XOXO For The OCXO

July 3, 2014 by 7 Comments

HPocxo

[Kerry Wong] recently got himself a frequency counter. Not just any counter, a classic Hewlett-Packard 5350B Microwave Counter. This baby will go 10Hz all the way up to 20GHz with only one input shift. A true fan of Hackaday Prize judge [Dave Jones], [Kerry] didn’t turn it on, he took it apart. In the process, he gave us some great pictures of late 80’s vintage HP iron.

Everything seemed to be in relatively good working order, with the exception of the oven indicator, which never turned off. The 5350B had three time bases available: a Thermally Compensated Crystal Oscillator (TCXO),  an Oven Controlled Crystal Oscillator (OCXO), and a high stability OCXO. [Kerry’s] 5350B had option 001, the OCXO. Considering it was only a $750 USD upgrade to the 5350B’s $5500 USD base price, it’s not surprising that many 5350B’s in the wild have this option.

[Kerry] checked the wattage of his 5350B, and determined that it pulled about 27 watts at power up and stayed there. If the OCXO was working, wattage would have dropped after about 10 minutes when the oven came up to temperature. Time to tear open an oven!

Armed with a copy of the 5350B service manual from HP’s website, [Kerry] opened up his OCXO. The Darlington transistors used as heaters were fine. The control circuit was fine. The problem turned out to be a simple thermal fuse. The service manual recommended jumping out the fuse for testing. With the fuse jumped, the oven came to life. One more piece of classic (and still very useful) test equipment brought back to full operation.

[via Dangerous Prototypes]

THP Hacker Bio: Radu.motisan

July 3, 2014 by 46 Comments

thp-contestant-bio-radu-motisan

Here’s a great example of thinking big while keeping it simple. [Radu Motisan‘s] putting together a global radiation monitoring network as his entry in The Hackaday Prize.

The simplicity comes in the silver box pictured above. This houses the Geiger tube which measures radiation levels. The box does three things: hangs on a wall somewhere, plugs into Ethernet and power, and reports measurements so that the data can be combined with info from all other functioning units.

After seeing the idea we wanted to know more about [Radu]. His answers to our slate of queries are found below.

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Custom Controllers For Kerbal Space Program

July 3, 2014 by 17 Comments

kerbalKerbal Space Program is already a runaway indie video game hit, and if you ask some people, they’ll tell you it is the way to learn all about orbital dynamics, how spaceships actually fly, the challenges of getting to the mün. The controls in KSP are primarily keyboard and mouse, something that really breaks the immersion for a space flight simulator. We’ve seen a few before, but now custom controllers well suited for a Kerbal command pod can be made at home, with all the blinkey LEDs, gauges, and buttons you could want.

[Freshmeat] over on the KSP forums began his space adventures with a keyboard but found the fine control lacking. An old Logitech Dual Shock controller offered better control, but this gamepad doesn’t come with a throttle, and USB throttles for flight sims are expensive. He found a neat plugin for KSP made for interfacing an Arduino, and with a few modifications, turned his controller into a control panel, complete with sliders, pots, gauges, and all the other goodies a proper command pod should have.

[Freshmeat]’s work is not the only custom Kerbal controller. There’s a whole thread of them, with implementations that would look great in everything from a modern spaceplane to kerbalkind’s first steps into the milky abyss of space. There’s even one over on the Hackaday projects site, ready to fly Bill, Bob, and Jeb to the mün or a fiery explosion. Either one works.

Thanks [drago] for the tip.

Retro Gaming Console, Now With Internet Radio

July 3, 2014 by 2 Comments

RaspPi Retro Gaming Console with Internet Radio

Do you ever miss your gaming system of yesteryear? [yv3] did so he built a retro gaming console. Even though [yv3] likes his old school games, he didn’t want to be stuck listening to old school 8-track tapes while playing those games. The solution for him was to build a retro gaming console with integrated internet radio.

The gaming portion of the build relies on RetroPie. The RetroPie disk image contains all of the software and emulators needed to turn a Raspberry Pi into a dedicated retro gaming system. The RetroPie project supports a lot of gaming systems, [yv3] chose to include Atari, Sega Master System and Genesis, NES, SNES, and Turbografx-16.

Raspberry Pi Internet Radio manages the radio portion of this project and is set up to start playing automatically when the unit is powered on. There are 5 buttons to change the station, volume and settings. The radio stations are managed by a text file residing on the SD card. Audio from the radio can be directed to either the HDMI or the analog out of the RaspPi.

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Laser Piano Worthy Of The Band ‘Wyld Stallyns’

July 2, 2014 by 26 Comments

Laser Piano uses Arduino

[Robi] and [Kathy] from elecfreaks have put together a how-to article about a Laser Piano they just built. Instead of keys, the user breaks beams of laser light to trigger the sounds.

Several laser pointer diodes are wired in parallel and mounted in a box, cardboard in this case. The laser diodes are aimed at photocells that reside on the other side of the box. Each photocellis connected to a digital input pin on an Arduino. When the Arduino senses a state change from one of the photocell, meaning the beam of light has been interrupted, it plays the appropriate wave file stored on an external JQ6500 sound module.

[Robi] admits that there are some improvements to be made, specifically the trigger response time and the piano sounding too monotonous. If you have any ideas, please leave them in the comments section.

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The Old Ping-Pong Ball Levitation Trick

July 2, 2014 by 15 Comments

pingpongLev

[Jacob] has put a slightly new twist on the levitating ball trick with his ping-pong ball levitation machine. We’ve all seen magnetic levitation systems before. Here on Hackaday, [Caleb] built a Portal gun which levitated a Companion Cube. Rather than go the magnetic route, [Jacob] levitated a ping-pong ball on a cushion of air.

Now, it would be possible to cheat here, anyone who’s seen a demonstration of Bernoulli’s principle knows that the ball will remain stable in a stream of air. [Jacob] proves that his system is actually working by levitating ping-pong balls with different weights.

A Parallax Ping style ultrasonic sensor measures the distance between the top of the rig and the levitating ball. If the ball gets above a set distance, [Jacob’s] chipKit based processor throttles down his fans. If the ball gets too low, the fans are throttled up. A software based Proportional Integral Derivative (PID) loop keeps the system under control. A graph of the ball distance vs fan speed is displayed on an Android tablet connected to the controller via USB.

When [Jacob] switches a heavy ball for a light one, the lighter ball is pushed beyond the pre-programmed height. The controller responds by reducing the fan speed and the ball falls back. Who said you can’t do anything good with a box of corn dogs?

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