OpenCV Turret Tracks Motion, Busts Airsoft Pellets

In the eternal struggle for office dominance, the motion-tracking Airsoft/Nerf/whatever, the autonomous turret seems to be the nuclear option. [Aaron] and [Davis] built a motion-tracking turret that uses openCV to detect movement, before hitting a relay to trigger the gun.

There’s a Raspberry Pi controlling a Logitech C210 Pi-compatible webcam, with a stepper hat for the Pi controlling two NEMA steppers that aim the gun. The design is simple but elegant, with a rotating base and an assembly that raises and lowers the weapon.

The openCV intrigues us. We want to see a openCV-powered turret with color detection, so your own team doesn’t get blasted along with your hapless enemies. Or if guarding your cubicle, how about a little openCV facial recognition?

If you want to take a stab at your own, [Aaron] and [Davis] show how they built their project in their page and their Python script can be found on GitHub.  Otherwise, check out the Counter Strike Airsoft robot, the Airsoft sentry gun, and the Nerf turret powered by Slack we published previously. Continue reading “OpenCV Turret Tracks Motion, Busts Airsoft Pellets”

Monster Mindstorms Delta Bot Delicately Picks Candy

A group of embedded developers from Sioux Embedded Systems in Eindhoven, the Netherlands, wanted to get experience working on Microsoft .Net. To make it fun they made it their project to produce a LEGO train with visitors at LEGO World, the official LEGO convention in the Netherlands. The team developed an application in C# to fully automate the train, with Mindstorms NXT and EV3 bricks as well as LEGO Power Functions motors controlling everything.

The train project carries a simple premise: the visitor chooses one of four colors, and the train goes and picks up a piece of simulated candy with the matching color. Called on Track, the project has produced a new train every year since 2012 with improvement goals in place to add features with every version. Ironically, the least interesting part of the setup is the actual train and track. The team’s creativity comes to the fore in two areas of the project: the method by which the candy color is selected, and the assembly that dispenses the correct color into the train car.

Team member [Hans Odenthal] has built candy-grabbers for various years’ trains. He learned about the ABB FlexPicker and this year decided to build a delta robot for the layout. It consists of huge girders constructed from 5×9 and 5×11 Technic beam frames held together with more Technic beams and hundreds of connector pegs. The three arms each move on a pair of turntables which are geared down to provide as much torque as possible — the fake candy pieces are light, but the arms themselves weigh a lot. [Hans] ended up revamping the gearboxes to up the ratio from 1:5 to 1:25.

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Controlling A Micro Helicopter with a PS2 Controller

The Syma S107G is a venerable stalwart of the micro helicopter market. Affordable, robust, and ubiquitous, the S107G relies on infrared to receive its control signals. Emboldened by the prior work of others, [Robert] set out to control his with a Playstation 2 controller.

In this project, [Robert] is standing on the shoulders of giants, so to speak – we’ve seen others reverse engineer the S107G’s communications protocol before. [Robert] combined the efforts of several others to understand how to send commands to the helicopter, including use of two separate channels for controlling two at once.

With the knowledge of the necessary protocols, it’s then a matter of hooking up 3 LEDs in a somewhat unconventional series arrangement with a 9 volt supply, to be switched by an Arduino hooked up to a computer. A Javascript application running on the computer reads the state of a Playstation 2 controller, and spits it out over serial to the Arduino, which flashes the LEDs.

It’s not the neatest, most lightweight way of building a new controller for your remote control toy, but it does show how quickly one can throw together a project in a weekend by combining modern hardware and software tools. Plus, it’s a great learning experience on a platform that’s been experimented with the world over.

World’s Largest Super Soaker is Dangerously Good Clean Fun

Running around while dousing each other with Super Soakers and screaming in delight is de rigueur on suburban lawns on hot summer days, but if you build this giant replica of a Super Soaker that can double as a pressure washer, you might have the upper edge on the neighborhood gang.

You may remember [Mark Rober] from such projects as his bullseye-catching dart board and his previous entry in the awesome uncle of the year awards, the fully automatic snowball gun. We’re not entirely sure that this seven-foot long replica of the original Super Soaker will win him any uncle or neighbor plaudits, given that it the stream it produces is not far off of what a pressure washer can manage and can literally slice a watermelon in half. Fortunately, [Mark] included swappable nozzles to reduce the pressure enough that relatively safe dousing is still on the table. The housing is a pretty accurate plywood and foam replica of the original toy, but the mechanism is beefed up considerably — a pair of nitrogen tanks, some regulators, and a solenoid valve. See the gun in all its window-smashing, kid-soaking glory in the video after the break.

We realize [Mark]’s build is just a fun way to beat the heat, but it gives us a few ideas for more practical uses. Maybe a DIY water-jet cutter that’s not built around a pressure washer?

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Electric Skateboard Rocks the Giant LEGO

[James Bruton] built an electric skateboard out of oversized LEGO bricks he printed himself, and equipped the board with an excellent re-creation of a classic motor.

He began by downloading brick, gear, and pulley designs from Thingiverse and printing them up five times their normal size, taking 600 hours. The deck consists of 8M Technic bricks lengthwise and 4M bricks crosswise, with plates covering top. There’s even a monster 5×6 plate that’s clearly courtesy of a parametric brick design because you won’t find that configuration among LEGO’s official parts.

The coolest part of the project is probably [James]’ re-creation of an old school LEGO motor. He sized up a 6216M Technic motor originally rated for 4.5V swapping in a 1.5 kW, 24V motor controlled by a 120A ESC and powered pair of Turnigy 5000mAh LiPos wired in series.

[James] had to design his own casing in Blender because couldn’t find a file for the original LEGO part—pro tip for the future, LDraw has the 6216 design and it can be dropped into Blender.

Another nice touch are the wheels, with hubs based off upsized 40-tooth Technic gears with Ninjaflex tires that weigh half-a-kilo each and took 32 hours apiece to print.

We’ve published a lot of [James] ‘ work, including his BB-8 model and some of his other Star Wars models. Continue reading “Electric Skateboard Rocks the Giant LEGO”

Robot Car Follows Wherever You Go

Having a pet can really make a difference to your happiness at the end of the day, but they’re also a lot of work. This project by [Ioannis Stoltidis] does something similar — minus all the responsibility. The Smart Car Follower Project is designed to track people using Bluetooth and IR and follow them around from room to room.

Submitted as part of a Master’s thesis, this project hacks a toy car and uses a key chain transmitter that sends the tracking signals. A Raspberry Pi 3 combines the Bluetooth RSSI and IR signals to make create an estimate of the position of the beacon. Arduinos facilitate the IR signaling as well as the motor control allowing the robot to chase the user around like a puppy. The whole thing also comes with obstacle avoidance using ultrasonic sensors on all sides which are good if you have a lot of furniture in the house.

You can also choose to go manual-mode and drive it around the block using a PC and gamepad. A webcam connected to the onboard computer allows a first person view of the vehicle by sending the video feed over wifi to a PC application. OpenCV is used to create the final GUI which allows you to see and control the project remotely. The source code is available for download for anyone who wants to replicate the project. Check out the video of it in action below.

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Mindstorms Morse Key Writes to Drawbot

[Jason Allemann] built a Mindstorms Telegraph Machine that packs so many cool details that HaD is about to have a fit.

First off, It’s a drawbot able to write letters, a difficult feat given a lack of native stepper motors and the limited gear options for Mindstorms.  Trying to draw letters with servos typically makes for some ugly letters. And how does the drawbot know what to write? You code them in with Morse code. The second video after the break shows [Jason]’s setup. He has a Mindstorms touch sensor with a LEGO Morse key attached to it. He simply taps on the key and the EV3 Intelligent Brick interprets his dots and dashes and translates them into letters.

Next off, [Jason]’s printer is built using one EV3 set. It’s one thing to build a cool Mindstorms robot with whatever you have in your parts bin, but the gold standard is to make a project that can be built with only one EV3 set. That way, anyone with the set can build the project. Precious few really cool projects can be built with just one set–[David Gilday]’s MindCub3r Rubik’s cube solver comes to mind. Dude, this is another one.

Last off, [Jason] breaks down how to build it, providing full LDraw building steps and EV3 code on his site. Even better, he shows how to supersize the project by adding a second EV3 brick, which can connect to the drawbot’s EV3 brick via bluetooth and serve as a standalone CW key. He shows off this part in the second video.

Icing on the cake, [Jason] even built a Morse reference book, done appropriately in 100% LEGO.

Hackaday loves innovative LEGO projects, like this game-playing robot and this LEGO exoskeleton.

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