jeff-o's blog

Hey everyone (who still visits this site),

Voting started today on the SINGER Kids Crafts Contest.  I have one entry in the contest, the Thingamaplush Robot.  I'm fairly sure it will do well, but I'm always nervous about these things.  I'd love to get your vote if you're a member of Instructables!  Of course, you may vote as many times as you like, so if you see other entries that you like please vote for them, too.

Thanks!

Today at work I fixed a board by blowing on it.

I'd been trying to figure out what the heck was wrong with it.  I could see no reason why it was failing, but despite all my hours of work I just couldn't pin it down.  I'd swapped parts and tested continuity between at least 100 points.  For some reason I decided that I ought to hit it with some compressed air, and once I did that, it started working!!  Some thing conductive must have shorted some pins.

So there you have it.  When you're working with electronics, inspect and clean up debris as you work.  Keep your work area clean.  And, remember Occam's Razor.

I didn't get the grand prize, but I did win a sweet Thingamakit from Bleep Labs for my Laser Synth-Guitar.

See all the winners here:  http://www.instructables.com/id/Art-of-Sound-Contest-Winners/

And yes, I will certainly bring in my thingamakit to show off once it arrives and is built.  :)

Hi everyone,

This is sort of a two-part post.  I'd like to describe a simple little project that has been simmering on my back burner for a while, but that I'd like to resurrect.  I'd also like to suggest offering it as a kit that we could sell (hopefully, one of many!) to help fund the Hackerspace.

The project is a simple clock, that displays the time in a matrix of 4 by 9 LEDs.  They are arranged as four colums of 9 LEDs each.  Each column corresponds to a time digit - hour10s, hour1s, minute10s, minute1s.  A separate LED blinks to show seconds.  The whole thing runs on a single ATTiny2313.  Perhaps you saw me show it off at the very first Arduino meeting.

Anyway, I think this would make a great kit to sell, and to offer as a soldering excercise.  I estimate the cost wold be under $20 in parts.  Everything is through-hole and easy to build with only basic soldering expertise.

Why not start today?  Well, the software needs work.  My prototype tells the time just fine, but it needs a bit more flash!  Right now the LEDs just turn on and off during time transitions.  I think it would be great if they "fell" from the top when incrementing, and drained through the bottom when transitioning from 9 to 0.  That'll take some programming skill that I don't yet have.  Is anyone willing to pick up where I left off?  I'm perfectly willing to handle all the hardware stuff, from supplying materials to ordering PCBs from China (and of course assembly).  Let me know and we can meet up sometime to work on it.

- Jeff

P.S. Oh, one more thing.  Once it's done we could write up an Instructable to help promote it!  I'd suggest registering "KWArtzLab" as a usename for this purpose.

Hey everyone,

Check out this project on DIYAudio.com:  http://www.diyaudio.com/forums/showthread.php?s=&threadid=59357&perpage=...

It's a bleeding-edge DAC and headphone amplifier.  It's designed to plug into a TOSLINK (optical) or digital coax connection, and sounds so good you'll hear compression artifacts in anything but well-mastered CDs and DVD-Audio.  How do I know?  Well, someone at my work built one and contributed to later revisions, and says that it's The Best Evar (my words, not his!)

So anyway, I was thinking of building one or two myself (one as a gift).  The trouble is that single boards are expensive, but if you buy a few then the total price goes down.  Same goes for parts, though not quite as dramatically.

Does anyone want to build one, too?  You'll need some elite surface mount soldering skills, though I can help with that if you don't want to ruin the board or parts.  Total cost would be about $250.

Hi everyone!  I've got great news!  My son, Zander, was born yesterday at 4:26pm.  Big sister Kieran is very excited!  He weighed in at 9 pounds 5 ounces.  Mom and baby are still at the hospital resting and waiting for test results.

He and his sister are far and away the best things I've ever made.  ;)

We've already got some soldering classes starting up, why not try to earn a $100 gift certificate from the Maker Shed?

Teach your Family to Solder Contest

I guess that means we'll have to bring some kids and spouses along, too!

- Jeff

OK everyone, this time I'm placing an order at Small Bear Electronics.  If you see anything you like there, let me know and I'll add it to my order.

At last the Art of Sound contest at Instructables has entered the voting phase.  You probably already know that my Prism Laser Guitar is entered in the contest (as are two other projects).  Naturally, I really really want to win, and I'm not ashamed to ask for your votes.  If you're a member at Instructables, take a few moments and vote for me.  You can vote more than once, so by all means vote for anything else that you think is deserving, too!  :)

The Contest

My entries: Prism Guitar, ValveLitzer Redux, ValveLitzer Trifecta

Thanks!

 Attention all programmers!  I'm in the midst of planning my next laser guitar.  Some of you have played the first one, and it's great and all, but it can be so much better!

Here are my goals for the next one:

1. Should sound more like a real guitar
2. The ability to play chords (and, well, melodies)
3. Insensitivity to bright light
4. Battery powered

To that end, here are some of the solutions I'll likely use:

1. Karplus-Strong String Synthesis - a relatively simple way to synthesize the sound of a plucked string, without relying on wavetable lookups!  One filter per string of course, and between four and six strings.
2. Individual membrane potentiometers rather than a single IR range finder will (probably) allow for control over each "string's" pitch and tuning.
3. Red lasers instead of green, with IR phototransistors instead of visible light.
4. I'll try to make this thing run on no more than 9V...

I have two ways in which I may implement that Karplus-Strong algorithm.  I can do it entirely using analog circuitry, using basic RC filters and old skool analog delay lines.  I won't need programming help if I go that route.  Or, it can be done entirely digitally, on a programmable DSP or (maybe) a microcontroller with enough processing power.  That's where I'd need some significant programming help, since I suck at programming...

 Hey Everyone,

I'll be placing an order at Sparkfun very soon.  If anyone wants to add something to the order let me know ASAP!

After over a month of late nights I have finally completed my laser guitar and its associated Instructable.  Take a few minutes and check out the link!  Pass it on to friends, family, and popular blog sites! :D

 http://www.instructables.com/id/The-Prism-A-Laser-Synth-Guitar/

I'll try to add some more videos as I find willing participants to play on camera...

It's rare, but it happens!  Today I took the day off work, and will be spending nearly all day outside working on my daughter's play structure.  Should be fun (and hot!)

Bleary eyed I head to bed, satisfied in the knowledge that my project is drawing to a close.  Pictures in the morning.  Sleepy now.

Apparently, aluminum will turn a dark grey-brown colour if you leave it in orange degreaser overnight.  Oops - not what I had indended, not by a long shot!  It's supposed to be a shiny silver!

Now I'm going to have to sand it down (best case) or completely redo it (worst case).

Remember everyone:  don't put aluminum in citrus degreaser.  Learn from my mistake.

Late last night, around 11pm, my project was finally together.  I plugged it in and... No Lasers!

Yep, after all that work my lasers didn't turn on.  I am using modified laser pointers, hacked to run off a 5V supply...  at least I thought so.  I was wrong in assuming I could use a simple current-limiting resistor to bring the 5v supply down to the 3V the laser pointer needed.  Apparently, these laser pointers are "smart" and won't turn on when the voltage is too high!  So, I've got another order in to Digikey for a 3V LDO (low dropout) voltage regulator, so that I can give the lasers their own fixed voltage supply.  Argh!

Ah well, I also tacked on a few other items, including some knobs (the ones I bought originally were too small) and a case for the power supply.  Everything will arrive on the 8th, a day before the meeting.  Boy, I'm sure cutting things close!

As I finish up my super-awesome audio-related project, today I had the opportunity (and need, I suppose!) to visit a place called Metal Supermarket.  What a fantastic store!  It's basically a small warehouse stocked with dozens of different pieces of metal.  Aluminum, brass, steel, copper, whatever you need.  It comes in sheets and tubes and chunks.  They will cut to size, no matter how small.  Best of all, it's inexpensive - I got an 18x18" sheet of 1.6mm aluminum sheet for $7.  Sweet!

Definitely add this place to the shortlist of stores we're fortunate to have in K-W.  I'd also like to give a shout out to SpaeNaur, my #1 source for just about any fastener you could ever need, in whatever quantity you need.

I'm a subscriber to Ponoko's newsletter, even though I've never actually had them make something for me.  Apparently they will be launching a network of digital "creating" machines in Q4 of this year, in which owners of such machines (laser cutters, CNC machines, etc) can sign up as a branch of Ponoko.  The idea is that when Ponoko gets an order for something to be fabricated, the object could be subcontracted to a fabricator as close to the customer as possible.

LINK HERE

This looks like a good opportunity to earn some cash to help support the Hackerspace.  I assume that a laser cutter and/or CNC machine are pretty high on the list of equipment to buy, so we'd be pretty well set up to act as a branch of Ponoko should we choose.  Money earned could be put towards new equipment, towards rent, or whatever else.  Whoever does the actual work of operating the machine and shipping/delivering the parts could get a rebate on their monthly membership dues.

Well, I'm not sure if my project will be done by the 2nd of July.  The reason?  Paint!  It takes forever to harden to the point that it can be handled safely.  Argh.  It'll be done by the 9th, though...

The wood for the play structure was delivered promptly at 8 am this morning.  I must say again how impressed I am with Home Hardware - if you need building supplies, go there!  It's SO much better than Home Depot.  They have this thing called "service" and on top of that the wood was cheaper!  Go figure.  So yeah - I'll head out and grab the rest of the hardware I need this morning, as well as some tools and stuff (a blade for ripping PT boards, a wood auger bit, bolts, screws, etc).  Then I can get started today!

As for my guitar refinishing, the sanding step went as easily as expected.  My Mouse sander handily removed the last layer of paint, leaving a nice smooth wood layer underneath.  Once I make some mods to the body it'll be ready to paint!