Posts with «stepper motor» label

A Command-Line Stepper Library with All the Frills

When you already know exactly where and how you’d like your motor to behave, a code-compile-flash-run-debug cycle can work just fine. But if you want to play around with a stepper motor, there’s nothing like a live interface. [BrendaEM]’s RDL is a generic stepper motor driver environment that you can flash into an Arduino. RDL talks to your computer or cell phone over serial, and can command a stepper-driver IC to move the motor in three modes: rotary, divisions of a circle, and linear. (Hence the acronumical name.) Best of all, the entire system is interactive. Have a peek at the video below.

The software has quite a range of capabilities. Typing “?” gets you a list of commands, typing “@” tells you where the motor thinks it is, and “h” moves the motor back to its home position. Rotating by turns, degrees, or to a particular position are simple. It can also read from an analog joystick, which will control the rotation speed forward and backward in real time.

Division mode carves the pie up into a number of slices, and the motor spins to these particular locations. Twelve, or sixty, divisions gives you a clock, for instance. Acceleration and deceleration profiles are built in, but tweakable. You can change microstepping on the fly, and tweak many parameters of the drive, and then save all of the results to EEPROM. If you’re playing around with a new motor, and don’t know how quickly it can accelerate, or what speeds it’s capable of, nothing beats playing around with it interactively.

Right now, there’s not much documentation aside from the code itself and the attached video, but actually that looks like all you’d need to get started. So if you’re looking to replicate Hackaday’s [Moritz Walter]’s excellent stepper-driver shootout, a tool like this is just the ticket.

Filed under: misc hacks

Cheap Dual Mirror Laser Projector

[Stanley] wanted to make a laser projector but all he could find online were one’s using expensive galvanometer scanners. So instead he came up with his own solution that is to be admired for its simplicity and its adaptation of what he could find.

At its heart is an Arduino Uno and an Adafruit Motor Shield v2. The green laser is turned on and off by the Arduino through a transistor. But the part that makes this really a fun machine to watch at work are the two stepper motors and two mirrors that reflect the laser in the X and Y directions. The mirrors are rectangles cut from a hard disk platter, which if you’ve ever seen one, is very reflective. The servos tilt the mirrors at high speed, fast enough to make the resulting projection on the wall appear almost a solid shape, depending on the image.

He’s even written a Windows application (in C#) for remotely controlling the projector through bluetooth. From its interface you can select from around sixteen predefined shapes, including a what looks like a cat head, a heart, a person and various geometric objects and line configurations.

There is a sort of curving of the lines wherever the image consists of two lines forming an angle, as if the steppers are having trouble with momentum, but that’s probably to be expected given that they’re steppers controlling relatively large mirrors. Or maybe it’s due to twist in the connection between motor shaft and mirror? Check out the video after the break and let us know what you think.

The video’s in three parts: looking at the laser beams in action as you’d see them on a dance floor, then watching the projected images while looking at an insert of the Windows application, and then watching the steppers and mirror doing their rapid movements.

As for the expensive galvanometer scanners we mentioned above, check out this impressive laser projector that uses them. Another method is to use a spinning wheel with mirrors set to different angles, like this one that draws a marquee using a pill box as the wheel. And how about one with no mirrors at all, instead attaching the laser directly to servo motors, though that one does take longer to draw.


Filed under: laser hacks

Litter Basket Automation

Sometimes the technology part of a project isn’t the hard part. It is having an idea for something both useful and doable. Sure, a robot butler that would do your cleaning and laundry would be useful, but might be out of reach for most of us. On the other hand, there’s only so many use cases for another blinking LED.

[Martinhui] knows how to use an ultrasonic sensor with an Arduino. Driving a motor isn’t that hard, either. The question is: what do you do with that? [Martin’s] answer: Automate a trash can. You can see a video of the result, below.

You can find commercial versions of this, of course, but what fun is that? The can is a bit small, but a larger motor or a different mechanical design could scale it up easily.

As robotic trash cans go, this isn’t that ambitious, but it is highly doable. If only it connected to the Internet.

Filed under: Arduino Hacks

Scissors Make Great Automatic Cable Cutters

The team at [2PrintBeta] required a bunch of cables, heat shrink, and braid to be cut for their customers. They looked into an industrial cable cutter, but decided the price was a little too high, so they decided to make their own. They had a bunch of ideas for cutting: Using a razor blade?  Or a Dremel with a cutting wheel? What they came up with was a DIY cable cutter that uses a pair of scissors, a pair of stepper motors, a pair of 3D printed wheels and an Arduino.

The first thing the team had to do was to mount the scissors so they would cut reliably. One of the stepper motors was attached to a drive wheel that had a bolt mounted on it. This went through one of the scissors’ handles, the other handle was held in place on the machine using screws. The second stepper motor was used to rotate the wheels that drives the cable through to the correct length. [2PrintBeta] used a BAM&DICE shield and two DICE-STK stepper motor drivers on an Arduino Mega to control the cutter.

The [2PrintBeta] team are pretty good at doing things themselves, as we’ve seen previously with their DIY plastic bender. And again, with this automatic cable cutter, they’ve seen a need and resolved it using the things at their disposal and some DIY ingenuity.

Filed under: Microcontrollers, tool hacks

Simple Clock is Great Stepper Motor Project

You’d think that we’ve posted every possible clock here at Hackaday. It turns out that we haven’t. But we have seen enough that we’ve started to categorize clock builds in our minds. There are the accuracy clocks which strive to get every microsecond just right, the bizzaro clocks that aim for most unique mechanism, and then there are “hello world” clocks that make a great introduction to building stuff.

Today, we’re looking at a nice “hello world” clock. [electronics for everyone]’s build uses a stepper motor and a large labelled wheel that rotates relative to a fixed pointer. Roll the wheel, and the time changes. It looks tidy, it’s cyclical by design, and it’s a no-stress way to get your feet wet driving stepper motors. And it comes with a video, embedded below.

The clock is driven by the ubiquitous 28BYJ-48 stepper motors that can be found on eBay for a few bucks. They don’t have much torque, but all they have to do here is turn a cardboard disk. It’s the perfect match.

There is one caveat with these motors, though: they don’t have an integral number of steps per turn. If you have the “1:64” geared version, it’s actually geared 8910:567424. The upshot? Instead of 2,048 steps per turn, you need 2,037.8864. Get this wrong and you’re losing 14 minutes per day with a 12-hour wheel.

So between just driving the motors, and the low torque and the non-integral gearing, there’s more to learn here than you’d think. You can add a real-time-clock circuit if you want it precise. With all this room to expand, you can get it built and running in a weekend for a few bucks. And that makes it the perfect “hello world”.

Filed under: clock hacks

Hackaday Prize Entry: Cheap, Open LiDAR

[adam] is a caver, meaning that he likes to explore caves and map their inner structure. This is still commonly done using traditional tools, such as notebooks (the paper ones), tape measure, compasses, and inclinometers. [adam] wanted to upgrade his equipment, but found that industrial LiDAR 3D scanners are quite expensive. His Hackaday Prize entry, the Open LIDAR, is an affordable alternative to the expensive industrial 3D scanning solutions out there.

The 3D scan of a small cave near Louisville from [caver.adam’s] Sketchfab repository
LiDAR — Light Detection And Ranging —  is the technology that senses the distance between a sensor and an object by reflectively measuring the time of flight of a light beam between the two. By acquiring a two-dimensional array of multiple distance readings, this can be used for 3D scanning. Looking at how the industrial LiDAR scanners capture the environment using fast spinning mirrors, [adam] realized that he could basically achieve the same by using a cheap laser range finder strapped to a pan and tilt gimbal.

The gimbal he designed for this task uses stepper motors to aim an SF30-B laser rangefinder. An Arduino controls the movement and lets the eye of the sensor scan an object or an entire environment. By sampling the distance readings returned by the sensor, a point cloud is created which then can be converted into a 3D model. [adam] plans to drive the stepper motors in microstepping mode to increase the resolution of his scanner. We’re looking forwards to see the first renderings of 3D cave maps captured with the Open LIDAR.

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Filed under: The Hackaday Prize

Circuit Bender Artist bends Fresnel Lens for Art

Give some mundane, old gear to an artist with a liking for technology, and he can turn it into a mesmerizing piece of art. [dmitry] created “red, an optic-sound electronic object” which uses simple light sources and optical elements to create an audio-visual performance installation. The project was the result of his collaboration with the Prometheus Special Design Bureau in Kazan, Russia. The inspiration for this project was Crystall, a reconstruction of an earlier project dating back to 1966. The idea behind “red” was to recreate the ideas and concepts from the 60’s ~ 80’s using modern solutions and materials.

The main part of the art installation consists of a ruby red crystal glass and a large piece of flexible Fresnel lens, positioned in front of a bright LED light source. The light source, the crystal and the Fresnel lens all move linearly, constantly changing the optical properties of the system. A pair of servos flexes and distorts the Fresnel lens while another one flips the crystal glass. A lot of recycled materials were used for the actuators – CD-ROM drive, an old scanner mechanism and old electric motors. Its got a Raspberry-Pi running Pure Data and Python scripts, with an Arduino connected to the sensors and actuators. The sensors define the position of various mechanical elements in relation to the range of their movement. There’s a couple of big speakers, which means there’s a beefy amplifier thrown in too. The sounds are correlated to the movement of the various elements, the intensity of the light and probably the color. There’s two mechanical paddle levers hanging in there, if you folks want to hazard some guesses on what they do.

Check out some of [dmitry]’s earlier works which we featured. Here’s him Spinning a Pyrite Record for Art, and making Art from Brainwaves, Antifreeze, and Ferrofluid.

Filed under: hardware, musical hacks

Precision CNC Drawing with EtchABot

Turning the classic toy Etch-A-Sketch into a CNC drawing tablet intrigues a large number of hackers. This version by [GeekMom] certainly takes the award for precision and utility. Once you build something like this, you can hardly stop writing firmware for it; [GeekMom] produced an entire Arduino library of code to allow joystick doodling, drawing web images, and a self-erasing spirograph mode. The topper is the version that runs as a clock!

The major hassle with making a CNC version of this toy is the slop in the drawing mechanism. There is a large amount of backlash when you reverse the drawing direction. If that isn’t bad enough, the backlash is different in the vertical or horizontal directions. Part of [GeekMom’s] presentation is on how to measure and correct for this backlash.

The EtchABot uses three small stepper motors. Two drive the drawing controls and the third flips the device forward to erase the previous drawing. The motors are each controlled by a ULN2003 stepper motor drivers. An Arduino Uno provides the intelligence. Optional components are a DS3231 Real Time Clock and a dual axis X-Y joystick for the clock and doodling capability. Laser cut wood creates a base for holding the Etch-A-Sketch and the electronics.

The write up and details for this project are impressive. Be sure to check out the other entries in [GeekMom’s] blog. Watch the complete spirograph video after the break.

Filed under: Arduino Hacks, toy hacks

3D Print Your Own Stepper Motor

Learn how one Maker created his own stepper motor using a 3D printer, an Arduino, and a few materials picked up from the hardware store.

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New Project: Build a Two-Octave Laser Harp

I find laser harps fascinating. The first time I saw one was when I stumbled across a video of a guy using using lasers to play the theme song to Tetris. I thought it was the coolest thing ever, but I couldn’t justify the cost of buying one. Instead, I decided […]

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