Building A Tiny Organic Swimming Pool With Natural Filtering

When we think of swimming pools, we typically think of large fiberglass, plastic, or concrete constructions full of pristine, clear water. They’re usually maintained in this state with the regular addition of chlorine or other chemical. These kill biological stuff and help filter out dirt and other detritus. However,  [David] likes to do things differently, as he demonstrates with a tiny plunge pool built inside his greenhouse.

The basic construction starts with digging a hole and building up a wall with concrete and bricks. There’s nothing particularly controversial there. It’s roughly 2 meters by 3 meters by 0.8 meters deep. To help the pool maintain heat, there’s a layer of foam insulation in the bottom, while the water is held inside a black liner.

Rather than traditional chemical methods, however, [David] relies on organic methods to maintain the pool. He explains how he uses an aquarium pump to create a “bubble filtered” pool that draws water through a gravel bed to maintain it and keep it clear. It’s a very natural setup, with multiple plants in the water to make it as organic as can be. It’s the kind of thing you’d expect to see at a luxury island resort, but [David’s] got one right in his very own greenhouse.  [David] explains the organic filtering concept in greater detail on his website.

We’ve featured some pool hacks before, too, though more traditional ones than this. Video after the break.

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It’s Never Been Easier To Build A WiFi-Controlled RC Car

Today, wireless-enabled microcontrollers are everywhere and can be had for just a few bucks. You can use them to build all kinds of connected projects more cheaply than ever before. [ROBO HUB] demonstrates this well with an incredibly simple WiFi-controlled RC car build.

The build is based around an NodeMCU ESP8266 microcontroller, paired with an L293D motor driver. This lets the microcontroller drive brushed DC motors for differential drive. Power is courtesy of three 18650 lithium-ion batteries. These parts are assembled into a 3D-printed car of sorts with four wheels. The drivetrain is rather odd, with gear motors installed on the two front wheels, and simple brushed DC motors installed on the two rear wheels. The motors on each side are paired together so the vehicle has tank-style steering.

Meanwhile, the ESP8266 is programmed so it can be controlled via a smartphone app. The touchscreen controls are not as elegant as toy RC cars of years past, but it’s pretty good for a cheap DIY build.

It’s a fairly simple project and one that any high-school student could follow along to learn something. Projects like these can be a great way to learn about everything from mechanics to electronics and even basic programming. It may not be complicated, but that makes it a great learning tool. We see a ton of projects like this on the regular, and every time they’re built, somebody is picking up some new skills.

We’ve been talking about WiFi-controlled RC cars for a long time. Way back when it was nowhere near this easy. Video after the break. Continue reading “It’s Never Been Easier To Build A WiFi-Controlled RC Car”

Interactive Cake Takes Your Picture

[Abigail] is a confectionery roboticist, and [Hazal] is a developer advocate at a robotics company. The two met recently and decided to collaborate on a smart cake, with amusing results.

The resulting cake not only looks like a camera it also has a camera inside. When the camera detects people in its field of view, a NeoPixel is lit up in green to signal it’s spotted something. If you so desire, you can then hit a button and the cakera (cake-camera, keep up) will take your photo.

The cake itself looks to be a sponge of some sort with fondant used to create the camera housing and a surround for the preview screen. Inside the cake is a standard photo-booth style setup built with a Raspberry Pi. The Pi is responsible for taking photos with a USB cam. It does this when instructed via an arcade button acting as the shutter release. After taking a photo, the Pi prints out a receipt with an Adafruit thermal printer. This provides the user a number they can use to receive their photo afterward.

We’ve seen some neat cakes before, too. If you’ve been hacking on cakes, either edible or theoretical, we might just want to know more. Drop us a line!

Building A Tribute Version Of Mattel’s VertiBird Toy

Mattel had a ton of hit toys in the 20th century. In the early 1970s, the VertiBird was one of them, letting kids pretend to fly a helicopter in circles on their loungeroom floor. An original VertiBird can be hard to come by these days, but what if you could make your own? Well, [Gord Payne] did just that!

The design of the VertiBird is simple enough that it’s easy to replicate with a 3D printer. It features a helicopter on a rod that spins around a central base. The helicopter itself has a rotor powered by a motor, with variable speed control to vary the lift it produces. The helicopter’s flight can be controlled in a circular path around the base using throttle and pitch controls. [Gord’s] build was inspired by an earlier replica from [Luke J Barker] and borrows some parts from it, too. However, this build uses an ATTiny85 microcontroller to control the helicopter’s tilt and direction with the aid of a servo.

It’s great to see this classic toy recreated from scratch, particularly given the enormous cost of original sets these days. It’s also great fun to watch [Gord] execute an aerial rescue with the toy, too. Video after the break.

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Wico Boss Joystick Modded To Use Cherry MX Keyboard Switches

The Wico Boss joystick was one of the better designs of the 1980s. Yours truly had one, and put it through many brutal hours of Amiga-based gameplay. [Drygol] was recently asked if he could alter some of these sticks to be even clickier than stock, and jumped at the change to do some modding.

[Drygol]’s idea was to swap out the original microswitches in the sticks for keyboard switches instead. In particular, the idea was to use the Cherry MX Blues which have a particularly nice click to them. But this wasn’t just going to be a straight swap. Instead, since the hardware was retro and preservation was desired, the modification had to be reversible.

The result was a drop-in 3D-printed bracket that holds four Cherry switches around the joystick’s central bauble. Thus, when the stick is moved, it actuates the keyboard switches with a satisfying click. A 12mm tactile switch was also installed in the base to be activated by the fire button. Then, it was a simple matter of  tidying up some of the sticks during reassembly and wiring up the original cables to the new switches.

It’s a neat way to give an old-fashioned digital joystick a new lease on life. This would be a particularly great mod for tired sticks with worn out microswitches, too. Hilarious archaic marketing video after the break. They really are whacko for Wico.

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YouTuber Builds Onewheel With Tracks Instead And It’s Not Great

The one-wheel is a triumph of modern sensor and control technology. That made it possible to sense the acceleration and position of a platform with a single wheel, and to control that single wheel to keep the platform stable and level, even in motion. [RCLifeOn] has now taken that same concept and made it more hilarious by swapping out the wheel for a track.

The original idea was to build an electric snowboard, which worked just okay. Then, it morphed into a tank-based one-wheel instead. It’s a bit silly on the face of it, because a track is more stable than a wheel. That’s because instead of balancing on a small flattened spot of a tire, it’s got a wider, flatter footprint. But that means there’s no real need for balancing control as the track is statically stable.

The 3D-printed track assembly is driven by a powerful brushless motor via a gear drive for additional torque. Riding it is difficult on 48-volt power as it easily throws [RCLifeOn] off the board with its raw torque. At 24 volts, however, it was just barely ridable with some practice. But it was ultimately pretty terrible. It was either not moving at all, or jerking so hard that it was impossible to stay on the thing.

We’d like to see this concept tried again, perhaps with a rubber track and a more refined controller. Video after the break.

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Build Yourself A Vacuum Tube VU Meter

Volume unit (VU) meters are cool — it’s an undeniable fact. For some reason, humans just dig lights that flash along with sounds. You can build a VU meter using LEDs, or bulbs if you’re trapped in 1972. Or, you could use special vacuum tubes. [mircemk] did just that in their latest VU meter project.

The 6E2 vacuum tube is the part for the job in this case. You might think a specialist tube like this is expensive, but they can be had for just a few dollars from online retailers. They were often used as tuning indicators, but here, they’re used as a responsive VU meter instead. However, instead of a single bar going up and down, you get a pair of bars that raise to meet in the middle.

[mircemk] explains all the circuitry required to drive the tubes, and how to hook them up to create a two-channel stereo VU meter. The final circuit largely relies on a transistor, a diode, some passive components, and a DC-DC boost supply to generate 250 V for the tubes.

The final result looks pretty neat, particularly as it’s built into an old-school blue project box. We’ve seen similar projects from [mircemk] before, too. Continue reading “Build Yourself A Vacuum Tube VU Meter”