Still More Software Defined Radio Fun On The Mac

October 12, 2012 by 9 Comments

Even though the world of software defined radio started out as a Linux-only endeavor, several recent software releases have put the ball fully into the court of OS X users. [hpux735]’s new Cocoa Radio release provides a (nearly) fully functional software defined radio for anyone with a USB TV tuner and a mac.

Earlier this week, we saw (and tested)  [Elias]‘ port of gqrx and were reasonably impressed. [hpux735]’s app does the same job and also provides the source so you can compile it yourself.

Previously, [hpux735] ported the osmocom driver for these RTL2832U-based USB TV tuner dongles to the Mac and wrote a small Cocoa driver. The new Cocoa Radio software uses this driver and adds all the features you’d expect from a software radio package; in the title pic for this post, you can see a top 40 radio station near my house and their insipid hatred of dynamic range.

[hpux735] posted a few videos of his development process. You can check those out after the break.

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LED Matrix Pendants

October 12, 2012 by 35 Comments

If you want to mess around with some microcontrollers but don’t really have a purpose in mind this project is perfect for you. It’s cheap, easy to assemble, and there’s blinking LEDs! [TigerUp] shows us how he  put together some LED matrix pendants using just five components.

He calls the project Tiny Matrix, which is fitting as the pendant outline is barely 0.5″ by 0.7″. On the back an ATtiny2313 chip has been soldered directly to the legs of the LED display. They just happen to line up with I/O pins on the chip which makes for super simple soldering. Power comes from a coin-cell which is connected to the pendant by a red and black wire which make up the necklace for the device. The last two components not yet mentioned are a momentary push switch for changing modes, and a pull-up resistor on the reset pin. The bill of materials rings in at $4 and his firmware offers up nine different modes as you can see in the clip after the break.

[TigerUp] was inspired by this 8×8 matrix project.

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Stellaris Launchpad Library To Drive The TM1638 UI Board

October 12, 2012 by 3 Comments

For those that grabbed one of these TM1638 UI boards you can now easily use it with your Stellaris Launchpad. [Dan O] took it upon himself to publish an ARM library for the UI board.

There’s not a lot of new stuff to talk about here. We’ve already seen this being driven by an FPGA. [Dan] also links to both an Arduino and an MSP430 library for the board. The one thing that is good to know is that the board seems to run fine from the 3.3V supplied by the Stellaris Launchpad.

The ARM chip has four different hardware SPI modules which could have been used to drive this display. But [Dan] opted to bit bang instead. This give him more flexibility, like easily changing the pin mapping and foregoing the need for external components. All it takes is direct connections from three I/O pins which are used for clock, data in, and data out. We’ve embedded the obligatory demo video after the break.

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Nook Simple Touch As A Glider Computer

October 12, 2012 by 13 Comments

Look at the beautiful screen on that Nook Simple Touch. It has a lot of advantages over other hardware when used as a glider computer running the open source XCSoar software. The contrast of the display is excellent when compared to an LCD or AOMLED. That’s quite important as gliding through the wild blue yonder often includes intense sunlight. The display is also larger than many of the Android devices that have been used for this purpose. There are a few drawbacks though. One is that unlike other Android devices, this doesn’t have a GPS module built into it. But the price point makes up for the fact that you need to source an external module yourself.

This isn’t the first time we’ve seen the device used as a navigational display. This other hack put a simple touch on a sailboat for the same direct-sunlight-readability reason. For $100, and with the ability to root the system for use as an Android device, we expect to see this to keep popping up all over the place as a simple interface for a multitude of projects.

After the break you can see a video comparing the software running on a Nook display to one on a Dell Streak 5 LCD tablet.

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Malting Kiln Controller For Preparing Beer Brewing Grains

October 12, 2012 by 5 Comments

A quick primer is in order: when it comes to hobby brewing there’s two main types, extract brewing and all-grain brewing. The former uses a syrup that has been extracted from the grains at a factory while the latter adds the steps to do this yourself. But in both cases the brewing grains have already been malted. This is a careful process of soaking the grains and then kiln drying them. [Richard Oliver] built his own malt kiln controller to add the preliminary step to his home brewing ritual. Now the only thing he’s not doing himself is growing the grains (and perhaps culturing the yeast).

His original design used a food dehydrator for the drying step, but this didn’t work because the temperature wasn’t at the correct level. The new build uses the ceramic heating element from a 300W hot air gun. A blower directs air through the element and into the wooden box that serves as the kiln. An Arduino monitors the heated air to keep it right in the sweet spot. He’s included a graphing GUI for easy monitoring, which is shown in the video after the break.

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Building A Better PID Smoker Controller

October 11, 2012 by 20 Comments

[Matt] wanted to have more control over his meat smoker so he built this advanced PID smoker controller. It uses the solid state relay seen in the bottom-right of this image to switch the smoker’s heating element. But all of the other goodies that are included add several features not usually found in these builds.

This is a replacement for the commercial PID unit he used on the original build. That monitored the temperature in the smoker, using predictive algorithms to maintain just the right heat level. But this time around [Matt] is looking for extra feedback with a second sensor to monitor meat temperature. Using an Arduino with an SD shield he is able to data log the smoking sessions, and his custom code allows him to specify temperature profiles for resting the meat after it has hit the target temperature. It kind of reminds us of a reflow oven controller… but for food.

Programming Tetris By First Building A Logic Gate, Then A Computer, Then…

October 11, 2012 by 25 Comments

Hone your fundamental understanding of computer systems by completing this online course called NAND to Tetris. The idea is to develop each fundamental unit that goes into making computer programs a reality. This starts with logic gates, which are put together into modules that eventually become a functioning computer. From there you need an operating system,  a compiler, and eventually you’ll be playing a game of Tetris which you programmed yourself.

It’s certainly not an easy journey, but if you have a computer at your disposal you should be able to make it all the way through the course. There’s a software suite which includes a hardware simulator so that the computer you’re building can be assembled using HDL instead physical components.

The concept is discussed in this TED talk given by [Shimon Schocken]. It is also embedded after the break and in addition to the NAND to Tetris project he shows off some self learning software on the iPad. To us it seems very much like the learning software [Neal Stephenson] envisions in the Young Lady’s Illustrated Primer from his Diamond Age novel.

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