In preparation for the Maker Faire in October, we’re going to be setting up a presentation at our local library. You know those glass case things where people put themes in (old photos, etc). One of those. Ours is going to be filled with some of our electronics projects, the goal being to get more people interested in visiting the Maker Faire.

Since the Maker Faire is more than just electronics, there are a lot of crafts–and some really cool ones, Evelyn figured it was a good idea to include some “crafty” things in there. So, we went looking for some more unusual materials, based on some postings we’ve seen on the Make Blog.

Here are two projects. Can you guess what they were made of? Click the link below the photo for the answer.

Purse

Here is a little purse that Evelyn knitted (or is it crochet?) out of a certain material. Now, some may have already seen her giant bag made out of grocery bags, but this one is smaller and doesn’t use bags. Can you guess what it was made of?

 Click Here For Answer

Purse Morphed Into Hat (Unlined)

This next one was going to start as a purse, but kinda evolved into a hat for a small child. This is the outer design, which I think is crochet work. The idea is to line it with a contrasting cloth. It’s really hard to photograph. Maybe I’ll take another picture when she’s done. Can you guess what it is made of? 

 Click Here For Answer

More great news for coffee drinkers:

Now, one of the largest and longest studies of coffee drinking suggests that coffee may indeed boost your lifespan – providing you drink enough of the stuff, that is. It found that people who consumed several cups of coffee every day were less likely to die of heart disease than those who shied away from the stuff. Heart disease is an umbrella term for conditions including heart attacks, stroke, and arrhythmia.

The researchers found that women who drank four to five cups per day were 34% less likely to die of heart disease, while men who had more than five cups a day were 44% less likely to die.

So, between the Diovan HCT, the Toprol XL, the Zocor, the Tricor, the baby aspirin, and the pot of coffee I drink a day, I should have no fears of having heat disease. This just means I’ll probably get something else. LOL.

A couple of years ago David Rosengarten had an issue of his newsletter dedicated to Japanese food. It was, and still is, an excellent guide to Japanese ingredients. It was a nice breeze through the more popular dishes.

At the time, we lived in Arlington Heights, IL, which has a large and very complete Japanese (focused) supermarket. If you are in the Northwest Suburbs of Chicago, I highly recommend checking them out. The place is called Mitsuwa Marketplace and is fantastic. If you can’t find your “weird” Japanese ingredient there, then it’s unlikely to be found in the U.S. (They are the biggest store in the area, but that whole section, into Schaumburg, has a lot of great mom & pop “asian” stores.)

One word of caution, though. You really need to know what you’re looking for, or can read Kanji, or have a Japanese friend, or are friendly enough to ask the (almost exclusively) Japanese clientele for help. Most everything is imported, and so finding stuff can be difficult. However, most of the goods do have U.S. “nutrition facts” in English, which helps. (I haven’t been there in over 3 years, so things might have changed.)

One of the things I got out of the Rosengarten Report was a product called Furikake. It’s a seasoning mixture that you sprinkle on top of your rice. It comes in all sorts of flavors, though most all are bonito (dried fish) flavored as a base.

If you are just starting our into Furikake adventures, I’d recommend getting a couple of different small packets, like the ones below. You usually get about four little packets inside a bigger package.

I can’t read Kanji, but I like the “blue” (not shown) and “red” ones the best. It could say “Now With More Pig Snouts!” for all I know.

In Austin, we’re lucky to have two Japanese mom & pop stores near us, Asahi Imports and Say Hi. They sell some Furikake in jars, and it’s easier to see what you are getting:

On the left you have “Katsuo Fumi Furikake” which (I believe) translates to Bonito (shaved dried fish) and Sesame Seed. In the center is “Wasabi” which is green, but not hot at all. Actually more sweet than anything else. Almost a “dessert” flavor! To the right is the “Salmon” flavor, my least favorite, mainly because it’s uncomplicated. I like the ones with lots of different bits better. Katsuo Fumi is my favorite of these (though I’ve not yet tried all their flavors).

So, what the heck do these taste like? Well, it’s kinda hard to explain. First of all, these are not some sort of gourmet fresh-from-the-ocean experience. They are a cruncy, sweet, salty, kinda fishy, treat. Rosengarten summed it up well when he called Furikake a Doritos-like experience. It’s junk-food, with artifical colors and tons of savory flavors.

Some warnings for those with allergies: Because these are junk-food-like, they have MSG. Now MSG is a natural flavoring, found in many things, but some people are nervous about eating it. I’d say two things: First, use in moderation. Second, MSG is found in a LOT of food but is NOT labeled as such. When you see “natural flavors” that’s often a code-phrase for some variant of MSG. You are probably already eating a lot of it, but just don’t know it. Finally, and I’m not a scientist but I’ll pretend to be one, I think that a lot of peoples’ “MSG headaches” are actually SODIUM (salt) headaches. Too much sodium can do weird things to your blood pressure. And elevated blood pressure can lead to bad headaches (trust me, I’m on 6 medications to prove it. lol).

Also, if you are allergic to seafood, stay away. Then again, if you are allergic to seafood you probably can’t eat 99% of Japanese food. Finally, most of these toppings use a lot of sesame seed, so if you have a problem with that, stay away. Amazingly, sesame seed is one of those few foods I’m not allergic to. Or, maybe I built up a tolerance?

To “use” Furikake you need some rice. So cook up some Japanese short grain rice in your rice cooker. You MUST use Japanese-style sushi-type rice. It’s short grain and sticky. It’s sticky on purpose, and it’s why you can eat Japanese rice with chopsticks, and why sushi sticks together. An easily available brand, Nishiki, is grown in California and is pretty good.

Once the rice is cooked, you just spoon some into an individual bowl. (Remember, you want sticky rice! You don’t want nicely separated grains. Let the rice cooker do the work for you.) Then pour some Dashi over it (about 2 tablespoons).

What’s Dashi? It’s a kind of soup base. You can buy it in bottle, or make your own. It’s super easy (and cheaper) to make your own. You just need some water, good soy, maybe a little Mirin (sweet rice wine), and some Hon Dashi. Simmer on the stove for a bit and you’re set. You can use it for soup, or pour a little over rice. First timers, who just want to sprinkle Dashi over rice, get the bottle, as it will be less of a hassle.

(Hon Dashi is a sort of soup base, like bouillon. It looks like little pink granules. You use about a teaspoon for every two cups of water. You can get it in little jars. I get a giant 1 kg box that will last me years. You use it to make your soup base, adding some soy, Mirin, garlic, ginger, etc.)

Once you have doused your rice with a little Dashi, sprinkle on some Furikake. Start our with a little, and see if you like the flavor. It takes a little getting used to, especially for those with a western palate. I’ve tried a number of different brands and flavors before I came down to a handful that I really like. The nice thing is you can sprinkle a little at a time, so one bowl of rice can be eaten with a couple of different Furikake flavors. A four course meal in a bowl of rice.

I like making rice with Dashi and Furikake in the summer, as the rice cooker doesn’t heat up the house, and the meal doesn’t feel heavy. You can use it as a simple lunch dish, or as a side with a full Japanese meal.

I saw this on the BBC site the other day. Finally, I thought, some new technology I could really use.

Scientists have shown off the blueprint for an “acoustic cloak”, which could make objects impervious to sound waves. The technology, outlined in the New Journal of Physics, could be used to build sound-proof homes, advanced concert halls or stealth warships.

I am a big hater of unwanted sound and it’s absolutely my #1 pet peeve. It’s also a problem that really needs to get solved, especially as energy prices skyrocket, forcing people to live more closely together than ever before.

Evelyn has recently been working on a bat detector, which translates the ultrasonics of the bat echolocation to frequencies that the human ear can pick up. Basically, it takes the input frequency and divides it by 4. So, a bat sonar might be going off at 60,000 Hertz (cycles per second) and the frequency divider brings it down to 15,000 Hertz (well within the human hearing range). The unit also has two amplifiers (located before the divider) which boots the signal picked up by the ultrasonic transducer (sort of a microphone for high frequencies).

We knew that the unit worked in the lab (you could hear “pest eliminators”, rattling keys, etc), but we wanted to see how the unit worked with real bats. Lucky for us, we live in a town with lots of bats.

Last night Evelyn and I went down to the Congress Avenue bridge in Austin to check out the bats. The bridge, right on the Texas Colorado River, downtown Austin, is a home for a huge (millions) colony of bats. They all start emerging from under the bridge at around sunset.

We brought along our field test unit, which was specially designed for us to easily adjust amplifier gain in the field. This allows us to pick ideal values using the transducers we own (we plan on making a kit out of this project, so we need to carefully test things out).

Here’s a photo of Evelyn near the lower part of the bridge:

She is testing out the unit. It uses headphones so that it doesn’t “feedback” into itself.

Here’s a shot looking up from the river edge. It’s a constant stream of bats:

How did the unit work? Surprisingly well. You can hear the bats streaming overhead. In fact, you can use the device to tell when the bats are moving in your direction. This is because high frequencies are very directional, unlike low freqencies. That’s why it’s hard to determine where the “boom-boom” of an overly-loud car stereo is coming from, but you can pinpoint a high pitched sound. Also, lower frequencies can travel further, and can pass through materials, while high frequencies are attenuated very easily. It’s also why bats, and other animals, use ultrasonics: They are very accurate–the same reason why robot builders use ultrasonics for their range finding equipment.

For a great deal of time the device was almost swamped, given the millions of bats going overhead. It sounded a lot like TV static. And yet, when you remove the headphones, they are silent.

You see ribbons of bats, like in the photo below:

It was probably the most intersting when you heard only a single bat or two, as you can clearly hear them click-clicking their way through the night. Again, they are completely silent to the human ears, unless you have a device to bring their ultrasonic frequencies down to the human range of hearing.

In fact, even when there aren’t bats, the world is full of ultrasonic noises. You hear them when you jingle keys, snap your fingers, and so on. Our next experiment is to find good (loud) sources of ultrasonics in the world around us. Things like “pest eliminators” (they are VERY loud in the ultrasonic range), automatic doors at stores, motion detectors (some of them), and so on.

(Full sized photos are in our Photo Gallery, for those wanting a closer look. Here is a direct link: Congress Avenue Bat Bridge)

Here’s a photo of the Peggy 2.0 LED board in action. I’ve put in 11 test LEDs (just held by friction, not soldered). It seems to be working fine. Those are big 10mm LEDs. It’s driven by 3 “D” cell batteries.

It took less than 2 hours to complete. Most of the soldering was pretty easy. The time consuming part will be soldering the 625 LEDs, which is why I want to think through my color choices carefully before starting that adventure.

While my example LEDs are on the front-side, I’ll probably mount the real ones on the back. That way the electronics and batteries won’t show on my LED End Table project. Plus, it will make getting at the batteries, programming headers, etc, a lot easier.

We recently picked up some cool 8×8 LED Matrix parts from All Electronics. These are neat because they have 8×8 LEDs in one package. We were going to start working with them, until I realized we had no data sheets (and they don’t have driver chips, which some people use).

A search of the internet came up with squat, and the Lite-On site wasn’t much help either. They had data sheets, but not for this part. So, out came the multimeter, the power supply, and some prodding and poking. Hopefully this information will help out others trying to use this part.

It’s from All Electronics, catalog # DMD-7. The Lite-On part number is # LTP2B88AG-NB. It’s an 8×8 green LED matrix. It has 16 pins for control (8 for rows, 8 for columns).

Here are my UNOFFICIAL data sheets for this part. I can’t tell you for sure if I have the columns and rows mixed up, or which side is up, but I’ve made my diagrams consistent so it will get you going.

This is how I labeled the Rows and Columns. The printed label / part number is toward the bottom. The numbers 1 through 16 indicate the pins underneath.

Here is the polarity for the pins, as tested with my handy power supply and a drop resistor. I manually checked each pin, so these should be accurate.

In the above photo, the unit has been flipped end-over-end. Again, the number scheme of the pins is what I came up with, based on best guesses from partial Lite-On sheets. I think I have it right, but who knows. At least I’m consistent.

Finally, here is how you light up each LED by column and row. The first number is the Anode (Positive) pin. The second number is the Cathode (Negative) pin.

If anyone finds the real data sheet, or can confirm my results, please let me know in a comment. If you need jumbo-sized photos, I’ve loaded them in the Photo Gallery.

For anyone who’s trying to use some of the projects as a jumping-off point, you may find higher resolution photos helpful in figuring out your own designs. I’ve also organized the Electronics stuff by project, so you can check out things you’re interested in. Just click here or on the “Austin & Puerto Rico Photos” link to the right.

Well, I just finished up installing the boards inside the radio. I mounted the MP3 to the top board with zip ties and the controller board with some bolts and standoffs. Here’s a photo of the completed interior:

On the rear board (bottom of photo) you have the AC power connections, fuse holder, AC power switch, and AC LED Indicator.

Inside the radio, at the bottom, you have the transformer (right), and the two power supplies (5V and 3.3V) on the left. In the mid section, you have the power terminal strip (black thing, attached to left wall), the audio amp (small board in upper left), the MP3 player (center, toward back of radio), and the MP3 control board (longer board below speaker). The ribbon cable connects the control board with the MP3 player. Audio goes out through a standard 1/8″ headphone jack and plug.

Here it is, all closed up:

And now, on to the next project!

Another day, another project idea. I’ve been looking at the Peggy kits from Evil Mad Scientist for a while, starting with their Peggy 1.0. It is basically a giant LED lite-brite. Very cool, in that you could drive a ton of LEDs. However, I didn’t like the fact that you had little or no control over individual LEDs. Regardless, it gave me the idea to make some sort of LED endtable.

So, we’ve been looking for suitable end tables. The Peggy board is big (about 12″ x 14″), so the table needed to be big. Also, because of the LEDs, battery pack, etc, the table needed to have enough depth to hide that stuff. Finally, and most importantly, the table needed to have a glass top. A pretty big top, so that Peggy would show through. Problem is that most of the glass topped variety are 70′s retro, with the cheesy chrome frames (which do me no good, because they won’t hide the electronics).

We looked at the usual spots (World Market, Target, Hobby Lobby) but couldn’t find much. Anything that came even close was well over $100. Well, last week, while coming home from our walk, we saw that people were moving out. And guess what was sitting at the dumpster? A black wooden end table. Big enough to fit a Peggy. Deep enough to hide the Peggy. And, amazingly enough, has a smoked glass top of EXACTLY the right size! Fate could not have presented us with a more perfect table. (And thanks to Evelyn for telling me I’d be stupid [in so many words] not to grab it. She was right.)

Here’s the garbage-picked table. The legs have been removed (they just screw off) for this photo. It stands about 24″ off the ground with the legs. It’s actually quite an attractive table. The wood is in good shape, and the glass has only the tiniest of scratches.

Here’s a side view. It’s about 4.5″ tall, so we have plenty of space to put the electronics. It’s quite a husky table, so I’ve got not worries about it being a stable platform for this project. Horray! I wish I knew where it came from, so I could direct others to it. It’s made in China and has a label of “AL3000″ but that’s it.

So, now we have the perfect table. Time to order the Peggy. As luck would have it, Evil Mad Science recently came out with their enhanced Peggy 2.0 board. This is a huge improvement, for two major reasons.

First, it allows you to individually control each LED on the board. Keep in mind, this is a “lite-brite” of 25 columns by 25 rows. That’s 625 LEDs on the board! Quite a few “pixels” to be sure. To be able to control each of them independently is a huge step forward, and pushed me to purchase it.

Second, and just as important, they are now using the popular hobbyist Atmel ATMEGA168 microcontroller. This is the same controller as found on the Arduino board. Plus, the Peggy 2.0 can be programmed via the Arduino development environment. This is fantastic, as it’s easier for me to code in pseudo-C than Assembly. There’s even programmer connections right on the Peggy, so I can plug my programming cable in without removing the chip from the circuit. Heck, I could even monitor the Peggy from my main computer (used to write the code) over the programming cable.

These two modifications made Peggy 2.0 a must-have if you want to drive a lot of LEDs in a sign-like fashion. They have made other changes too, which are just as nice, like making the sides borderless, so you can lay Peggys next to each other in continuous lines.

Yesterday we received our Peggy 2.0 kit in the mail from the folks at Evil Mad Science. Here’s what the bare board looks like. It’s the largest printed circuit board (PCB) I’ve ever used:

Along with the board, I ordered about 500 10mm LEDs of different colors. I got a variety because I wanted to see which colors look best, and I’m not sure exactly what I’ll do with the Peggy (besides put it in an end table). The 10mm LEDs are great, because they are jumbo-size. On the Peggy, they sit very close to each other, so you have an almost complete covering of LED light. Very cool.

An aside: If you are looking for inexpensive 10mm LEDs, I’d recommend checking Evil Mad Science out. I checked prices at other places, and EMS had about the best deal. They must be buying them in very large quantities. A 100 LED bag is between $20 and $30, depending on color. That’s 0.20 to 0.30 cents for a 10mm LED. Not bad at all. Plus, they have some good deals (100 for $20) on the smaller 5mm superbright blue and white LEDs. They are pretty bright, the blue especially. Good deals.

I like their translucent 10mm green and blue the best. The red and yellow are pretty typical. The white is diffused and good, but don’t expect extreme brightness. Their pink 10mm is the most interesting color, and we used that for Evelyn’s bat sign. If we were to do another bat sign, I think we’d try the blue 10mm. I can’t wait to see 625 10mm LEDs lit at once.

The downside, is that, unlike the lite-brite, the LEDs are soldered in place. (Some sort of socket arrangement would be too unstable, and expensive, I would think.) So, this means I really need to think about how I’m going to use the board.

Will I use all one color and have it run Conway’s “game of life“? That’s actually been done already, and it’s cool. I’ve also see people do all one color to make 25×25 LED “photos”. Pretty neat, also.

My thought was to make it into some sort of lo-res gaming table. Perhaps a maze game? Pacman? Tetris? Or something else? I was thinking card games, since the positions of the cards is fixed. I have the arcade joysticks, and there are pads on the board for connecting buttons, so it’s possible.

Or, do I do something more abstract? Like fractals? Do I arrange Reg-Green-Blue LEDs in sets and create a pseudo RGB color board? I wonder how that would look (something to breadboard first).

Like I said, there are a lot of possibilities, because I can individually control LEDs in code. However, I still have the limitation that a “pixel” can only be one color, so the layout of the 625 LEDs has to be carefully thought out.

What are your ideas?