[Fran] Is Helping Santa Slay This Year

December 22, 2019 by Kristina Panos 3 Comments

We know at least one person who ought to make Santa’s ‘nice’ list this year. [Fran] was probably near the top of it already, but sending Santa a handmade greeting card with a fully-functioning guitar amp inside will probably make him rewrite her name in glitter, or silver Sharpie.

This stocking stuffer-sized amp is based around the LM386 and the bare minimum components necessary to make it rock. Everything is dead-bug soldered and sandwiched between two pieces of card stock. The first version with a single 386 sounded okay, but [Fran] wanted it louder, so she added another stage with a second 386. [Fran] glued the rim of the speaker directly to the card so it can act like a cone and give a better sound than the speaker does by itself.

All Santa needs to rock out is his axe and a small interface made of a 1/4″ jack and a 9 V wired to a 3-pin header that plugs into the card. He can take a break from Christmas music and let some of those cookies digest while he jams. Be sure to check out the build video after the break if you want to stay off the ‘naughty’ list.

Want to make your own musical greeting card? If you can program an ATtiny85, you won’t need much more than that to send a smile. If visual art is more your thing, 3D print them a 2D picture.

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Santa Claws: Sharpen Your Skills For A Good Cause

December 18, 2019 by Kristina Panos 2 Comments

Want to do a bit of good this holiday season without leaving your couch or battle station? Well step right up and try your hand at Santa Claws, the charitable claw machine created by UK-based firm Liberty Games. For every toy you can maneuver to the chute, Liberty Games will donate money to Crisis, a national charity devoted to ending homelessness.

The machine is filled with special Christmas-themed stuffed animals that represent different cash values from £1 to £5. And these toys are doing double duty — after the holiday, they’ll all be donated to a good cause. In order to make this playable worldwide, Liberty used a Raspberry Pi, two Pi Face boards to interface the claw machine’s controls, and a Pi Face rack to everything together. They have the machine set on ‘generous’, so go have fun.

Has this rekindled a longing for your own claw machine? Yeah, us too. Here’s a full-size machine that runs on a Teensy.

Old Christmas Tree Gets A New Spin

December 15, 2019 by Kristina Panos 9 Comments

A couple of Christmases ago, [Nick] got tired of trying to evenly decorate his giant fake tree and built an MDF lazy Susan to make it easy as eggnog. But what’s the point of balanced decorations if one side of the tree will always face the wall? This year, [Nick] is giving himself the gift of a new project and motorizing the lazy Susan so the tree slowly rotates.

The saintly [Nick] decided to do this completely out of the junk box, except for all the WS2811 RGB LEDs on order that he hopes to synchronize with the tree’s movement. He started by designing a gear in OpenSCAD to fit the OD of the bearing, a task made much simpler thanks to the open-source gear libraries spinning around out there.

It was hard to get slow, smooth movement from the NEMA-23 he had on hand, but instead of giving up and buying a different motor, he designed a gear system to make it work. Our favorite part has to be the DIY slip ring [Nick] made from a phono connector to get around the problem of powering a rotating thing. This is a work in progress, so there are no videos just yet. You can watch [Nick]’s Twitter for updates.

[Nick] didn’t specify why he chose to use WS2811s, but they have gotten pretty cheap. Did you know you can drive them with VGA?

Via Adafruit’s CircuitPython newsletter

Don’t Hang Christmas Lights, Embed Them

December 10, 2019 by Kristina Panos 1 Comment

Finding it hard to get into the holiday spirit this year? Maybe you just need a timely project to light up the evenings until Santa (or Krampus) pays your house a visit. Whoever visits this season, delight or distract them with a 3D printed tree featuring embedded RGB LEDs.

[MakeTVee] printed this tree in four stages to make it a little bit easier to wire everything up. Each stage has six LEDs embedded in a 5mm transparent layer at the bottom. The top stage has a second color change to make a tree topper that holds a single LED. The color change feature in PrusaSlicer 2.0 made it easy to pause the print, insert the wired-up LEDs, and resume seamlessly in green filament. There’s a hidden base of what appears to be appropriately delicious cinnamon filament that holds the Trinket M0 and the power switch.

This lil’ tree looks great, especially considering how fiddly and nerve-wracking the wiring and assembly must have been. [MakeTVee] made it easier on himself with a printed wiring stencil that holds the LEDs in their star formation while he solders them up with magnet wire (a solid choice in our book). He thoughtfully included that stencil in the files which are up on the Prusa site. Dim the lights, grab a hot beverage, and check out [MakeTVee]’s build video after the break.

If you want a holiday hack that people can play with, invite them to paint your addressable tree.

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Cooking A Turkey With 880 AA Batteries

December 2, 2019 by Lewin Day 52 Comments

Cooking a turkey right is serious business this time of year. With major holidays on the line, there’s no room for error – any mistake can leave guests disgruntled and starving. [Stephen Farnsworth] took a risk, though, and attempted to cook a turkey using AA batteries.

The allure of the AA for such a task is precisely because it’s such a poor choice. Designed for portability rather than high power output, it was never designed to be the energy source for a major cooking job. To get things over the line, [Steve] busted out the math to figure out how many batteries would be required. This involved computing cooking efficiencies, battery thermal performance, and the specific heat of the bird itself. With the numbers coming together a 300W slow cooker was put on duty, in order to avoid over-draining the batteries.

With 880 AAs loaded into a custom carrier, [Steve] hooked up the power meter and the cooker and kept a close eye on the temperatures. After a couple of hours, the battery pack started to heat up, so additional cooling was brought in to avoid fire. At just before the six hour mark, the turkey was cooked through and ready to eat. Estimates are that the batteries still had plenty of capacity to keep going for a few hours yet, too.

It’s not a fast or effective way to cook a turkey, but it’s certainly achievable. We fully expect [Steve] to submit the coin-cell turkey cook-off next year, too. Remember, a little engineering always helps, especially in the kitchen. Video after the break.

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Check Your Halloween Candy For Malicious Payloads

October 28, 2019 by Lewin Day 31 Comments

There’s long been much handwringing around Halloween around the prospect of pins, needles and razor blades being hidden in candy and passed out to children. On the very rare occasion this does happen, the outcome is normally little more than some superficial cuts. However, for 2019, [MG] has developed an altogether different surreptitious payload to be delivered to trick or treaters.

Consisting of a small USB device named DemonSeed, it’s a HID attack gadget in the genre of the BadUSB devices we’ve seen previously. When plugged in, the unit emulates a USB keyboard and can be programmed to enter whatever keystrokes are necessary to take over the machine or exfiltrate data. Files are available on Github for those looking to replicate the device.

The trick here is in the delivery. [MG] has produced a large quantity of these small devices, packaging them in anti-static wrappers. The wrappers contain a note instructing children to insert them into their parent’s work computers to access “game codes”, and to share them with their friends while hiding them from adults.

The idea of children brazenly plugging hostile USB devices into important computers is enough to make any IT manager’s head spin, though we suspect [MG] doesn’t actually intend to deploy these devices in anger. It serves as a great warning about the potential danger of such an attack, however. Stay sharp, and keep your office door locked this October 31st!

Creepy Halloween Doll Might Make You Betsy Wetsy

October 22, 2019 by Kristina Panos 6 Comments

If you want to terrify your neighborhood this Halloween, you might go for the old standbys like skeletons or zombies. But you don’t have to go gory to find glory. Consider the talking doll. Those things are creepy enough already, right? Well, [cabuu] says no, the doll should be animated with servos and have remote control. She should still be able to talk, just not when you expect her to.

Forget pushing on her stomach, ’cause Baby’s got a Wemos D1 mini and her own Blynk app now. A set of sliders in the app control a micro servo that animates her eyes, and another servo that twists her head from side to side. Her head doesn’t go all the way ’round, but that’s probably for the best. There are preset fright modes [cabuu] can set and forget until she springs to life via motion sensor.

We particularly like the bracket [cabuu] designed and printed that joins the eyeballs with the servo, along with his clever use of printed mate brackets to hold the servos in place within the head. If you think you can stomach it, there’s a demo video after the break. Stay tuned for total doll dissection after that as [cabuu] builds and inserts the terrifying tidbits.

We love hacks that combine innocence with insanity. Have you ever seen Thomas the Tank Engine singing Rick Astley?

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