Author: Zoe Skyforest

3786 Articles

This Air Particulate Sensor Can Also Check Your Pulse Rate

March 26, 2024 by 7 Comments

The MAX30105 is an optical sensor capable of a great many things. It can sense particulate matter in the air, or pick up the blinking of an eye. Or, you can use it as a rudimentary way to measure your heart rate and blood oxygen levels. It’s by no means a medical grade tool, but this build from [Taste The Code] is still quite impressive.

The MAX30105 contains red, green, and infrared LEDs, and a very sensitive light detector. The way it works is by turning on its different LEDs, and then carefully measuring what gets reflected back. In this way it can measure particles in the air,  such as smoke, which is actually what it was designed for originally. Or, if you press your finger up against it, it can measure the light coming back from your blood and determine its oxygenation level. By detecting the variation in the light over time, it’s possible to pick up your pulse, too.

Getting this data out of the sensor is remarkably easy. One need only hook it up to a suitable microcontroller like the ESP8266 and use the MAX3010X library to talk to it. [Taste The Code] did exactly that, and also hooked up a screen for displaying the captured data. Alternatively, if you want the raw data from the sensor, you can get that too.

It should be noted that this build was done for educational purposes only. You shouldn’t rely on a simple DIY device for gathering useful medical data; there are reasons the real gear is so expensive, after all. We’ve looked at this sensor before, too, not long after it first hit the market. Continue reading “This Air Particulate Sensor Can Also Check Your Pulse Rate” →

AxxSolder 3.0 Now Takes USB Power Delivery

March 25, 2024 by 12 Comments

If you’re big into the soldering iron scene, you’ve probably heard of the AxxSolder project. Now, it’s been updated with a whole host of nifty new features. It’s AxxSolder 3.0!

If you’re not intimately familiar with AxxSolder, it’s an open-source iron design based around the popular JBC soldering iron tips. Relying on the STM32G431CBT6 to run the show, it comes in two versions—a lightweight portable design, and a desktop version based around the JBC ADS soldering iron stand. So far, so familiar.

The new 3.0 version adds new functionality, however. Where the previous model ran off any old DC power source from 9 to 26 volts, the new version can run off a USB Power Delivery supply. Thus, you can grab any old USB-PD device, like a laptop charger, and run your iron off that.

The new version also uses a larger color TFT screen with some buttons added on as an improved user interface. Thermal performance is improved, and it’s additionally capable of measuring the current draw by the tip, so you can monitor the performance of the iron in great detail.

We’ve featured the AxxSolder project previously, too, along with some other great soldering iron projects. If you reckon you’ve just designed the hottest new soldering tool yourself, let us know about it!

Dodge, The Weird Tripod Robot

March 25, 2024 by 13 Comments

[hannu_hell] created Dodge as a “novel design of tripod.” It’s a small robotic device quite unlike anything else we’ve seen of late. It’s intended to be a self-mobile camera platform that can move itself around to capture footage as needed.

Dodge is essentially a two-legged robot with a large flat “foot” in the center. When stationary, it rests on this flat foot. When it needs to move, it can raise this center foot and rest on its two outside legs. If Dodge needs to move, it can crab back and forth in a line with these two legs. If it wants to turn, it can return to resting on its center foot, and pivot about its central axis. It can thus rotate itself and use its two outer legs to move further as needed.

Dodge does all this while carrying an ESP32 Cam module. The idea is that it’s a small mobile tripod platform with a live camera feed. It reminds us of various small monitoring robots from cartoons and anime.

Ultimately, it’s an interesting take on robot locomotion. Rather than walking with two legs or four legs and dynamic stability, it takes full advantage of static stability instead.

We’ve seen some wild roboticized camera rigs over the years. Video after the break.

Continue reading “Dodge, The Weird Tripod Robot” →

Building A Tiny Organic Swimming Pool With Natural Filtering

March 24, 2024 by 19 Comments

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.

Continue reading “Building A Tiny Organic Swimming Pool With Natural Filtering” →

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

March 24, 2024 by 14 Comments

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

March 23, 2024 by 3 Comments

[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

March 23, 2024 by 9 Comments

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.

Continue reading “Building A Tribute Version Of Mattel’s VertiBird Toy” →