A Rotary Dial Bluetooth Telephone

I have seen a number of rotary phone-to-Bluetooth or rotary phone-to-cellphone conversions on the web, I thought I would try my own.  First step, figuring out how the phone works.  This has been pretty amazing because all of the sequenced and ordered events that happen when you pick up and dial this phone happen mechanically.  Very elegant (and requires 0 amps).  Second, let’s just see if I can hook this old handset up to the old Jabra ear-thing and see if it works: it does (I added a parallel 300 ohm resistor to the mic tone it down a bit).  Next step, figure out the receiver switch and make it a “momentary” action to pick up and hang up calls from the ear-thing.  I think I am close: stay tuned…

This Remote Control Easter Egg has 16,581,375 Colors.

The color can be changed using any button on any TV, DVD, or VCR remote. It is basically a riff on a few of the RGB LED project already seen here, just inside a white egg with an IR sensor. 

I wrote up an Instructable for the whole thing here:

http://www.instructables.com/id/This-Remote-Control-Easter-Egg-has-16581375-colo/

All the parts from Ellen’s Proton radio.

A Small Victory: Modifying the Parallax PIR

Ahead of using the Parallax PIR for a project, I had a problem.  

OK, first: A PIR is a Passive (or Pyroelectric) InfraRed Sensor.  It detects motion by looking at heat (IR) in front of it.  You have probably seen one of these in an outdoor light that turns on when you walk by.  The one I bought is just the detector module (made by Parallax).  Costs $10.  It signals through a connector and lights up with a red glow when it detects motion.

SO, the project.  I am trying to use it to monitor my cat’s movements during the day and here is the problem: the glow that turns on inside the device catches her attention, wrecking the objectivity of this observer.  This cat and I have played one too many hours with the red laser pointer and thus, she love red lights.

I would like to turn the glow off.  

The dome appears to be glued closed and I do not want to crack it getting to the LEDs.  The other option is to modify the PCB and deprive the LED of power.  But how?

I wrote Parallax an e-mail, explained the problem, and without a whiff of legaleze, they just sent me the schmatic for the device.  Just like that.

Awesome.  Above you can see that the LEDs in question (labeled in yellow) and the connection that needs to be broken (orange arrow).  Follow the little pin through the board and the trace that feeds R10 is easily seen on the front of the device.  I scratched through it with an Exact-o knife and broke the connection.

Now the device works the way I want it to: it signals through its connectors without lighting up.

Hat’s off to Parallax for open sourcing it!  Now to build the rest…

(Oh, and modify your own PIRs at your own risk, of course!)

In which I re-package a set of desk speakers

These speakers used to be in a pair of weird beige fusiform pods that loomed ugly, but sounded great.  I have now liberated them from their futuristic plastic coffins and put them into wooden boxes (‘wish I had a “before” picture for you, but I don’t).  I separated out the amplifier and put it into the middle box.  Now they sound great but look a little better.

In Which I Finally Complete the Table.

About a year ago, I threatened a table, and then, by any number of distractions or excuses, sat the table top on a pile of boxes and used it without building the legs. Last Saturday, I impulsively stopped by a lumber yard, scribbled some sums on my hand and left with 8 lengths of 2x4 for $11.03. Thirty minutes, 32 nails, and 8 screws later, the whole thing is together, more or less as planned all that time ago. But alas, now I need a chair.

Programming The ATTiny85 using Arduino 

I recently saw instructions on the MIT High-Low Tech blog for using the Arduino microcontroller board as an ATTiny programmer.  The ATTiny is a programmable chip just like the Arduino, but it has fewer pins, less memory, support for fewer commands.  For projects that are just responding to the environment, keeping time or making things look pretty, not much more than that is needed.

I built a “shield” for the programmer, which is hardly necessary, given the simplicity of the wiring diagram, but it means faster set up, less troubleshooting mistakes.

First project was to program an ATTiny to randomly flash some colors on an RGB LED.  This little LED actually has 3 lights inside: red, green, blue.  The chip powers each color with a random amount of current and one of 16,777,216 colors appear.  The chip waits for half a second and picks again.  In principle, the colors only repeat themselves every 96 days, but I am not really keeping track.  (And yes, a Flashing Las Vegas Ping Pong Ball is kitschy and weird, but its MY kitschy, weird thing.)  Next idea: a visual thermometer: no numbers, just color, as in “oh look! The weather is Fuschia today!”  I’ll let you know how it goes… 

The Light Theremin - Manhattan Style Construction

Make magazine’s Weekend Projects has issued a challenge to construct one of their circuits in any other way than how they planned it.  Here is my go at it.  Manhattan style construction has appeared a few times on the Make blog and is popular with the ham radio crowd.  It involves an un-etched piece of copper clad board with small “pads” of clad board super-glued to it.  These little islands act as the connection points between components and can be added quickly or snapped off if needed.  The larger piece of board serves as the ground so it is always easy to solder into.  

Learning to Make Boston Baked Beans

During a recent trip to visit my parents, I was asked, as the New Englander, how Boston Baked Beans are actually made.  I answered that I had no idea - partly embarrassed (I have lived in/around Boston for years), partly indignant (I was raised in The South). 

AT ANY RATE: as it is tradition here to, well, Explore, I set out so that it might be learnt.

So, first of all, why bake beans?  It turns out that baking beans in this fashion (and the less well known, but still findable, Boston Brown Bread) were convenient ways for observant protestants to assemble a meal in a hot oven on Saturday night and eat said hot, cooked meal on Sunday without doing any “work” on the Sabbath.  Fair enough.  We here at KGETU are probably less virtuous, but just as hungry.

Second, what should they taste like?  According to an old New York Times article I found, the two places in Boston that still make The Beans the old way are Durgin Park (Est. 1827 (or 1742)) http://en.wikipedia.org/wiki/Durgin-Park and The Union Oyster House (Est. 1826) http://www.unionoysterhouse.com/.  This is great because both of these places are an easy walk from the lab.  First observation: not as sweet as beans from a can.  Second: definitely tasting the molasses (as opposed to brown sugar).  

Next: recipes?  On the shelf we actually have a 1909 printing of Fannie Farmer’s _Boston Cooking School Cookbook_.  It is the kind of cookbook that has no temperature or solid timing instructions.

From this book (and other sources) I put together a recipe that works in 2011.  And it works well.  We have prepared these half-a-dozen times at this point and they are good.  If you try this recipe, let me know.  I am curious if it works for others.

1) Soak 2 cups of dry navy beans in water overnight.

2) Next day, drain and rinse the beans.

3) Pre-heat the oven to 325 F.

4) Boil the beans until the skins bust open when you blow on them (about 30 minutes).  This actually works.  And it adds a sense of fun and theater to the dish.

5) While the beans are boiling, brown about 2 ounces of salt pork (fatback) on low heat.

6) To a ceramic cooking dish, add the beans, 2 tablespoons molasses, 4 tablespoons of sugar, ½ teaspoon of salt, the salt pork, and enough boiling water to cover the beans.  Stir.

7) Cover with foil and bake in the oven for 3 hours.

8) About half way through, check on them and add boiling water again if needed.

9) Remove from the oven and allow to sit covered, overnight, on the counter or stovetop.  Do not remove the foil.  (And throw out the piece of salt pork before serving.) 

And yes.  Salt pork is just awful to deal with.  I have tried to make them without it and it just is not right.  And yes, the recipe basically takes 48 hours.  But they as very tasty and very inexpensive.

So there you have it.  I have also made the brown bread, and it is great, but I am still tweaking it.