Pokewithastick, An Arduino Programmable Web-logger/server

October 8, 2013 by Mathieu Stephan 7 Comments

[Stewart] tipped us about his very nice project: pokewithastick. It is an Arduino compatible board (hardware, not footprint) based on the ATMEGA1284P which can be programmed to collect and post data to internet logging sites such as Thingspeak or Xively.

As you can see in the picture above, it has a small 50x37mm footprint (roughly 2″x1.5″). The pokewithastick is composed of an Wiz820 Ethernet module, a micro-SD card slot, 2 serial ports, one battery backed Real Time Clock (RTC), one radio connector (for the usual nRF24L01 2.4GHz radio), one power & user LED and finally a reset button. There are two power rails on the board which can be split (5v + 3.3V) or combined (3.3v only) which may allow you to connect Arduino shields to it. You can program the board using the standard 6-pin header or via a serial programmer if an appropriate (Arduino) bootloader is installed.

The project is open hardware, has been designed using Kicad and all the files can be downloaded as a zip file.

Custom HTPC And Home Media Server

October 7, 2013 by Marsh 21 Comments

[Benoit Frigon]’s builds are a tribute to tidiness: both his HTPC and media server are elegant creations packed full of features. He has quite the knack for clean builds in this form factor; his PBX server was met with high praise earlier this summer.

For the HTPC, [Benoit] gutted and cleaned an old DVR case and modified it to house a Mini-ITX board. He added standoff mounts to support the motherboard, then sketched up a template for the IO shield as a guide for cutting the back panel. The front of the DVR case originally had a 4-digit 7-segment display and a few simple buttons. Though he kept the original button layout, [Benoit] chose to replace the segment displays with a 20×2 character LCD. The new display is controlled via a python script on the HTPC, which runs an OpenElec Linux distro with XBMC 12.0.

The HTPC’s hard drive bay is a bit lighter these days, because [Benoit] decided to migrate his media storage to a separate server. Inside the new home media server is yet another Mini-ITX motherboard with an embedded Atom N2800 that runs Ubuntu Server. Live television streams via a WinTV HVR-2550 TV tuner and TVHeadend software. The case originally suspended the tuner from the IO bracket on the back (and nowhere else), which left the rest of the card dangerously unsupported inside. [Benoit] solved the problem by building an additional aluminum bracket that firmly holds both the PCIe riser and the tuner. Check out both builds’ pages for downloadable templates, software details and bill of materials.

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.

Continue reading “A Laminar Flow Nozzle” →

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.