Year: 2010

Matrix Clock Is A Breadboarding Win

September 22, 2010 by 23 Comments

Normally when we feature a clock made with a 32×8 LED matrix we’d load up an image of the display for the banner photo. But this time around we were so impressed by [JB’s] breadboard work we had to use this image. We see an ATmega168, three buttons, three LEDs, a piezo buzzer, 32.768 kHz crystal, smoothing capacitor, and a few resistors; everything he needed to keep time and display it on the matrix module. If this is just going to sit on your bookshelf for a while it’s a great alternative to point-to-point soldering on a protoboard. Nice work fitting it all on there [JB].

Audio Ads In Newspapers?

September 22, 2010 by 33 Comments

Oh no, lets hope this little gimmick doesn’t catch on. Volkswagen has put out an advertisement in an Indian newspaper that plays an audio file when you unfold the paper. This appears to work much like those greeting cards that play a song when you open them. There’s a sensor that detects the newspaper opening, probably just a piece of plastic or paper that slides out from between two contacts. This allows power to the circuit and the audio file is played.  Can you imagine how obnoxious this could be? Especially if your newspaper was riddled with these and those E-paper screens.  Then again, that speaker looks like massive overkill for this kind of thing and might be a decent piece electronics to keep in the reuse bin. You can see a video of the newspaper after the break.

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Small And Simple FM Radio

September 21, 2010 by 23 Comments

[gpsKlaus] built this little FM radio (translated) based on the AR1010 IC. That chip is controlled via I2C by an ATtiny45 microcontroller. His tuning implementation relies on presetting 16 stations in the firmware and selecting them with the white potentiometer.

The FM chip came on a breakout board from SparkFun. Not bad at around $15 as it includes the crystal, some caps and a few resistors, and you don’t have to try and solder to the fine pitched pads on that minuscule package. We’re a little unsure of the features included in the part as the datasheet is lacking in detail and the reference datasheet that SparkFun includes in the description is obviously for a much more full-featured chip. Still, this would be a fun thing to play around with if you’ve grown tired of blinking LEDs.

If you don’t want to let an integrated circuit do all the heavy lifting try this post for a guide on building your own radio tuner.

Discussing Pulse-Width Modulation

September 21, 2010 by 53 Comments

[Michael Kleinigger] posted a lengthy discussion on Pulse-Width Modulation that goes beyond the traditional beginner tutorial. He starts a bit of background info on PWM and a tip about using a camera to judge frequency and duty cycle of LEDs. From there it’s down the rabbit hole with some testing of power-loss versus frequency.

When you change from frequencies of 50 Hz to 1 MHz how does the parasitic power loss from switching affect the overall efficiency of the circuit? It turns out there’s a rather large amount of loss at the highest level, around 1.5 mW. The greatest balance of low power loss and elimination of flicker seems to be right in the 300-500 Hz range.

Another Approach To Power Meter Data Harvesting

September 21, 2010 by 17 Comments

[Dodgy] wrote in to talk about his power meter data harvesting programs. This uses the same hardware by CurrentCost as the hack we looked at over the weekend but [Dodgy’s] implementation is different. It’s separated into two parts, the first is a webserver written in C that harvests the data and makes it available at an address on the network, the second is written in Perl to format and upload data to Google PowerMeter.

The C program serves data on a configurable port, defaulting to 3090. All of the data can be accessed in one line of code by loading http://127.0.0.1:3090, or individually with subdirectories like /watts, /time, or /tempr. From there you can do what you want with the data. The second part of [Dodgy’s] suite is a Perl script that polls the C server and sends the data to your Google account.

One thing that interests us is his comment that you should be able to compile the server side C code for an embedded device. It would be a nice energy savings to be able to upload data regularly without a PC running constantly.

Hackerspace Competition: Looks Promising

September 21, 2010 by 18 Comments

This is what happens when [Mitch Altman] comes together with hackerspaces nationwide to have a contest. In short, 5 hackerspaces  will “take on the machine” and come up with 5 original ideas for existing devices. There are a few more rules, but you can catch them in the video in the link above. There is hinting at a slot machine that mixes drinks, a bike that makes ice cream, and more. What do you guys think is in store?

This is also a great opportunity to mention the hackerspaces wiki, find a community (or start one!) near you today and maybe [Mitch] will call on your hackerspace next competition. For now, we’ll keep you up to date with each hackerspace’s project and progress.

[Thanks Deven]

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Machined Steadicam, Steadier Than The Rest

September 21, 2010 by 11 Comments

No, the picture above is not a store made steadicam. Rather, a CNC machined one by [Matt]. Interestingly, unlike most steadicams we’ve seen before the gimbal is not the main focus of the design though an aluminum machined gimbal would make us drool. The central idea is allowing for X and Y axis adjustment to get oddly weighted bulky camera’s exact center of gravity. [Matt’s] steadicam is also designed to handle more weight than commercial versions, and (if you already have a CNC) to be much cheaper. There’s no video, but from the skill of craftsmanship we can safely assume it’s as good and level as some of the best.