Posts with «arduino» label

Automated Turntable For 3D Scanning

Those just starting out in 3D printing often believe that their next major purchase after the printer will be a 3D scanner. If you’re going to get something that can print a three dimensional model, why not get something that can create said models from real-world objects? But the reality is that only a small percentage ever follow through with buying the scanner; primarily because they are notoriously expensive, but also because the scanned models often require a lot of cleanup work to be usable anyway.

While this project by [Travis Antoniello] won’t make it any easier to utilize scanned 3D models, it definitely makes them cheaper to acquire. So at least that’s half the battle. Consisting primarily of a stepper motor, an Arduino, and a EasyDriver controller, this is a project you might be able to assemble from the parts bin. Assuming you’ve got a pretty decent camera in there, anyway…

The general idea is to place a platform on the stepper motor, and have the Arduino rotate it 10 degrees at a time in front of a camera on a tripod. The camera is triggered by an IR LED on one of the Arduino’s digital pins, so that it takes a picture each time the platform rotates. There are configurable values to give the object time to settle down after rotation, and a delay to give the camera time to take the picture and get ready for the next one.

Once all the pictures have been taken, they are loaded into special software to perform what’s known as photogrammetry. By compiling all of the images together, the software is able to generate a fairly accurate 3D image. It might not have the resolution to make a 1:1 copy of a broken part, but it can help shave some modeling time when working with complex objects.

We’ve previously covered the use of photogrammetry to design 3D printed accessories, as well as a slightly different take on an automated turntable a few years ago. The process is still not too common, but the barriers to giving it a try on your own are at least getting lower.

Blow out this Arduino LED candle!

LED candles can provide a nice sense of ambiance, without the inherent associated risk of fire. For better or worse, however, they don’t normally respond to air currents. 

Paul Dietz, however, shows that this kind of response is actually possible, as an LED’s forward voltage drop is affected by how well it dissipates heat due to ambient air conditions.

This means that when you puff on an LED, the resulting voltage changes can be picked up by an Arduino Uno.

LEDs are designed to emit light, but they also make surprisingly capable sensors. Using only an Arduino UNO, an LED and a resistor, we will build a hot LED anemometer that measures wind speed, and turns off the LED for two seconds when it detects you are blowing on it. You can use this to make breath controlled interfaces, or even an electronic candle that you can blow out!

How Does This Work? 

When you run current through an LED, its temperature rises. The amount of rise depends on how effectively you are cooling it. When you blow on a hot LED, the extra cooling lowers the running temperature. We can detect this because the forward voltage drop of an LED increases as it gets cooler.

The circuit is very simple and looks much like driving an LED. The only difference is that we will add an extra wire to measure the voltage drop of the LED while it is on. To work well, you want to use a very small LED (I suggest using an 0402 surface mount LED) connected by the thinnest possible wires. This will allow the LED to heat and cool very quickly, and minimize the heat lost through the wires. The voltage changes we are looking for are just millivolts – at the very edge of what can be reliably detected via the UNOs analog pins. If the LED is resting on something that conducts heat away, it may not be able to get hot enough, so it works best if it is up in the air.

As shown in the video below, he turned this concept into a novel “candle” setup, blowing his tiny 0402 SMD-format LED out over and over—like a trick birthday candle!

Arduino Blog 21 Aug 18:48

DeepWay helps the visually impaired navigate with a tap

In order to help those with visual impairments navigate streets, college student Satinder Singh has come up with an innovative solution that literally pokes the user in the right direction. 

Singh’s system, called DeepWay, uses a chest-mounted camera to take images of the road that a wearer is walking down, then feeds this information to a laptop for processing. 

If the deep learning algorithm determines that the user needs to move left or right to stay on the path, a serial signal is sent to an Arduino Uno, which in turn commands one of two servos mounted to a pair of glasses to tap the person to indicate which way to walk. Additional environmental feedback is provided through a pair of earphones.

This project is an aid to the blind. Till date there has been no technological advancement in the way the blind navigate. So I have used deep learning particularly convolutional neural networks so that they can navigate through the streets.

My project is an implementation of CNNs, and we all know that they require a large amount of training data. So the first obstruction in my way was a correclty labeled dataset of images. So I went around my college and recorded a lot of videos (of all types of roads and also off-roads). Then I wrote a basic Python script to save images from the video (I saved 1 image out of every 5 frames, because the consecutive frame are almost identical). I collected almost 10,000 such images almost 3,300 for each class (i.e. left right and center).

I made a collection of CNN architectures and trained the model. Then I evaluated the performance of all the models and chose the one with the best accuracy. I got a training accuracy of about 97%. I got roughly same accuracy for all the trained model but I realized that the model in which implemented regularization performed better on the test set.

The next problem was how can I tell the blind people in which direction to move. So I connected my Python program to an Arduino. I connected the servo motors to Arduino and fixed the servo motors to the sides of a spectacle. Using serial communication I can tell the Arduino which servo motor to move which would then press to one side of the blind person’s head and would indicate him in which direction to move.

A demo of DeepWay can be seen in the video below, while code for this open source project is available on GitHub.

Custom Split-Flap Display Is a Unique Way to Show the Weather

There’s little doubt about the charms of a split-flap display. Watching a display build up a clear, legible message by flipping cards can be mesmerizing, whether on a retro clock radio from the 70s or as part of a big arrival and departure display at an airport or train station. But a weather station with a split-flap display? That’s something you don’t see often.

We usually see projects using split-flap units harvested from some kind of commercial display, but [gabbapeople] decided to go custom and build these displays from the ground up. The frame and mechanicals for each display are made from laser-cut acrylic, as are the flip-card halves. Each cell can display a full alphanumeric character set on 36 cards, with each display driven by its own stepper. An Arduino fetches current conditions from a weather API and translates the description of the weather into a four-character code. The codes shown in the video below seem a little cryptic, but the abbreviation list posted with the project makes things a bit clearer. Bonus points if you can figure out what “HMOO” is without looking at the list.

We like the look and feel of this, but we wonder if split-flap icons might be a neat way to display weather too. It seems like it would be easy enough to do with [gabbapeople]’s detailed instructions. Or you could always look at one of the many other custom split-flap displays we’ve featured for more inspiration.

Multi-switch Useless Box Is Useless In Multiple Ways

We’ve probably all seen (and built) a useless box, in which you flip a switch that activates a servo that pops out a finger and flips the switch off. [Coffeman500] decided to take this a step further by building a useless box with multiple switches. Flip one, the finger pops out to flip it back. Flip several switches, and the finger pops out and flips each back in turn.

It’s a smart build that [coffeeman500] says is his first electronics build. The compulsively switching brain of this is an ATmega328 driving an A4988 stepper motor driver, with one stepper moving the finger mechanism and the other moving the finger along a rail to reach each switch in turn. [Coffeeman500] has released the complete plans for this wonderful waste of time, including 3D models for the box and mechanism, plus the code. Redditors are already planning bigger and more useless designs with more switches, a pursuit that we fully support.

Via [Reddit]

Hack a Day 18 Aug 06:00

Semi-automated Winder Spins Rotors for Motors

What’s your secret evil plan? Are you looking for world domination by building a machine that can truly replicate itself? Or are you just tired of winding motor rotors and other coils by hand? Either way, this automated coil winder is something you’re probably going to need.

We jest in part, but it’s true that closing the loop on self-replicating machines means being able to make things like motors. And for either brushed or brushless motors, that means turning spools of wire into coils of some sort. [Mr Innovative]’s winder uses a 3D-printed tube to spin magnet wire around a rotor core. A stepper motor turns the spinner arm a specified number of times, pausing at the end so the operator can move the wire to make room for the next loop. The rotor then spins to the next position on its own stepper motor, and the winding continues. That manual step needs attention to make this a fully automated system, and we think the tension of the wire needs to be addressed so the windings are a bit tighter. But it’s still a nice start, and it gives us some ideas for related coil-winding projects.

Of course, not every motor needs wound coils. After all, brushless PCB motors with etched coils are a thing.

Hack a Day 17 Aug 16:30

Build a 4-button arcade game out of LEGO

If your kids (or you) have somehow gotten tired of playing with LEGO bricks, Lenka Design Workshop has a great way for you to breathe new life into this unused pile. 

Their game enclosure consists of a 32×32 LEGO baseplate, along with walls made of blocks to support a clear acrylic cover. This in turn holds four large arcade buttons for gameplay control. Five games are currently implemented to run on the game’s Arduino, with light and sound feedback.

We decided to recycle the unwanted Lego bricks and created an arcade game.

The code has been written in such a way that it doesn’t have dependencies and will compile on any Arduino board. And of course the games have been intensively tested by our kids.

How is this game different from many others that have been published before?

First of all, there are 5 games built into it:

  • Memory Game (“Simon-Says”-like, similar to Touch Me game)
  • Reaction game (similar to Whack-a-Mole game)
  • Contest/Competition game (for 2-4 players)
  • Melody Game (Push and Play free mode for toddlers and smaller ones)
  • War game (for 2-4 adults)

Secondly, it has a great design (from our perspective) and can be easily repeated.

And thirdly, it is earth-friendly because it allows you to recycle the plastic.

You can see a short demo of the system in the video below, or check out the project write-up for more info. 

Arduino Blog 17 Aug 15:58

Make your own soda fountain out of cardboard

If you’re ever wanted to make something awesome, but thought that you just didn’t have the right tools to do so, this soda fountain by “The Wrench” could provide the needed inspiration. 

The project uses an Arduino Nano to control a small air pump via a relay, which turns on when a glass is the correct dispensing position. This pushes air into a sealed soda bottle, and soda is pushed out of another tube to equalize the pressure.

It’s a certainly a neat trick. Given its frame made out of cardboard stuck together with hot glue, the raw materials are very easy to obtain and dispose of when needed. The build process is explained in the video below, while the circuit diagram and Arduino code can be found here.

An Arduino-controlled turntable for 3D scanning

Many DSLR cameras can be operated with a simple infrared signal, making them perfect targets for Arduino control. Travis Antoniello took advantage of this with his brilliantly simple 3D scanning rig.

Electronics are handled by an Arduino Uno, which commands a stepper motor to rotate a scanning platform 10 degrees per photo. After rotation, it stops for a set amount of time to let scanned objects settle, and triggers the camera, a Nikon D3200, via an infrared LED. It then repeats this process over and over until a full set of photos is taken. 

Code for the build can be found on GitHub, and the device’s 3D-printed components are available on Thingiverse. The project video seen here gives a good overview of how it works, and the scanned object on display just after 2:30 looks absolutely brilliant.

Turn the pages on your Kindle remotely with Arduino

As seen here, Alex Mikes enjoys reading his Kindle in bed at night, but prefers to use a stand rather than hold it in his hands. The one disadvantage to this is that one normally has to lift his or her hand up to change pages. Thanks to a clever bit of engineering, Mikes only has to press the button on a small RF remote, signaling an Arduino Nano-based robot to press it for him.

The device uses a micro servo motor to actuate the fake finger, which swings into the correct position to advance pages on command. A 3D-printed frame holds everything in place, and in order to properly control his Kindle’s capacitive touchscreen, a wire is wrapped inside the stylus tip and connected to the circuit ground. 

Not since Rick and Morty’s butter-passing robot has there been a more hyper-specific, purpose-built device than perhaps Alex Mikes’ automatic Kindle page turner. Instead of having to raise his arm to tap the edge of the screen while reading in bed, a simple click of a wireless remote makes the attached contraption do all of that hard work for him.

More photos of the project are up on Imgur.