Building A Bandwidth Meter

Here’s an analog bandwidth meter made to look like an old pressure gauge. It’s actually new, but the paper showing the graduated scale was stained in a bath of black tea, then dried in an oven to give it an aged appearance. We think it’s quite effective.

The dial itself is a volt meter driven by an Arduino in much the same way as the multimeter clock. Bandwidth data is pulled from a Linux router, filtered down to the target data using ‘grep’, and sent over the serial connection by a Perl script. Since the meter itself is just waiting for serial data, alterations to the router’s scripting make it easy to represent a count of unread emails, tweets, or whatever data your code can scrape.

[Thanks Ben]

Arduino + Java + Joystick

Interfacing your own hardware with a Java app couldn’t be easier than this example. [Pn] created this proof-of-concept using an Arduino, an analog joystick from a gaming controller, and a few lines of Java code. The Arduino reads an ADC value from the joystick’s x-axis and transmits it over the serial connection ten times a second. The Java program triggers on every serial event, parsing the data based on the @ symbol that the Arduino sends as a start and end condition.

We like this kind of example because there’s nothing extra involved. It lets you take the concept and run with it in any project imaginable. Be it a more complicated Joystick, or simple sensors that you’d like to interface with.

Monotron Openly Monophonic

Famous synth manufacturer Korg has released the schematics (get them here if you don’t like to fill out forms) for their wee little Monotron for all to see and use! This is great news for anyone looking to build up a synth from scratch or to circuit bend their existing monotron. The filter circuits alone would be fun to add to an existing electronics setup.

Granted there are already many examples of monotron mods out there, but that shouldn’t stop you from experimenting with your own variations. Now with the schematics you can make fundamental changes to the architecture of the synth all from the comfort of your own CAD software. Want more oscillators? Distortion? It’s all out there for you to explore. We’re very interested to see how far people will run with this. And big ups to Korg for recognizing the value of hacking!

[via Retrothing]

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Analog Stylophone

[Doug Jackson] just finished building an analog Stylophone. We’ve seen this instrument a few times before, most recently with an Arduino-based controller, but this one makes use of 555-timer, resistors, and potentiometers to generate the waveform for each note. If you’ve got the copper-clad and the means to etch the board everything else should be pretty easy to come by. We did note that since this is a single-sided board you’ll be soldering on the same side as the components, which can get a bit hairy but manageable. We just wish that [Doug] has posted a demonstration video so we could hear what this sounds like. But it can’t be too much different from that electronic vuvuzela that used a 555 timer as well.

Line Following Tank Without A Microcontroller

This line following tank uses analog circuitry to sense where a dark line is and adjust its course. Despite the opening paragraph on the schematic page (which looks to be leftover from a past project writeup) this circuit relies on a set of transistors for motor control. [Chris] does a great job of explaining the setup in detail; it boils down to a phototransistor detecting reflected light and flipping which motor is running based on what is detected. A couple of potentiometers are included to tune up the accuracy of the circuit. There’s a short clip of the treaded-terror making a loop around the track after the break.

This is another great way to try your hand at analog circuitry. Once you’ve built the body (tank or otherwise) and line tracking circuit it can be repurposed by swapping out the brains for your next project.

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Meter Clock Using The TI Launchpad

Here’s an analog meter clock using an MSP430G2211 microcontroller. [Doug Paradis] chose this processor because it is the lesser of the two that come with the TI Launchpad. The parts count is fairly low too; a clock crystal, two analog meters, a few buttons, and a voltage regulator.

He’s done a nice job putting this together. We challenge you to give this a try yourself and build on [Doug’s] features. We really liked the calibration subroutine in [Alan’s] multi meter clock. It would be fun to implement that functionality and store the calibration code in the MSP’s flash memory. You can use our ported garage door opener code if you need an example of how to store data in flash.

Beginner Concepts: Analog Circuits

We look at a lot of projects that have microcontrollers in them. That’s because microcontrollers do cool stuff, but there are still plenty of tricks you can pull off with analog circuits. [Osgeld’s] latest project explores this realm, controlling the discharge of capacitors through an LED. His setup uses just nine components and, if you’ve been collecting broken electronics from your friends and neighbors like a good hacker, you can scavenge all of these parts. Try it, you’ll like it!