2011.04.02

Modern Sandbenders

11.00.35 - Mark

"I like your computer," she said. "It looks like it was made by Indians or something."

Chia looked down at her sandbenders. Turned off the red switch. "Coral," she said. "These are turquoise. The ones that look like ivory are the inside of a kind of nut. Renewable."

"The rest is silver?"

"Aluminum," Chia said. "They melt old cans they dig up on the beach cast it in sand molds. These panels are micarta. That's linen with this resin in it."


Years ago I read that bit of text in William Gibson's Idoru, and it's been an idea kicking around in my head ever since. I love the idea of casting a 3d circuit holding itself together in the air. The joy of functional art, from recleamed materials and repurposed parts.

It's not the sole reason I bought an Arduino to build a 3x3x3 LED cube, but the whole idea was rekindled by seeing an Arduino Skeleton [via HackADay]. While it's not the aluminum cast circuit Gibson talked about, a steel wire framed arduino is pretty close. I also like how there are some hints on how to make your own substrate less circuit. So tempting...

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2010.05.25

Intervalometer Version 1.3

16.44.40 - Mark

I've been working on my home made intervalometer on and off for well over a month now. I bought the parts for it in early April, bounced between building the original version based on it's schematic and reading up and learning how to actually use 555 ICs in mid April. Finally got the first working version packed into an Altoids sized tin in a frantic morning on April 20th (written inside the tin since I was pulling it off between going to a class then driving 6 hours to go camping for a weekend) About a week after finishing it I got around to putting together a semi-decent time lapse video.

Homemade Timelapse TriggerPart of the reason I had held off on the time lapse is because I wanted this to work as a wired remote for my camera, rather than having to carry around a couple candy tins with switches and cables attached. This however has been my big problem.

The original schematic calls for a NPN transistor to work as the switch for the shutter release. When it's base is getting power, the emitter and collector are bridged and the circuit for the shutter is closed. Since the manual switches are wired in parallel, they can't override a closed circuit and are blocked until the base looses power - be it the few moments the 555 drops power or when the battery is disconnected. If I had gone this way I probably wouldn't have had a problem using it as a wired remote, but it is mentioned as a glitch in the original write up.

In my build however I used a PNP transistor, originally for no reason other than I had a bunch more of them than NPNs and they worked in the breadboard prototype. It's emitter and collector are still the connections for the shutter release loop, but those points are only bridged when the base is grounded. Unfortunately this was a somewhat massive problem for me. It not only blocked me from using it as a wired remote when powered off, the second it was plugged into the camera was the second it would take the first exposure. I could jerry rig it into working in my favor, but I wanted full control all the time.

At that point I started thinking about how to get that control. I first thought of using multiple transistors, looking into Darlington transistors or Sziklai pair, even started thinking of Logic Gates and building them with transistors. All it needed to do would be isolate the transistor from the circuit when the power was off. As I got frustrated with the complex schemes of using transistors to control transistors, I started to rethink the simplest approach of isolating the key PNP transistor.

A quick test on the breadboarded version, and just unplugging the PNP's base made it work with the parallel switches when the power was off. While I could have wired in and mounted another switch, I preferred simplicity, and a DPST switch was purchased to replace the SPST power switch. One side still for power, the other between the 555 and the PNP base. It's a good fix, and I finally feel good documenting my version.

In addition to my use of a DPST switch and a PNP, there are a few other changes I made. The first is the different selection of resistors. While the potentiometer and paired 100k ohm resistors remain the same as the original, I changed the LED resistors to 10 ohm (I wanted some more light coming off the LEDs).

Since I wanted a time lapse mode faster than once every 30 seconds or so, the fastest given by the 220uF capacitor (up to about 4 and a half minutes as its slowest), so I used a SPDT switch and 22uF capacitor to add in a second mode that can shoot as fast as one exposure every 9 seconds (which goes up to ~30 seconds).

I also changed the .1uF with 33k Ohm resistor to a 10uF capacitor and 470k resistor. The original design didn't allow my Canon XSi enough time to run the shutter. This my change is a particularly long break for the shutter trigger, about a full second. While I originally only changed the resistor for a sufficient delay, I realized that the SPDT switch with the key capacitors, really had three positions.
Intravolimeter Schematic
This switch happens to have ON - OFF - ON positions. While I only cared about being able to switch the 2 key capacitors, when testing it I accidentally had it on the off position. When I powered it on it started running the shutter faster than once a second. While I may not be getting this right, when the one of the 2 larger capacitors are connected the circuit is monostable, a quick burst for the transistor, then starts over. When neither large capacitor is connected however, it starts running as a bistable, or flip-flow, circuit, opening the shutter loop for a second, then closing it for a second, with it's pace set by the small capacitor and resistor. While I have yet to find a real reason for this feature, I decided to take advantage of it and added the 10uF capacitor. So, if you follow this design, this gives the camera shutter a full second or so to run when it's in Monostable mode, and get an exposure every 2 seconds or so when in Bistable mode.

While I'm sure there are other changes that could be made, I think I'm done with this one (with the possible exception of designing a real circuit board for it). Between arduinos boards and the parts for building a Camera Axe, I think this will suit me well for a carry around wired remote and intervalometer.

If you want to build one for yourself, feel free to work off my schematic (image above, enlarged, or EAGLE Schematic) put it's still a good idea to refer to the article I worked from in Make Volume 15 or the extremely useful discusion thread on it's Instructables page.

The components are all from Mouser, but I got the perf board from Radio Shack. You can get all the parts there as well (in theory) but they charge a lot for the things they do stock, and sadly my local Radio Shack's component area is a sad disorganized mess. Of course Digikey is on par with Mouser (just a bit harder to navigate) and in this case everything you need (including perfboards) can be purchased at All Electronics (which just takes a good bit of hunting) It's worth nothing however that you can scrounge together a lot of these parts from old electronics.

555 Timer IC Based Intervalometer Part List
Parts
Needed
Part DescriptionPrice Per Part
11M Ohm Potentiometer$.80
1DPST Toggle Switch$1.24
1SPDT Slide Switch$.75
2Tactile Switches$.31
2Tactile Square Caps$.15
2LEDs$.08
1220uf Capacitor$.14
122uf Capacitor$.10
110uf Capacitor$.06
1555 IC$.31
1PNP Transistor$.11
210ohm Resistor$.10
2100k ohm Resistors$.10
1470k Ohm Resistor$.10
12.5mm Stereo Plug$1.55
19v Battery Snap$.38
1Multipurpose PC Board$1.99
Hookup wire
Solder (you should have it)
Enclosure (I used an altoids sized tin)
Total:  $9.01 + taxes and shipping

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2010.04.27

Bluecheese Burgers and 555 ICs

16.55.08 - Mark

Ah, the combination of technology and food.

Well sortof. After dusting off my Canon S3is for it's timelapse feature for Inkinga few weeks ago, and then in the same post complaining about not getting anything faster than 1 shot a minute out of it, I decided to try and make the 555 IC based camera trigger.
Homemade Timelapse Trigger
The version I build was covered in MAKE Magazine Issue 15, as well as a bit more detailed on it's Instructables page. When I described it as "crude" in the Inking rant, I was surprisingly accurate.

While I tried to follow the schematics exactly the first two attempts (the first soldering, the second by breadboarding) I still wasn't getting a working device. Perhaps by my mistakes, but perhaps by design flaws. However after going over it's comments on instructables, I managed to hack together a working solution as well as a couple upgrades to the original design. While it's a bit tempting to document my changes, I'll hold off until I either debug it or create another version.

However, after assembling the components, and shoehorning it into an altoids-esqe case, I wanted to use it. While I've come close to using it a few times over the last week or so, I finally used it last night when I made some Bluecheese Burgers.

The photo rate was about 1 exposure every 9 seconds, Canon XSi camera on tripod, lens set on manual focus but camera shooting in Program mode. I turned off the trigger a couple times (like when the burgers were on the grill) but the whole series works pretty well. And since it's food, written ingredients and instructions are included (both here and in the video)

Bluecheese Burgers

2 lbs Hamburger (85/15 lean or better)
1/8 teaspoon Ground Cayenne Red Pepper
1/4 teaspoon Ground Cumin
1/4 teaspoon Garlic Powder
1/4 teaspoon Salt
1/4 teaspoon freshly milled Black Pepper
2-3 oz. Crumbled Bluecheese
Hot Grill
(All measurements approximate - Cook to your taste, not mine)

Mix all spices and hamburger together.
Divide hamburger and form 8 thin paddies.
Put crumbled blue cheese onto 4 paddies, leaving open space on the edges.
Place remaining paddies onto the blue cheese piles and "seal" the edges of the two paddies together.
Cook burgers on the grill to taste. Roughly 7-8 minutes per side for Medium

Bluecheese Burgers are great on their own, but I prefer them with some Red Onion, slice of Tomato, some Lettus, and a bit of Mayo, but enjoy it however you want to.


Bluecheese Burger Timelapse (2MB 320 x 480 H.264 Quicktime)

Creative Commons LicenseThis work is licensed under a Creative Commons Attribution-Noncommercial 3.0 License.

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2007.10.01

Blink on, Blink off

01.08.29 - Mark

3x3x3 LED cube powered by an Arduino board This afternoon / evening, after a great weekend of camping, I finished up the Arduino powered 3x3x3 LED Cube I started on last week. I ended up making a run out to the local Radio Shack to get some transistors since I was too lazy to try and re-purpose some from the junk pile, then ended up walking out of the store with a breadboard and a jumper wire kit. Spent more than I would have liked to but I think it will end up being a sanity preserver.

The way I ended up wiring it is each column of LEDs gets a connection to an output pin of the Arduino board, and each level shares a cathode connection. Each level has a transistor being used as a switch that controls if the circuit is closed.

Now I'm into the programming part of the project. I'm setting up simple animations and I'm slowly exploring the control structures. Arduino is C based, so I'm recognizing a lot of similar syntaxes to PHP, but I'm getting used to the forced camelCasing (which is something I hate)

As I get more ambitious with the programming I think I'm going to try and add some random functions to it and see about connecting a microphone to one of the analog inputs and make it more of a light organ. I want to get a few more animation sequences developed first.

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2007.09.28

Enough electronics to be dangerous...

02.10.43 - Mark

I've been playing with my Arduino board this evening, and while I have gotten it to work with my Mac, I'm only slightly past the basic LED blinking stage. I need to crack down and read up on the Arduino language and syntax before I try and get into more advanced projects. Not having a lot of spare cash on hand after buying the replacement S3, I'm using materials on hand for my projects, which right now means lots of LEDs. A while back I bought a couple hundred blue LEDs off eBay and they've been sitting around collecting dust, but I pulled them out tonight and I've soldered together 5 LEDs for experimenting with persistence of vision and I'm in the process of finishing a 3x3x3 LED cube similar to this MAKE Weekend Project from a few weeks ago. Somehow I don't think programming it is going to be as easy as building the LED cube...

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2007.09.13

Arduino

00.53.58 - Mark

Cold opens suck, but I finally got around to buying a microcontoller, opting for an Arduino Diecimila. I've been wanting to play with microcontrollers for a while now, but I've never gotten to the point where I bought hardware to play with. I've been reading about Arduino boards though MAKE for a while now, and they seem really powerful. Given the cost ($37 shipped from adafruit) I figured it was time to bite the bullet and buy one.

Other than general experimenting, I'm probably going to try and connect it to the analog gauge I bought a couple weeks ago. I don't know what I'm going to measure, but I'll figure that out one it's in my hands and can experiment.

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2007.08.17

Trying not to kill electrons

00.25.22 - Mark

So in addition to reacclaimating myself to the real world, I've been dealing with broken electronic devices.

Two weeks ago I somehow managed to kill my camera. While it chose a good day to die on me (last day of camp) it's well established that I'm a lot happier when I have a working digital camera. On the plus side Canon's customer service is amazing. I called last Friday and after not arguing with the [knowledgeable] phone monkey, I had the camera packed up and shipped within 90 minutes of looking up the Canon Support Phone number. I've never had that sort of thing happen when calling tech support. Assuming they don't take forever to fix my camera, I've got another reason to love Canon.

The other dead electronics I've dealt with this week is my 91 Honda Accord's stereo, which has been dead for so long most people who get in it have become accustomed to not even trying to coax it into speaking. Rather than trying to fix the factory head unit I opted to install a new Sony stereo that has an iPod dock connector. I probably had about half a dozen people tell me to get it professionally installed, but in reality all it required was splicing together a dozen wires (I used crimp connectors, but if I was doing it over would solder and heat shrink it) then put it in place of the old stereo. Cosmetically it could look better, but I'd rather have a few cosmetic blemishes than fork over $75 (or more) and have it look a little nicer. Besides, installing it boosted my confidence on working on cars. While I've got no problem ripping into delicate electronics like laptops and iPods, cracking into my car was a little more daunting. Might be the fact that I don't place my life at risk when I use my computer...

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2007.03.17

Unsafe at any Amperage?

22.54.58 - Mark

There's a neat round table discussion over at MAKE showing the thought process behind a decision to drop a high voltage project from the 9th issue. The project in question recommended using parts from an old CRT monitor to build a small levitation device.

I've seen these before, they're pretty neat and I can see building one. Even if I don't build it I want to see that article. However I also understand the issues at hand, I've been active on hardware hacking forums for years, and I've seen several dozen sides to the dangers of CRTs argument.

I will personally do some work in AIO macs and have taken apart a couple of monitors, but mucking about in a CRT monitor isn't my idea of a real good time. To date, I've never been shocked and I only have a few basic rules I go by (good insulated gloves, treat CRTs with respect, always have someone nearby in case the worst happens)

Getting to the point, I don't know if they were right or wrong in the decision to kill the article. I'm almost inclined to say they were wrong in cutting it. There are still mentions of the lifter project (page 54 - Electrogravitics), and there were at least two projects in the fringe issue that dealt with high voltage devices (page 66 - Kirlian Photography and page 138 - TV Set Salvage).

What I would probably do, especially where there doesn't seem to be any really solid resource on the threat posed by CRTs, is publish more safety information. Every single science textbook I've ever laid hands on had one of its first chapters dedicated to safety. A safety column or mini-poster in each issue wouldn't add too much cost, but add a good deal of value. Outline the dangers in that quarter's issue and run down the safety measures.

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2006.05.09

Making iPod Accessories

15.23.47 - Mark

iPod Stand I saw this iPod stand on the web somewhere last week (the link with it was to a German forum), and since then I've been playing with the idea of doing sometime similar. I might try and do a charge/sync dock since it's possible to buy iPod conectors in small quantities. The brain storming begins...

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2006.02.24

Pissing off the electron gods again

13.15.27 - Mark

My iPod is without functional hard drive after 3 months, my Cell phone (Motorola v551) is a piece of shit with some of the worsst design and contruction ever put into production, my brothers Laptop, which was "fixed" last week wasn't, and was taken back to the shop Monday, which means its going into its 5th week of repairs, not to mention the extremely wonky car stereo I've got that may or may not produce sound while you are occupying the vehicle.

All that, I can handle.

But today is the last straw. The electron gods do not need to be screwing up my iBook.

We're nottlking softwae screw ups, or even a flaky drive. No the electron gods have felt the need to smite me by making the system not boot up at all. Too far!

I'm about to go into surgery with it to pull the hard drive and make a backup, then see about taking it in for repairs.

Don't woory about me I'm FINE (Freaked out, Insecure, Neurotic, and Emotional)

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2006.02.04

Space Suit Satellites

00.55.30 - Mark

A few weeks ago I heard about a project called suitsat which was repurposing an old Russian Space suit for use as a satellite. They stuck in a Ham radio and a few extra batteries and shoved it out the airlock door sometime Friday afternoon.

It's a neat project with a lot of potential for allowing us to repurpose some of the junk we've launched into space at a cost of millions of dollars. Plus there was a secret message, and secret messages are always fun.

I had been hoping to listen but unfortunately after a couple orbits, both before it made any decent passes near NC, suitsat failed, which is a shame. NASA thinks the batteries froze, so I'm sure they'll cook up a solution and make another disposable satellite. I really wanted to try and listen in some time this weekend and make an attempt at decoding the picture. Of course I though I was magically going to listen on a radio set that didn't support the transmission, but failed hardware on their part means I don't have to admit my brain fart, wait a minute....

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