Tag Archives: Instructable

Tracking cat eyes with Arduino and Kinect

A Maker by the name of jgbradley1 recently shared his innovative graduate project on Instructables that describes how a Kinect and an Arduino Uno (ATmega328) can be paired to create illustrated cat eyes that “track” an individual.

Aside from the Uno and Kinect, key project components include:

  • Creepy cat poster
  • 2x 1 1/2″ wooden balls
  • Paint
  • 2x standard servo TowerPro SG-5010 motors
  • 8xAA batteries (battery case optional)
  • IC breadboard
  • Hot glue gun

jgbradley1 kicks off the project by cutting out and painting eyeholes, mounting the eyeballs onto server motors, attaching the motors to the back of the poster and configuring the circuit.

“Since we need to power two servos at the same time, we cannot rely on power from an Arduino alone. An external power source is required for the motors. Each servo is rated to work at 4.8V – 6V,” the Maker explained.

“Therefore, a 12V power source (an 8 AA battery pack works well) for the motors should be fine. If the motors were controlled one at a time, you could easily run both off of the Arduino.”

In terms of programming, jgbradley1 uses a servo library on the Arduino side, with Processing (simple-openni library) chosen for the Kinect.

Interested in learning more about the building your own tracking cat eyes? Check out the project’s official page here.

Designing an Arduino-based coffee roaster

Brenn10 recently upcycled an ordinary air popcorn popper by transforming the device into a slick Arduino-based controllable coffee roaster.

“The extraction of the complex aromatic and flavor characteristics of a coffee bean is dictated by a roaster’s ability to control a variety of variables that act on a green coffee bean while it is roasting,” Brenn10 explained in an Instructables post.

“Not only must one understand certain audible and visual cues from the beans during the course of the roast, but the roasting apparatus must also react to changes to the fan speed and heater power in order to change the temperature inside of the roasting chamber.”

Concurrently, the roast logging software should display a graphical summary of the temperature in the chamber versus time – also known as the roasting profile.

Enter the upcycled controllable coffee roaster. As Brenn10 notes, a modified popcorn popper is capable of rivaling the functionality of a high-end programmable roaster – if properly equipped with internal temperature sensors, a reactive control system and an intuitive UI programmed to save multiple roasting profiles.

“The modified popcorn popper will [also] automatically control the temperature and total roast time based on industry roasting profiles,” Brenn10 continued.

“Component costs [should] remain under $360; [with] a taste comparison between beans roasted in a modified and unmodified roaster completed by an experienced coffee taster.”

Indeed, Brenn10’s upcylced roaster controls both the power to the heater coil and the speed of the universal AC/DC motor tasked with blowing air over the heating coil. More specifically, the air is directed into the roasting chamber where thermocouples relay temperature information to a microcontroller interfaced with a roast logging software known as Artisan.

“This roast logging software displays the temperature versus time inside of the roasting chamber, while also providing functionality to the roaster user to adjust the percentage of power going to the heater coil and the percentage of speed that the fan is spinning,” Brenn10 added.

Aside from an Atmel-based Arduino Uno (ATmega328 MCU) key project components include:

  • Crydom D2425-10 Solid State Relay
K-Type Thermocouple – Glass Braided
  • K-Type Thermocouple – Flexible Probe
  • TC4 Roasting Thermocouple Shield – (Kit or Pre-Built)
Zero Cross Detector
Terminal Block – 8 Total Connections
  • 12” jumper wires
  • Wooden Project Box
  • Antique Glass Chimney

Interested in learning more? You can check out the project’s official Instructables here for a detailed, step-by-step tutorial on how to transform a standard air popcorn popper into a controllable coffee roaster.

Arduino powers these solar-tracking blinds

Yesterday, Bits & Pieces took a closer look at an Instructable that described how to automate smart window blinds with an Arduino Fio. Today, we’re going to be covering a solar-tracking automatic motorized window blind project powered by an Atmel-based Arduino Uno (ATmega328 MCU).

“Sunlight can be broken into essentially two components: direct and diffuse. The direct component comes straight from the sun, whereas the diffuse component is created when a portion of direct sunlight scatters due to molecules in the atmosphere,” project creator Nickzibin explained in a recent Instructables post.

“This project aims to control shade position to always block direct sunlight when present and maximize the diffuse component entering the workspace.”

As such, the motor moves the shade position depending on the of the location of the sun and the amount of light hitting a specific (targeted area). One of the best parts of this Instructable? Makers don’t need to purchase a brand new roller shade to make it work.

Aside from the Atmel-powered Arduino board, key project specs include:

  • Adafruit motor shield
  • Headers
  • Digital luminosity sensor
Stepper motor with planetary gear box
  • Power supply (12V)
3D printed gear via shapeways.com
Elastic band
  • Parametric CAD file of ball-chain gear

Perhaps the most important part of Nickzibin’s retrofitted solar-tracking blinds project is the control strategy algorithm based on the Tzempelikos method, where the shade height is controlled based on the calculated position of the sun and corresponding brightness.

“Their algorithm was based on open loop procedures which moved shade height to the position where it just blocks direct sunlight from falling on the workplane. The code in this project adopted their open loop aspects and added closed loop control during certain conditions,” said Nickzibin.

“The position of the sun is known in terms of its solar altitude (α) and solar surface azimuth (γ). The solar altitude is the angle between the horizon and the sun. The solar surface azimuth is the angle between the outward normal of a surface (e.g., vertical window) and the sun.”

More specifically, Nickzibin’s code calculated α and γ based on latitude, longitude altitude and angle from south to outward normal of vertical surface (azimuth) – all based on the following variables:

  • The sun is on the window surface: α > 0° & |γ| < 90°
  • The sun is not on the window surface: α > 0° & γ > 90°
  • The sun is below the horizontal α < 0°

“Developing prototypes using Arduino specific to building technology has [significant] potential to substantially reduce energy use in buildings,” Nickzibin added.

“This project can be easily integrated with a lighting system. In the future, the system could also be integrated with an HVAC system in order to minimize cooling and heating loads.”

Interested in learning more? You can check out Nickzibin’s official project page here.

Arduino goes virtual with Autodesk

Autodesk and Circuits.io have launched a new tool that allows DIY Makers to more easily design and test projects powered by Atmel-based Arduino boards.

Aptly dubbed 123D Circuits, the utility boasts a virtual breadboard-based design which enables Makers to build and experiment with Arduino circuits just as they would in real life. Code can be edited in a browser, facilitating real-time and interactive simulation of the targeted circuit. Plus, Makers are now able to simultaneously work on the same (virtual) project with their friends, compiling and emulating  Arduino code inside a live, editable circuit.

Additional key features and capabilities include:

  • A powerful, yet easy-to-use component editor which makes it easy to add new components to the shared library.
  • Facilitates the creation of slick circuit boards with free text, b-splice silkscreen art and arbitrary board shapes.
  • Capable of embedding designs, including simulations, on a blog or in an Instructable.

Interested in learning more? You can check out the official Sandbox page here.