Measuring Magnetic Fields With A Robotic Arm

March 30, 2014 by Nick Conn 13 Comments

MagneticArm

Learning how magnets and magnetic fields work is one thing, but actually being able to measure and see a magnetic field is another thing entirely! [Stanley’s] latest project uses a magnetometer attached to a robotic arm with 3 degrees of freedom to measure magnetic fields.

Using servos and aluminium mounting hardware purchased from eBay, [Stanley] build a simple robot arm. He then hooked an HMC5883L magnetometer to the robotic arm. [Stanley] used an Atmega32u4 and the LUFA USB library to interface with this sensor since it has a high data rate. For those of you unfamiliar with LUFA, it is a Lightweight USB Framework for AVRs (formerly known as MyUSB). The results were plotted in MATLAB (Octave is free MATLAB alternative), a very powerful mathematical based scripting language. The plots almost perfectly match the field patterns learned in introductory classes on magnetism. Be sure to watching the robot arm take the measurements in the video after the break, it is very cool!

[Stanley] has graciously provided both the AVR code and the MATLAB script for his project at the end of his write-up. It would be very cool to see what other sensors could be used in this fashion! What other natural phenomena would be interesting to map in three dimensions?

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A Mini Op-Amp Based Line Following Robot

March 28, 2014 by Nick Conn 10 Comments

LineRobot

There’s no denying it. Super small robots are just cool. [Pinomelean] has posted an Instructable on how to create a mini line following robot using only analog circuitry. This would make a great demo project to show your friends and family what you’ve been up to.

Analog circuitry can be used instead of a microcontroller for many different applications, and this is one of them. The circuit consists of two op-amps that amplify the output of two phototransistors, which control each motor. This circuit is super simple yet very effective. The mechanical system is also quite cool and well thought out. To keep things simple, the motors drive the wheel treads, rather than directly through an axle. After the build was completed, the device needed to be calibrated by turning potentiometers that control the gain of each op-amp. Once everything is balanced, the robot runs great! See it in action after the break.

While not the smallest line follower we have seen, this robot is quite easy to reproduce. What little robots have you build lately? Send us a tip and let us know!

[via Embedded Lab]

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Building A Network Controllable RGB LED Lamp From An Old Scanner

March 26, 2014 by Nick Conn 13 Comments

EthernetLamp

Being able to use one of your old projects to make a new one better can be quite satisfying. [Steve] from Hackshed did just this: he integrated an Arduino based webserver into a new network controllable RGB lamp.

What makes this lamp unique is that the RGB LED bar comes from an old Epson scanner. Recycling leftover parts from old projects or derelict electronics is truly the hacker way. After determining the pinout and correct voltage to run the LEDs at, the fun began. With the LED bar working correctly, the next step was to integrate an Arduino based webserver. Using an SD card to host the website and an Ethernet Arduino shield, the LEDs become network controllable. Without missing a beat, [Steve] integrated a Javascript based color picker that supports multiple web browsers. This allows the interface to look quite professional. Be sure to watch the lamp in action after the break!

The overall result is an amazing color changing lamp that works perfectly. All that is left to do is create a case for it, or integrate it into an existing lamp. This is a great way to use an LED strip that would have otherwise gone to waste. If you can’t find a scanner with a color wand like this one, you can always start with an RGB strip.

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Learning Assembly With A Web Based Assembler

March 23, 2014 by Nick Conn 47 Comments

AssemblyOnline Very few people know assembly. [Luto] seeks to make learning assembly just a little bit easier with his “fully functional web-based assembler development environment, including a real assembler, emulator and debugger.”

These days, you can be a microcontroller expert without knowing a thing about assembly. While you don’t NEED to know assembly, it actually can help you understand quite a bit about embedded programming and how your C code actually works. Writing a small part of your code in assembly can reduce code size and speed things up quite a bit. It also can result in some very cool projects, such as using Java to program microcontrollers.

With high quality example code, it is very easy to get started learning assembly. The emulator consists of a microcontroller with 32 registers, hooked up to three LEDs, two buttons, and a potentiometer. This is way better than painfully learning assembly on real hardware. Be sure to check out the online demo! Being able to step through each line of code and clearly see the result help make assembly easier to use and understand. It would be great to see this kind of tool widely adopted in engineering programs.

Have you used assembly in any of your projects? Let us know how it went and why you choose to use assembly

Modular Arduino Based Infrared Thermometer

March 20, 2014 by Nick Conn 2 Comments

IRTemperature

[Brian] started out with a clear and concise goal, “allow a regular human to associate an audible tone with a temperature from an infrared contactless thermometer.” With his latest project, the ESPeri.IRBud, he has achieved this goal.

One of our favorite parts of [Brian’s] post is his BOM. Being able to easily see that the IR temperature sensor costs $26 at DigiKey is unbelievably helpful to readers. This specific sensor was chosen because others have successfully interfaced it with the Arduino. Not having to reinvent the wheel is good thing! For the build, [Brian] decided to hook up the IR temperature sensor to a re-purposed flexible iPhone headset wire. Having used headphone sockets to connect to the sensor and speakers, the actual device is quite modular. Hearing this thing in action is quite cool, it almost sounds like old-school GameBoy music! Check it out after the break.

Have you used an IR temperature sensor in one of your projects? Let us know.

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Etching Designs Into Denim With A Laser Cutter

March 19, 2014 by Nick Conn 49 Comments

JeansEtchLaser

Finding new uses for your tools and equipment can be very exciting. [Foamy] wrote in to tell us about a blog post by [qbotics] that demonstrates etching designs into denim with a laser cutter. What a cool unexpected use for a laser cutter!

According to the Epilog laser cutter’s website, “we have engraved everything from denim to acrylic with fantastic results”. This inspired the author of “Science with denim” to try engraving jeans. After some experimentation, [qbotics] found that setting the 75W laser cutter to 15% power at 100% speed worked best. The results are quite impressive; the engraved pattern looks like naturally faded jeans. Amazing.

In the past, we have seen lasers engrave everything from calculators to wood. We would be curious to see if some of the DIY laser cutters could engrave denim as well. Give it a try and tell us about it!

A 3-Axis Paper Cutting Mini Laser

March 16, 2014 by Nick Conn 29 Comments

LaserCutter

Laser are awesome, and so are projects that use lasers. A recent Instructable by [kokpat] gives an overview of how to create a fully functional laser paper cutter using CDROM stepper motors and an Arduino.

What is special about this build, is that it showcases how easy it can be to build a 3-axis mechanical system used for laser cutters, CNC machines, and 3D printers. Using a stepper stage that consist of a motor screw with a nut slider based carriage, the mechanical system can be put together quite easily and cost effectively. Luckily, from an electronics and software perspective, everything is quite standardized with the proliferation of the RepRap and similar machines. Simply pick any three stepper drivers, find the most pertinent firmware, and voilà! You’re done! Well, almost. Don’t forget a 100mW violet laser!

We have seen a ton of really cool laser cutters before, but this has to be one of the cheapest. See the laser cutter in action after the break.

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