Hackaday Editors Elliot Williams and Mike Szczys geek out over the latest hacks. This week we saw a couple of clever CNC builds that leverage a great ESP32 port of GRBL. The lemonade-pitcher-based submarine project is everything you thought couldn’t work in an underwater ROV. Amazon’s newest Dot has its warranty voided to show off what 22 pounds gets you these days. And there’s a great tutorial on debugging circuits that grew out of a Fail of the Week. Plus, we get the wind knocked out of us with an ambitious launch schedule for airless automotive tires, and commiserate over the confusing world of USB-C.
Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!
Here’s a Big Mouth Billy Bass with extra lip thanks to Alexa. If you’re not already familiar, Big Mouth Billy Bass is the shockingly popular singing animatronic fish designed to look like a trophy fish mounted to hang on your wall. In its stock condition, Billy uses a motion sensor to break into song whenever someone walks by. It’s limited to a few songs, unless you like to hack things — in which case it’s a bunch of usable parts wrapped in a humorous fish! Hackaday’s own [Bob Baddeley] combined the fish with an Amazon Echo Dot, connecting the two with an ATtiny84, and having Billy speak for Alexa.
[Bob] had a few problems to solve, including making Billy’s mouth move when there was audio playing, detecting when the Echo was on, moving the motors and playing the audio. After a bit of research and a lot of tweaking, a Fast Fourier Transform algorithm designed for the ATtiny was used was used to get the mouth moving. The mouth didn’t move a lot because of the design of the fish, and [Bob] modified it a bit, but there was only so much he could do.
It’s all well and good for the fish to lie there and sing, but [Bob] wanted Billy to move when Alexa was listening, and in order the detect this, the best bet was to watch for the Dot’s light to turn on. He tried a couple of things but decided that the simplest method was probably the best and ended up just taping a photo-resistor over the LED. Now Billy turns to look at you when you ask Alexa a question.
With a few modifications to the Dot’s enclosure, everything now fits inside the original mounting plaque and, after some holes were drilled so the Dot could hear, working. Billy has gone from just a few songs to an enormous entire library of songs to sing!
It takes a surprising amount of planning and work if you want something to look old. [vemeT5ak] wanted the Echo Dot sitting on his desk to fit a different aesthetic motivated by a 1940s Canadian radio. Armed with Solidworks, a Tormach CNC, and some woodworking tools at Sector67 hackerspace, he built a retro-futuristic case for the Amazon Alexa-enabled gadget. Future and past meet thanks to the design and material appearance of the metal grille and base molding wrapping the wood radio case. The finishing touch is of course the ring of blue light which still shines through from the Echo itself.
It took about 15 hours of modeling, scaling, and tweaking in Solidworks with an interesting design specification in mind: single-bit operation. This single-bit is not in the electrical sense, but refers to the CNC milling operation. All pieces are cut with a 1/4″ end mill, without any tool changes. Metal pieces were milled from 6061 aluminum and the hickory case (with burgundy stain) was mostly cut on a table saw, but the holes were CNC machined.
What looks like an otherwise perfect build has a single flaw that eats up [vemeT5ak]’s soul; the Echo Dot has a draft angle that wasn’t considered during modeling, and the hole is ever so slightly too wide, meaning it didn’t press fit perfectly flush. Fortunately it’s not noticeable behind the metal grill, and unless you knew (please help keep his dirty little secret), you would think everything turned out perfectly.
It turns out building a case for the Echo Dot is challenging for a few reasons; the rubbery material on the bottom doesn’t allow anything to stick to it, and the sides are smooth and featureless with a taper that makes it difficult to lock it in. Many cases resort to clipping over the top to hold it in place. Others install it into a fish or a furby.
[Wisecracker] likes how the Amazon Echo Dot works, but he doesn’t like how they sound or how they resemble hockey pucks. A little 3D printing, though, and he transformed the Dot into a credible Death Star. That doesn’t sound very friendly, we guess, so he calls it Alex-Star.
What makes it work is the Death Star’s “superlaser” — the weapon operated by a console that looks suspiciously like some studio video equipment — happens to be about the size and shape of a two-inch speaker. [Wisecracker] added a slot to let the sound out of the second speaker. You can see the thing in action in the video below.