Anton wrote in to ask:
I want to purchase your Larson Scanner kit but need to be able to run it from household current … is there a converter that you would recommend?
Since the Larson Scanner normally runs from 3 V DC, a regulated 3 V power supply can be hooked up in place of the 2xAA battery box. However, 5 V power supplies (like this one) are much more common, and the circuit can be run from 5 V with only minor changes. if you replace the nine 16 ohm resistors in the Larson Scanner kit with 120 – 150 ohm resistors, you can power it from 5 V directly.
Another related question we occasionally get is how to run the Larson Scanner with green LEDs. (Note: by green, we mean “pure” green LEDs which have a forward voltage of about 3 V. Older style yellow-green LEDs with a forward voltage of ~2 V can be used as drop-in replacements for the red ones.)
If running off of battery will work for you, this is an even simpler change: merely replace the 3 V battery holder with a 4.5 V one, such as a 3xAA. It is a happy coincidence that the circuit can run with red LEDs at 3 V or green LEDs at 4.5 V using the same 16 ohm resistor value. So how about running a green Larson Scanner from a 5 V power supply? Replace the nine 16 ohm resistors with 39 ohm resistors and you should be good to go.
You can find the documentation for the Larson Scanner and more stories about modding it on our wiki. We’d love to hear about any mods you do to the Larson Scanner in the comments or see pictures in the flickr pool.
There are some gems on the list of HTTP error codes, including some that you may not have encountered before. We particularly like this pairing with the “Utah” teapot.
Photo credit: Windell H. Oskay/evilmadscientist.com
I had a wonderful conversation with Elecia White of embedded.fm which you can hear in her 40th episode, titled Mwahaha Session.
I brought along a Snap-O-Lantern kit for her to give away one of her listeners, and you can find details of the give-away on the podcast page.
Ben wrote in with a great question:
I had a quick question regarding the Three Fives Kit. First of all I just wanted to say that great job on the kit! I LOVE mine and it was a blast to put together. I just had a quick question about one of the packing items used when the kit is shipped. I loved the resistor organizer/holder you shipped the resistors and have been trying to figure out where to get them. The best I could guess was that they are sewing needle holders, but I have been unable to find them as such.
Many of our soldering kits have multiple resistor values, but the Three Fives kit is unusual among our projects in having nine individual resistors of different values. This presented an interesting problem: how to make user friendly packaging to make it easy to find the right resistor. Sure, you can read the color code stripes, but that can be a pain for folks with color blindness or just plain old poor vision.
Our solution was to design a custom wallet, modeled after needle packets, to hold and label the resistors with their locations & values. The resistors are dropped into slots, secured with a label, the cover flap is closed over them and then tucked under a tab. During use, each resistor is simply pulled out from under the adhesive label.
The wallets are laser cut out of sheets of 60 lb manila cardstock. It bends easily along the perforations, but is very sturdy and can withstand many repeated bends. (Aside: this weight is very similar to punch cards, which—to go full circle—is what I use for storing sewing needles.)
We reused the wallet with a different label when we released our multi-colored Menorah and breadboard Menorah kits, which also happen to use nine resistors in a variety of values.
Today we’re releasing this resistor wallet design in two versions: one for nine resistors, and one with slightly narrower spacing to hold ten.
If you use our resistor wallet, we’d love to hear about it or see pictures in our flickr pool!
Gregg posted on twitter:
WaterColorBot experiments: moss+yogurt and algae+iron paint. With William Jennings.
We’ll be looking forward to seeing followups on these experiments!
Over at Dead, too much lettuce., Scott built an Access Point garage door opener with a Raspberry Pi, an Arduino, and our Simple Relay Shield.
I bike to work. Bikes live in the garage. But with only 2 remotes, I could not keep one in my bag all the time to be able to get to the bike. So a new option had to be created. Most people would have bought a new remote…
Not long ago, I participated in a workshop at the Institute for the Future on what they are calling Extreme Learning. They have just launched a site to provide resources for alternative learning paths and to share stories of extreme learners (like mine in the video above). On the extreme learners site, there are more stories from the workshop participants, who were a fascinating group from diverse backgrounds. This project is a part of the Future of Learning program.
We’ve rounded up our Valentine projects for your last minute preparations:
If one of our projects inspires you make something, we would love to hear about it in the comments or see photos in the flickr pool!
In the 1870s, Eadweard Muybridge, using brand new photographic techniques, helped settle a bet about whether horses lifted all their feet off the ground at once. His iconic pictures of horses in motion are frequently used in arts and crafts. (Aside: we even ran into them at Maker Faire in a FlipBooKit animation.)
Amanda found a file on thingiverse of outlines of the Muybridge horses that were intended for use for laser cutting (for animation purposes). She remixed it for use with the Eggbot to make the horses go around the egg and published her Muybridge Carousel design on thingiverse.
Photo by Amanda Geyer
Last year we released a set of six equation-heavy ”Download and Print” cards for Valentine’s day. This year, we’re doubling the size of the collection (to twelve!) by adding six more cards, this time heavy in symbols, not equations:
“You turn me on” …with an SPST switch.
“I can hardly resist you.”
There is room for a future superconductivity joke here, involving a phrase like “I can’t resist you (below a certain temperature).”
You can download the full set — including the 2013 cards — here, a 500 kB pdf document.
As with last year’s set, print them out on (or otherwise affix to) card stock, and [some steps omitted] enjoy the resulting lifelong romance.