Our friend Rick stopped by to show us his latest project, which he calls Podtique: a podcast player built into an antique radio cabinet. Using the original knobs, you tune in on “stations” which play different podcasts, with realistically generated static in between.
The whole thing is run on a BeagleBone Black, and uses NeoPixel backlighting behind the dial. He’s written up the build on his blog, posted his code on github, and shared a heap of build photos in an album on flickr.
Leigh Klotz, author of Ham Radio for Arduino and PICAXE, gave us this interesting chip from the 80’s to play with: a UM3482A “Multi Instrument Melody Generator” IC. While not quite rare, it is a bit of a vintage curiosity these days, and we wired one up to see what exactly it does.
The vintage Radio Shack Archer package it came in was minimalist (though not quite this minimalist as it came to us– imagine that the chip were still there in the bubble). It promises not just 12 tunes, but circuit diagrams as well.
This Archer-branded datasheet (including the promised circuit diagrams) came stapled to the back. You can download a readable copy of the manufacturer’s original datasheet here.
“A mask-ROM-programmed multi-instrument melody generator, implemented in CMOS technology. It is designed to play the melody according to the previously programmed information and is capable of generating 12 songs with 3 different effects: piano, organ, and mandolin.”
Amongst the twelve musical selections are London Bridge, Row Row Row Your Boat, Oh My Darling Clementine, and (of course) Happy Birthday. Suggested applications included toys, door bells, music boxes, and telephones. (File under: Customized ringtones of the 80’s?)
The three little graphs in the upper right show the three different timbres (the “instruments,” in the phrase “multi-instrument”) in terms of amplitude versus time. The other diagrams show how to wire it up to a speaker and how to configure the various inputs to select which song to play and so forth.
We breadboarded up a sample circuit from the datasheet, substituting with parts we had on hand, including a little magnetic buzzer as the speaker. A 2xAA battery holder is connected up to the power and ground rails. There is a momentary button switch to select the next melody in the set, and a row of DIP switches to set the configuration options.
And sure enough, it plays melodies.
Chris wrote in:
I wanted to say thank you for writing your blog and the products you’ve created. I used both to make my christmas lights this year. Couldn’t have done it without you.
I used an ATmega xx8 mini dev kit programmed with an ISP shield to control a series of WS2811 LED pixels to make beautiful light. The controller is designed to be standalone, not part of a bigger system. I used a BCD thumbwheel switch to select up to 10 looks.
We can give credit to the FastLED Library team for the heavy lifting. The case is from your friends at Adafruit. The target boards don’t quite fit in the Adafruit cases. Thankfully ya’ll had the schematic PDFs posted and I saw I could literally cut corners to make them fit.
Back to why I appreciate what you do so much, growing up my dad tried to teach me about electronics. He was putting motorola 6802 CPU’s in Sperry New Holland hay bale wagons. Unlike how easy we have it today with Arduino he had to program in assembly…
I got a degree in Theatre and loved doing sound and lighting design. So I really love the art you put into your technology. I’ve built many of your kits. My favorite are the interactive LED panels. Blinking lights! I like to put them behind the ikea glass “white boards” so my ideas really shine when I write them down. I’m looking forward to seeing what you do in 2015!
Darren posted pictures of his UV erasable coffee table which was inspired by our 555 footstool.
The top lifts to reveal the compartment inside and to provide a taller table surface.
There are lots of build photos in the imgur set, and more details in the reddit discussion.
In October, we released our Solderless Flickery Flame project, based on a tiny breadboard with six red and yellow candle-flicker LEDs, to give a fun and semi-realistic flame effect. Today, we’re releasing two new Flickery Flame Soldering Kits along the same lines, each of which has 6 candle-flicker LEDs, a little circuit board, and a battery holder.
The Yellow/Red kit has the same mix of yellow and red candle-flicker LEDs that works so well in the breadboard kit. This one will look great in a jack-o-lantern, luminaria, or scale-model fireplace.
On the other hand, the White/Warm White kit has a mixture of (cool) white and warm white LEDs that give a modern wintery flame effect that has at least as much charm, but won’t be mistaken for a natural fire. This one will look great in all kinds of winter holiday decorations, luminarias, and props.
Both the Yellow/Red and White/Warm White kits are fun, low-cost, self-contained, and easy soldering kits, which will be right at home both as stocking stuffers and as bite-size first projects for soldering workshops.
We were sent a picture of handsome cat Gandalf with an array of green Octolively kits all built up.
Mr. Pumpernickel also looks great in the green glow. Both Gandalf and Mr. Pumpernickel are continuing in a longstanding tradition of cats and interactive LEDs.
Harley Cat (who passed away a few years ago) helped test our very first interactive LED project: our Interactive LED Dining Table.
Jellybean helped demonstrate a later project: our interactive LED coffee table. She is featured at about 48 seconds into this video.
Joyce wrote in this year with her latest Pez Menorah (using our Deluxe LED Menorah kit), featuring a Star Wars theme.
She also wrote up a thorough set of instructions on tumblr, which looks like a remarkably easy way to publish a step-by-step tutorial without using a platform like instructables. It may take some getting used to reading chronologically, but it is effective.
Previous Pez Menorah posts:
After seeing our Larson Scanner kit, Martin shared this LED metronome project with us. Martin says:
It was designed as a “Visual Metronome” So a learning music student could help see the timing by watching the green light. There was to be an optional clicking sound by using a small solenoid for the ticking – I chose that in place of a speaker for a more authentic sound.
The timing is a standard 555 timer which is fed to 7442 BCD to DECIMAL counter. Next chip is a 74193 UP/DOWN counter. When the count hits the last number, it sends a pulse to reverse the count or start over – depending on the toggle switch on the side.
There is also a pot on the 555 to control the speed. All this was made in one night while I was working the graveyard shift.
The entire LED display was hand wired using a manual wire-wrap tool.
The chip pin labels on the back of the perf board are a particularly awesome relic of a different era of electronics assembly. Thanks for sharing your project photos and video with us!
We are very pleased to introduce something that we’ve been working on for most of this year: WaterColorBot version 2.0!
The WaterColorBot is our collaboration with Super Awesome Sylvia: A friendly art robot that moves a paint brush to paint your digital artwork onto paper, using a set of watercolor paints.
Version 2.0 brings it to the next level with some greatly improved hardware. First and foremost, the carriage that holds the brush has been completely redesigned:
The carriage on the original WaterColorBot was made from laser-cut plywood, with nylon bushings and two simple delrin strips that formed the vertical flexure translation stage. (You can read more about the original carriage here and here.)
The new carriage consists mainly of two pieces of metal. The center block of anodized aluminum is CNC milled, and houses crossed linear roller bearings. Wrapped around that is a laser-cut and formed aluminum part that mounts the brush-lift motor, cable guide, and the flexure stage.
The new flexure stage is built with two custom flex circuit boards, used in this case as mechanical flexures. Each board consists of a very thin (0.1 mm, 4 mil) Kapton sheet with a thin fiberglass (G10/FR4) stiffener on its center section. With the two ends of each sheet clamped rigidly and the stiffener in the center, each flex circuit is to flex only along two well-defined lines. And with two boards, it forms a neat parallelogram linkage, without the slop that one might encounter in multi-part hinges. The net effect is that this new flexure stage has remarkable stiffness compared to the old design.
That stiffness, combined with the improved performance of the linear ball bearings makes this a more precise WaterColorBot. Not that you could even detect the improvement with a fat brush and watercolor paints, but things are looking quite good even with using ultra-fine point drawing pens, as you can see above.
The second major change is to the system of Spectra cords that the stepper motors control in order to move the carriage. Previously, the cords were guided around 11 plain bearings (stainless steel solid rivets) and 3 ball bearings. We’ve simplified this into an arrangement of just 8 ball bearings— four for each motor. The ball bearing pulleys have also been updated to use wide V-groove bearings that are easy to wrap the cords around.
Which brings us to the third (and last) major change. Thus far, WaterColorBot kits have shipped “some assembly required” — with all the major components built, but the cord lacing left to the end user. As of 2.0, WaterColorBot kits now come fully assembled and tested. That doesn’t make them any less hackable, but it does mean that you can get up and running faster.
Version 2.0 includes the same CNC machined aluminum winches that we introduced back in August. Tiny detail: we’ve carved a subtle indentation into the wood around the winch that makes them a little easier to turn by hand.
The new WaterColorBot kits will begin to ship right after Thanksgiving. And a bonus present for the holiday season: Version 2.0 is priced the same as the previous version, it’s just a whole lot more awesome per dollar.
The Digi-Comp II we made for MIT is featured in this outreach video from MIT+K12 Videos by Jamie Teherani about how computers work. The mechanical switches on the Digi-Comp II are compared to first to light switches and then to transistors. Regarding manufacturing computers with transistors, Jamie says, “We can make them over a billion times faster than the Digi-Comp!”
