and low cost of putting together some really awesome mobile making kits lately.  Will post more anon, with pictures.

23.  Batteries Lithium based rechargeable batteries rock my world, even if they are much harder to hack.

22.  Digital music Compressed digital music, in particular. 10,000 songs in your pocket.  What's not to like?

21.  Machine vision There are a surprising number of machine vision applications out there these days- 2D barcodes, out-of-lane detection in cars, and manufacturing.  This is a result of the dramatic increase in available computing power- as data transfer rates go up, image sensor integration gets cheaper and more complete, and processing cycles get cheaper, the number of applications will go up as well. Which begs the question- why does the TSA need to people to look at my naked body on the scanner?  Presumably, any thing a person would see could be seen by a computer; if the area of interest were cropped and presented to a human for follow-up, then a more thorough search could be ordered. I suspect it's for the same reason voting machine companies have told us it's "impossible" to issue a paper receipt- failure of imagination coupled with hidebound ways of doing business.  And money, of course.  Lots and lots of money.

20.  Twitter What I don't like about Twitter is the incessant navel gazing (tweets of the "why hasn't he called?" ilk). What I LOVE about Twitter is the ease with which it levels the playing filed for the sharing of ideas and information.  People rich and famous to, well, me, can post something on Twitter, (potentially) gain a following, and disseminate information.  Provided it can be shared in 140 characters or less. The bandwidth restriction is something else to love, in the same way as it is for text messaging.

I suck at daily blogging. 17.  Blogging (did you really not see this coming?) Both creating and consuming.  It's nice to see what's going on out there, what other people are doing, and to share your ideas and achievements yourself. 18.  Tabbed browsing Despite its attendant, the Wikipedia tab plague.  It seems like such an obvious thing I'm amazed it took so long to come to fruition, although it probably only feels recent to me. 19.  Super-easy free open-source software development I am thinking in particular of Arduino, Python, and Processing (which I have yet to play with).  Between the fact that these can be freely downloaded and used by anyone for anything and the massive culture of sharing tricks, tips, and how-to docs, you can pretty much figure out how to make a computer (either a PC or an embedded system) do what you want, quickly and easily.  And cheaply.

16.  Laser cutters Cheap laser cutters (well, cheap is relative) can now cut any shape you can imagine out of some pretty useful materials.  Acrylic, thin plywood (say, 1/4" or so), vinyl, and most other types of plastic can be sliced into intricate shapes for your home projects. Wish I could afford one...

I'm struggling to keep up with this every day- it really is hard to carve 5 minutes out for it. 15.  Ubiquitous cellular connection Weak but it's true.  I have no idea how I managed to see my friends before we could connect via cell phone.  Although, for me, pre-cell phone days were college and high school, so I saw my friends around in person far more often. 16.  E-commerce I can buy pretty much anything, anytime.  For someone with slightly esoteric hobbies (electronics still doesn't have enough clout to get really great local stores), that's a must.

14.  Online banking This one is actually a prime reason why I'm doing this.  I was paying bills, transferring money and generally budgeting our lives when my wife pointed out how amazing it is that I can do that all online. It's become so normal, so natural to me that I completely overlooked how incredible cool it is. 15.  Hackerspaces I think that about covers that.

13.  USB It seems like it's been here forever, but USB is a relative newcomer when stacked up against things like the parallel interface, serial ports, and PS/2, which are still (relatively) ubiquitous.  We forget the bad old days, before hot swappable input devices were the rule, printers had cables that could actually bend with less than a one-foot radius, and adding more devices was a simple matter of plugging in a hub. USB gets some flak from nerds for it's hub and star topology, inefficient use of bandwidth, and relative lack of hackability.  It wasn't that long ago that the people were really worried about what the disappearance of serial ports and parallel ports from PCs meant for hacking; with the advent of product lines like FTDI's USB chips that emulate serial and parallel interfaces, I think all but the most die-hard serial fans will agree that we've come out ahead.

12.  Optical mice I'd never thought of it before just now, but there are TEENAGERS out there who likely think "mouse balls" is a euphemism for some social disease. Every once in a while, I come across a really old non-optical mouse somewhere in my company at some old, old workstation and I'm reminded anew why I love my optical mouse.  Remember when the ball would hit a grain of crud and just...stop, in one axis?  And you'd have to back it up and give it another run?  Picking it up and jiggling it helped, too, sometimes.  And let's not talk about the cleaning process... If you want to have some real sadistic fun, find a friend who is old enough to have spent a lot of time working with a ball mouse but young enough that that time was highly formative (30-35, long term nerd), and put some scotch tape over the optical sensor on his/her mouse.  The result will be a recalcitrant pointer that behaves a lot like a ball-mouse with a fouled roller. Then watch...

11.  LCD monitors I honestly never thought I'd see the day when a 19" LCD was not only affordable, but SO affordable that I would have TWO of them sitting side-by-side on my desk.  When I started college my 17" CRT was larger than standard, and we marveled at the 19" that one of my friends brought back after the summer.

10.  Digital watches I still think they're a pretty neat idea.

9.  Wikipedia Any self-respecting information hound will nod in sympathy when you mention the Wikipedia tab plague (which reminds me- tabbed browsing may be number 10): you head to Wikipedia to look up, say, chi-squared tests for random variable distribution, and two hours later you're reading an article about the history of the Boxer Rebellion or the scuttling of the German fleet in Scapa Flowe at the end of WWI.  You've completely forgotten why you pulled Wikipedia up in the first place, and you may have missed a meeting.

I tweeted on this a couple of weeks (months?) ago, but it's important enough a concept that I think it bears repeating because it applies to a lot of work that engineers (and, really, anyone) does. For the less historically-inclined, the Maginot Line was a series of defensive fortifications between France and Germany built between the World Wars.  France, tired of Germans tromping through their country every couple of decades, elected to try keeping them out by putting fortifications, guns, traps, and big, strongly worded signs in several languages all along the border with Germany. And it worked- the Germans were utterly and completely repelled by the Maginot Line's defenses.  Of course, they went AROUND them and attacked from the north, but by God, they didn't cross the Maginot Line! In the engineering world, there can be a tendency to do the same thing.  If one manufacturer's product has a defective lot, design them out!  A particular technology (e.g, tant...

Three-for-one today, because I pretty much didn't touch a computer all weekend.  I need to figure out how to pre-post things. 6.  High resolution dislpays As Apple has famously pointed out , our eyes are capable of absorbing much greater detail than digital systems typically provide them with.  "Normal" vision (ie., not SEVERELY color-blind, or capable of being corrected to 20/20 with reasonable glasses/contacts) allows for a tremendous data density in a small package, and displays are finally starting to catch up with that. 7.  Gaming as a force for good Some folks out there have finally recognized that the competitive spirit can be harnessed for good- from MMOs like WoW being used as economic microcosms and social fishtanks to competitions in neighborhoods to reduce power consumption. 8.  The local food movement This is a fave of mine, because it means that it's now possible to buy locally grown food direct from the farmer at prices comparable to t...