A Laminar Flow Nozzle

October 5, 2013 by Mathieu Stephan 10 Comments

A few years ago Hackaday featured a laminar project which recently inspired [Kurt] to create his own. His goal is to create a computer controlled night time light show synchronized with music.

The laminar nozzle shown in the picture above is built with 800 drinking straws all placed in parallel inside a 4″ PVC pipe. The water input is a 3/4″ garden hose adapter, perpendicular to the flow of the output nozzle. The built therefore consists of cleaning sponges placed near the water inlet, followed by the straws and an inch gap to the exit nozzle. To get a nice flow, the edge of the exit nozzle must be as sharp as possible. [Kurt] purchased a brass pipe end cap, drilled a hole in it and sanded it to create a sharp inner edge. For the lights, he used 2 high power LEDs mounted with 3mm fiber optic cables, driven at around 5 Watts.

The link to the article that inspired Kurt can be found here.

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Making A 9GHz Doppler Radar

October 3, 2013 by Mathieu Stephan 29 Comments

[Kalle] is currently building an FMCW radar, but as he doesn’t have all the parts finished he decided to build a 9GHZ doppler radar in the mean time. The H-plane horn antennas were made from brass sheet and soldered together. [Kalle] checked the matching between the emitter and the antenna by inserting a directional coupler between the two and measuring the intensity of the reflected signal (approximated return loss). At 9Ghz, the Doppler shift for a 1 meter per second speed is about 30Hz so he connected the radar’s output signal to his soundcard.

A quick explanation of the Doppler effect that a radar uses: if you send an RF signal at a given frequency to a moving target, the reflected signal’s frequency will be shifted. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession. Hackaday featured plenty of projects using this effect: a small doppler motion sensor, gesture control using doppler shift, hacking an old radar gun

The Intel-powered Arduino

October 3, 2013 by Brian Benchoff 149 Comments

Dev boards based on microcontrollers and ARM System on Chips are everywhere, but finding a small pocketable computer based on an Intel processor has been difficult to find. [Massimo] of Arduino just unveiled a new Intel architecture Arduino-compatible board at the Rome Maker Faire. It’s called the Galileo, and it has everything you’d expect from a juiced-up Arduino running x86.

The main chip is an Intel Quark SoC running at 400MHz with 256 MB of DRAM. On board is a Mini-PCIe slot, 100Mb Ethernet port, Micro SD slot, RS-232, and USB host and client ports. Here’s the datasheet for the Galileo with all the applicable information.

The Galileo can be programmed with the standard Arduino IDE, but from the getting started guide, it looks like this board is running Yocto, a stripped down Linux for embedded environments.

Realistically, what we have here is a board with about the same processing power as a Raspberry Pi, but with Arduino compatibility, and a Mini PCIe port for some really fun stuff. It will be interesting to see what can be made with this board, but if you have any ideas on what to do with a Galileo before it’s released in two months, drop a note in the comments.

PocketQubes: Even Smaller Than A CubeSat

October 2, 2013 by Brian Benchoff 24 Comments

Qube

Over one hundred CubeSats have been launched by hundreds of organizations and universities from around the globe. These have proven very useful in technology demonstration, Earth imaging, and other applications. There is, however, one large downside to the CubeSat platform. Even though it is designed to hitch a ride on launches of larger satellites, they’re still very expensive to develop and launch – somewhere between $60,000 and $125,000.

PocketQubes are a new design of satellite that bring the cost of personal satellites down to what Universities and amateur radio enthusiasts can actually afford. Instead of spending $125k on a 10cm cube CubeSat, the PocketQube, a 5cm cube, can be launched to a 700 km orbit for about $20,000.

Already, four PocketQubes are scheduled for launch in November to a 700km solar synchronous orbit, including $50SAT, a small radio transceiver put together by some ham guys, and The WREN a very impressive PocketQube with 3-axis reaction wheels and plasma thrusters.

Right now, the PocketQube kickstarter is only for aluminum structures that will become the skeleton of a small, 5cm cube satellite. There’s also the PocketQube Shop that provides a little more background on the project.

An Atmega328-based Radioteletype XY Scope Display

September 30, 2013 by Mathieu Stephan 5 Comments

[Jack] tipped us about a Crossed Bananas Display (CBD) he just designed. A CBD is a tuning aid for frequency-shift keyed (FSK) modes and is basically an oscilloscope in X-Y mode. At one time, radioteletype operators used binary FSK to transmit text over radio waves. In this scheme, the “1” is called the mark frequency and the “0” is called the space frequency. If both frequencies were perfectly tuned (correct phase) the resulting display would look like the one shown above, explaining the origin of the “crossed banana” name.

The build is based on an ATmega328 and a 1.8″ ST7735R display which has a 128×160 resolution. The MC33204PG operational amplifier is used in conjunction with a potentiometer to scale the input in the microcontroller ADC’s range. Another potentiometer sets the refresh rate of the graph. The whole project is enclosed in a painted cast-aluminium bud box and all the sources for this project can be found here.

Announcing Adafruit’s Bluefruit

September 24, 2013 by Brian Benchoff 16 Comments

adafruit_2098

You always meet the most interesting people wandering around Maker Faire, but by far the most interesting was Hackaday’s founder, [Phil Torrone] and bubblegum-haired compatriot [Limor] from Adafruit. They were out in full force checking out the sights and gave us the scoop on a new piece of hardware they’re releasing called Bluefruit.

Bluefruit is a very tiny and very cheap Bluetooth module breakout board that allows anyone to take 12 digital inputs and turn them into a Bluetooth HID device. If you’re planning a portable battery-powered arcade controller, just plug in a Bluefruit, set up your keypresses in your software, and rock out.

On board the Blufruit are an FTDI programming connector, 12 input pins, a few power pins, a custom FCC and CE certified CSR Bluetooth module, and that’s about it. If you’re looking for a simple GPIO to Bluetooth adapter without an overwrought Arduino setup, this is the best solution we’ve seen by far. Adafruit is also rocking their own custom firmware for the device, so this will be extremely hacker-friendly.

The price will be $20 and should be available in the Adafruit store in a bit. If you’re looking for an easy way to put a Bluetooth HID controller in your next project, this is the one.

Pictures of the Bluefruit and Adafruit crew below.

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Homebuilt 30kV High Voltage Power Supply

September 23, 2013 by Todd Harrison 13 Comments

If you have need for 30,000 volts to launch your ionocraft (lifter) or power other DIY projects then shuttle over to RimstarOrg’s YouTube channel and checkout [Steven Dufresne’s] homebuilt 30kV power supply. The construction details that [Steven] includes in his videos are always amazing, especially for visual learners. If you prefer text over video he was kind enough to share a schematic and full write up at rimstar.org.

The power supply can be configured for 1.2kV – 4.6kV or 4kV – 30kV at the output while requiring 0-24V DC at the input. In the video [Steven] tries two power supplies. His homemade DC bench power supply at 8V and 2.5A and also a laptop power supply rated at 20V 1.8A DC. A couple of common 2N3055 power transistors, proper wattage resistors, a flyback transformer and a high voltage tripler is about all you’ll need to scrounge up. The flyback transformer can be found in old CRT type televisions, and he does go into details on rewinding the primary for this build. The high voltage tripler [Steven] references might be a bit harder to source. He lists a few alternates for the tripler but even those are scarce: NTE 521, Siemens 76-1 N094, 1895-641-045. There are lots of voltage multiplier details in the wild, but keep in mind this tripler needs to operate up to 30kV.

Join us after the break to watch the video and for a little advice from Mr. Safety.

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