Getting the finishing details on a Halloween costume completed is the key to impressing friends and strangers alike on the trick-or-treat rounds. Especially when it comes to things like props, these details can push a good Halloween costume to great with the right touches. [Jonathan]’s friend’s daughter will be well ahead of the game thanks to these additions to a toy guitar which is part of her costume this year.

The toy guitar as it was when it arrived had the capability to play a few lackluster sound effects. The goal here was to get it to play a much more impressive set of songs instead, and to make a couple upgrades along the way as well. To that end, [Jonathan] started by dismantling the toy and investigating the PCBs for potential reuse. He decided to keep the buttons in the neck of the guitar despite their non-standard wiring configuration, but toss out the main board in favor of an ESP32. The ESP32 is tasked with reading the buttons, playing a corresponding song loaded on an SD card, and handling the digital to analog conversion when sending it out to be played on the speaker.

The project doesn’t stop there, though. [Jonathan] also did some custom mixing for the songs to account for the lack of stereo sound and a working volume knob, plus he used the ESP32’s wireless capabilities to set the guitar up as a local file server so that songs can be sent to and from the device without any wires. He also released the source code on the project’s GitHub page for anyone looking to use any parts of this project. Don’t forget there’s a Halloween contest going on right now, so be sure to submit the final version of projects like these there!

If you were a youth in the 90s, odds are good that you were a part of the virtual pet fad and had your very own beeping Tamagotchi to take care of, much to the chagrin of your parents. Without the appropriate amout of attention each day, the pets could become sick or die, and the only way to prevent this was to sneak the toy into class and hope it didn’t make too much noise. A more responsible solution to this problem would have been to build something to take care of your virtual pet for you.

An art installation in Moscow is using an Arduino to take care of five Tamagotchis simultaneously in a virtal farm of sorts. The system is directly wired to all five toys to simulate button presses, and behaves ideally to make sure all the digital animals are properly cared for. Although no source code is provided, it seems to have some sort of machine learning capability in order to best care for all five pets at the same time. The system also prints out the statuses on a thermal printer, so you can check up on the history of all of the animals.

The popularity of these toys leads to a lot of in-depth investigation of what really goes on inside them, and a lot of other modifications to the original units and to the software. You can get a complete ROM dump of one, build a giant one, or even take care of an infinite number of them. Who would have thought a passing fad would have so much hackability?

Not all projects are made equal. Some are designed to solve a problem while others are just for fun. Entering the ranks of the most useless machines is a project by [Vladimir Mariano] who created the 3D Printed Dancing Springs. It is a step up from 3D printing a custom slinky and will make a fine edition to any maker bench.

The project uses 3D printed coils made of transparent material that is mounted atop geared platforms and attached to a fixed frame. The gears are driven by a servo motor. The motor rotates the gears and the result is a distortion in the spring. This distortion is what the dancing is all about. To add to the effect, [Vladimir Mariano] uses RGB LEDs controlled by an ATmega32u4.

You can’t dance without music. So [Vladimir] added a MEMs microphone to pick up noise levels which are used to control the servo and lights. The code, STL files and build instructions are available on the website for you to follow along. If lights and sound are your things, you must check out the LED Illuminated Isomorphic Keyboard from the past.

We hate to break it to [Rob Cai], but he’s built a VGA drawing toy, not an Etch-a-Sketch. How do we know? Simple, Etch-a-Sketch is a registered trademark. Regardless, his project shows how an Arduino can drive a VGA monitor using the VGAx library. Sure, you can only do four colors with a 120×60 resolution, but on the other hand, it requires almost no hardware other than the Arduino (you do need four resistors).

The hardware includes two pots and with the right firmware, it can also play pong, if you don’t want to give bent your artistic side. You can see videos of both the art toy and the pong game, below.

Because the device started as a pong game, [Rob’s] version has two boxes, each with a pot and a button. Of course, if you were really building it just for the drawing toy, you’d probably put it all in a box. Maybe even a red box. If we were building it, we’d be tempted to put a tilt sensor or an accelerometer in the box so you could shake it to erase the picture. Just saying.

If you want 640×480 resolution from an Arduino, it can be done, but it takes more hardware. If you were trying to get a kid interested in Arduino, you could do worse than start with two projects with video that are fun, use a handful of easy-to-source parts, and shares hardware. Then again, if you are in the “go big or go home” camp, we’d redirect to this pong game, instead.

[Mathieu] wrote in with his laser target practice game. It’s not the most amazing hack in the history of hackery, but it’s an excellent example of the type of simple and fun things you can do with just a little bit of microcontrollering.

First off, the gun is a broken toy gun that used to shoot something other than red collimated light beams. The Arduino knockoff inside reacts to a trigger pull and fires the laser for around 200 milliseconds. The gun also has a “gas gauge” that fills up with repeated shots and cools down over time. And therein lies the game — a simple race to ten, where each player only has a fixed number of shots over time.

The targets are simply a light sensor, scorekeeping LED display, and a buzzer that builds tension by beeping at you as the countdown timer ticks down. The bodies are made out of 3D-printed corners that connect some of [Mathieu]’s excess wooden goat-cheese lids.

All the code is up on GitHub so you can make your own with stuff that you’ve got lying around the house. The “gun” can be anything that you can embed a laser in that makes it aimable. Good clean fun!

[Markus Gritsch] and his son had a fun Sunday putting together a little toy airboat from a kit. They fired it up and it occurred to [Markus] that it was pretty lame. It went forward and sometimes sideward when a stray current influenced its trajectory, but it had no will of its own.

The boat was extracted from water before it could wander off and find itself lost forever. [Markus] did a mental inventory of his hacker bench and decided this was a quickly rectified design shortcoming. He applied a cheap knock-off arduino, equally cheap nRF24L01+ chip of dubious parentage, and their equivalent hobby servo to the problem.

Some quick coding later, assisted by prior work from other RC enthusiasts, the little boat was significantly upgraded. Now the boat could be brought back to shore using any R/C controller that supported the, “Bayang,” protocol. He wouldn’t have to face the future in which he’d have to explain to his son that the boat, like treacherous helium balloons, was just gone. Video after the break.

Primary image

Otto was inspired by another robot instructable BoB the BiPed and programmed using code from another open source biped robot called Zowi.

CC-BY-SA

Otto's differences are in the assembled size (11cm x 7cm x12cm), cleaner integration of components and expressions.

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Since most kids have already mastered the art of iPad password cracking and in-app purchasing, we should probably give them something productive to do. The arduino-based Vortex from DFRobot is a STEM-reinforcing plaything that can help kids learn to code. It comes with preinstalled programs, so you can have fun racing, bumping and spinning right out of the box, but the variations are endless. Open-source hardware and the WhenDo app's graphical programming interface mean the sky's the limit with Vortex. These little bots are laden with proximity and ground sensors, LEDs and speakers — not to mention all the add-ons — to help bring them to life. DFRobot has given us a pair of two-robot packs for a couple lucky Engadget readers this week. All you need to do is head to the Rafflecopter widget below for up to three chances at winning this hackable robot duo.

Since most kids have already mastered the art of iPad password cracking and in-app purchasing, we should probably give them something productive to do. The arduino-based Vortex from DFRobot is a STEM-reinforcing plaything that can help kids learn to code. It comes with preinstalled programs, so you can have fun racing, bumping and spinning right out of the box, but the variations are endless. Open-source hardware and the WhenDo app's graphical programming interface mean the sky's the limit with Vortex. These little bots are laden with proximity and ground sensors, LEDs and speakers — not to mention all the optional add-ons — to help bring them to life. DFRobot has given us a pair of two-robot packs for a couple lucky Engadget readers this week. All you need to do is head to the Rafflecopter widget below for up to three chances at winning this hackable robot duo.

Since most kids have already mastered the art of iPad password cracking and in-app purchasing, we should probably give them something productive to do. The arduino-based Vortex from DFRobot is a STEM-reinforcing plaything that can help kids learn to code. It comes with preinstalled programs, so you can have fun racing, bumping and spinning right out of the box, but the variations are endless. Open-source hardware and the WhenDo app's graphical programming interface mean the sky's the limit with Vortex. These little bots are laden with proximity and ground sensors, LEDs and speakers — not to mention all the optional add-ons — to help bring them to life. DFRobot has given us a pair of two-robot packs for a couple lucky Engadget readers this week. All you need to do is head to the Rafflecopter widget below for up to three chances at winning this hackable robot duo.