Arduino Powered 2.4 GHz Spectrum Analyzer

July 25, 2011 by Jesse Congdon 8 Comments

[Fred] dropped a note in our tip line to let us know about arduino forum user [bilbo]’s latest project: A 3-in-one spectrum analyzer, oscilloscope, volt-meter combo. The build consists of an Arduino, radio board and Nokia 5110 LCD breakout board. The (thin) video after the jump shows the rig in action. Though soldered to a full sized perf-board we can see later, smaller, battery powered versions prove useful in rooting out wayward bluetooth signals, or just finding that lost microwave oven. Although [bilbo] uses the same radio board as similar builds his creation boasts several different display modes, as well as doubling as a volt meter and miniature-oscilloscope. There is no shortage of previous spectrum analyzer builds, but this one is the first one we have seen running on an Arduino.

Thanks for the tip [Fred]! If you feel like wedging some frequency scanning capabilities into your next project don’t forget to check out [bilbo]’s forum posts for source code!

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Resistor Substitution Box

July 22, 2011 by Brian Benchoff 16 Comments

[Vincent] on the EEVblog forums had an idea for an inexpensive resistor substitution decade box.

The build uses cheap decimal thumbwheel switches he bought on eBay. Each switch is wired up with resistors for each digit, and each switch is wired up in series. The result is a small, easy to read resistor box with a range of 1 Ω to 10 MΩ.

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DIY Robot Remote Control

July 18, 2011 by Brian Benchoff 5 Comments

[Patrick] wanted a remote control to control some of the robots he’s built. He also wanted to get some data back from his robots, so an inexpensive off-the-shelf solution wouldn’t be up to the task. Like all good geeks, [Patrick] decided to build what he needed.

For analog control, [Patrick] decided to use a Wiimote nunchuck. This turned out to be a very good choice – the nunchuck has a 2-axis joystick and 3-axis accelerometer in one small, easy to interface package . The wireless radio is taken care of with an XBee module. For the microcontroller, custom “lcd backpack” was created that provides an I2C port for the nunchuck, inputs for the buttons and the single pot, and 2 serial ports for the FTDI and XBee.

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Cheap And Easy PCB Agitator From An Old CD-ROM

July 17, 2011 by Mike Nathan 32 Comments

cdrom_pcb_agitator

Instructables user [mzsolt] enjoyed making his own PCBs, but he wanted to speed up the etching process just a bit. While some people put together elaborate bubble tanks and agitators, he wanted to keep his simple and more importantly, cheap.

He looked around the house and discovered an ancient CD-ROM drive that was collecting dust, which he figured would make a great agitator for smaller projects. He picked up a decade counter and a handful of other cheap components, then got busy pulling the drive apart. He connected the motor and the drive’s limit switches to the decade counter, which controls the entire setup.

When powered on, the drive ejects, taking his container full of etchant with it. When the drive hits the outer limit switch, the decade counter reverses the motor until it hits the inner switch, reversing the motor once again.

As you can see in the video below, it works reasonably well. He suggests using a variable power supply to regulate the motor’s speed, but a variable pot would probably work just as well. Obviously the agitator is best suited for smaller projects, but since it was so cheap to put together, you won’t hear us complaining.

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Accounting For Material Loss When Laser Cutting

July 12, 2011 by Mike Szczys 22 Comments

When you cut something out, you lose a bit of material in the process. Think of a table saw and the sawdust it produces, that’s the waste material lost in an area the width of the blade. It’s really easy to measure that, just measure the blade. But [James] started wondering about a good way to measure material loss from a laser cutter.

Why does it matter? If you’ve designed pieces that should fit together with each other, loss of material can lead to joints that aren’t tight. [James] figured out that the loss could be measured by making several cuts within a rectangular frame. You can see his test pieces above, with ten strips cut out of each frame. After the laser is done doing it’s work just slide all the pieces together and measure the opening created at one end. It helps to have an enhanced caliper to make the measurement easy to read. Now divide that distance by the number of laser passes and account for that dimension next time you design parts for the cutter.

DIY Table Saw Cuts Through Anything, Leaves No Room For Mistakes

July 7, 2011 by Mike Nathan 62 Comments

Students in the BASTLI lab at the Swiss Federal Institute of Technology Zurich had been stuck using underpowered and unreliable saws for quite some time. The saws often got stuck while cutting through PCBs and were generally a drag to use. When group member [Mario Mauerer] came across a big and powerful brushless motor in his basement, he decided it was time to upgrade the lab’s cutting tools.

Along with fellow student [Lukas Schrittwieser] he built a test rig to see how powerful the motor really was, and satisfied with the results, the pair set off to build their own table saw. The enclosure was wrapped up pretty quickly, leaving the pair to source a power supply. Rather than purchase one, they built a 700w monster switching PSU to power their saw.

As you can see in the video below the saw chews through most things with the greatest of ease, but the students added a “boost button” to the saw just in case they need to run it at full tilt.

While we can’t exactly overlook the lack of finger and eye protection in their demonstration, it does look like a great little tool to have around.

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CEE Is A Swiss Army Knife For Analog Electronics

July 4, 2011 by Brian Benchoff 28 Comments

The team at nonolith labs announced their CEE, a device for billed as, “an analog buspirate” that is meant to control, experiment, and explore the world of analog electronics. Nonolith labs started a kickstarter campaign for the CEE.

The CEE is capable of sub-millivolt and milliamp sampling at 44.1k samples/second, and sourcing 2 channels of 5V @ 2A with a little bit of soldering. This allows for precise control of motors and sensors with the web-based UI. We’re thinking this would be a great way to teach high schoolers the art of electronics, and would be great combined with a few lectures from Paul Horowitz.

The CEE ties into nonolith labs Pixelpulse, a pretty handy tool for visualizing analog and digital signals. You can check out a demo of Pixelpulse simulating a charging capacitor here.

We’re hoping this focus on education on analog electronics catches on – you can learn a lot more by building a 555-based mini Segway than you can slapping a microcontroller in every project. This would go under the same theory as, “any idiot can count to one.”

Check out the video of the CEE on the kickstarter campaign page.