Posts | Comments

Planet Arduino

Archive for the ‘pendulum’ Category

Newton’s cradles consist of a series of suspended spherical masses, and are normally started by pulling one ball back. The outer balls then click back and forth for an interesting distraction. 

To make things even more interesting, “TecnoProfesor” made his own version using ping pong balls and RGB LEDs. As the outer balls sway, they light up in sequence, along with the inner three balls that stay largely in one place.

Power here isn’t provided by kinetic energy, but everything moves via a pair of servo motors. An Arduino Mega is used to control the light/motion simulator, while a button and potentiometer allow the user to change between two modes and variable swing frequency.

If you’ve ever tried to tune a PID system, you have probably encountered equal parts overwhelming math and black magic folk wisdom. Or maybe you just let the autotune take over. If you really want to get some good intuition for motion control algorithms, PID included, nothing beats a little hands-on experimentation.

To get you started, [Clovis] wrote in with his budget propeller-based PID demo platform (Portuguese, translated shockingly well here).

The basic setup is a potentiometer glued to a barbecue skewer with a mini-quadcopter motor and rotor on the end of it. A microcontroller reads the voltage and PWMs the propeller through a MOSFET. The goal is to have the pendulum hover stably in midair, controlled by whatever algorithms you can dream up on the controller. [Clovis]’ video demonstrates on-off and PID control of the fan. Adding a few more potentiometers (one for P, I, and D?) would make hands-on tweaking even more interactive.

In all, it’s a system that will only set you back a few bucks, but can teach you more than you’d learn in a month in college. Chances are good that you’re not going to have exactly the same brand of sardine can on hand that he did, but some improvisation is called for here.

If you don’t know why you’d like to master open-loop control algorithms, here’s one of the best advertisements that we’ve seen in a long time. But you don’t have to start out with hand-wound hundred-dollar motors, or precisely machined bits. As [Clovis] demonstrates, you can make do with a busted quadcopter and whatever you find in your kitchen.


Filed under: Arduino Hacks

Photo: Neil MendozaIt's just an egg, placed in a vulnerable position. "I thought it would be fun to pit a large metal machine against a small fragile object," says Mendoza.

Read more on MAKE

The post Try Not to Have a Heart Attack While Watching This Egg/Pendulum Dance appeared first on Make: DIY Projects, How-Tos, Electronics, Crafts and Ideas for Makers.

You have to admit [Dylan Rush’s] clock is a real swinger. Literally. You’ve seen the desk novelties where an arm with leds mounted on it sweeps out a message? [Dylan] did the same thing to make a clock but instead of drawing numbers, he actually draws an analog clock face. Y’know one of those round things with arms?

IMG_20150824_2156213_rewindBehind the clock is an Arduino driving a MAX7219 LED controller. Using the MAX7219 was a challenge because it expects a grid of LEDs while the clock needs a linear array. [Dylan] used a line of individual LEDs wired to match what the controller wanted. A rotary encoder tells the processor the position of the arm so the Arduino sketch can determine which LEDs should be lit to show the time and clock face.

What’s even more amazing is [Dylan] created this before clocks became infamous.

Swing over to the video after the break.


Filed under: Arduino Hacks, clock hacks, led hacks
Giu
04

Pendulum MIDI Controller Really Swings

arduino hacks, arduino nano, Maxuino, Midi, midi controller, musical hacks, pendulum Commenti disabilitati su Pendulum MIDI Controller Really Swings 

Once in a while, we see a project that makes us want to stop whatever we’re doing and build our own version of it. This time, it’s Modulum, a pendulum-based MIDI controller. It’s exactly what it sounds like. The swinging pendulum acts as a low-frequency oscillator. In the demo video configuration, you can hear it add a watery, dreamlike quality, sort of like a lap steel guitar on LSD.

The pendulum’s motion is detected by four pieces of stretchy, conductive cord. These are wired to an Arduino Nano in a voltage divider fashion. [Evan and Kirk] used the Maxuino library to determine x and y mapping of possible pendular positions as well as perform the necessary MIDI processing. Get your groove on after the break, and check out some of the many other fantastic MIDI controllers we’ve had the pleasure of covering.


Filed under: Arduino Hacks, musical hacks


  • Newsletter

    Sign up for the PlanetArduino Newsletter, which delivers the most popular articles via e-mail to your inbox every week. Just fill in the information below and submit.

  • Like Us on Facebook