Posts Tagged ‘projects’

How to modify an old entertainment center to fit a new HDTV

Sunday, November 28th, 2010

How to modify an old entertainment center to fit a new HDTV

DC Adapter Swap

Tuesday, November 23rd, 2010

View this photo set on flickr

USB access point was originally powered by a 5V DC wall adapter. You can purchase additional wall and car adapters online for ~$20.

Simple modification allowed me to plug into any USB port for power. Allowing me to use any of my existing USB wall and car adapters. I removed the old DC barrel jack and soldered in a new jack that matches a USB to DC power cable I purchased.

Can purchase the DC jack to USB cable here: SparkFun Item 8639
The DC jack can be purchased here: SparkFun Item 119

Guide: Weapon Counter Display Overlay

Monday, August 9th, 2010

Took a lot of trial and error, but I think I came up with a method to make a display overlay that I can be proud of.  Thanks for the help James Hodson(jlhR2).

Click More Info for the full guide.

The overlay is meant to go on top of my ammo counters, but also looks good when used alone with a light behind it.  The overlay is made of several transparency sheets layered atop one another plus a sheet of tracing paper toact as a diffuser.  Could probably substitute tissue paper.

The image files to print out are below. You will need to re-size the images to fit your weapon before printing.  If printing at home, be sure to buy transparency sheets meant for ink-jet printing and not laser printing.Ink-jet printable transparency sheets have a rough surface to print onto.

I find my photo printers T-Shirt Transfer mode gives the best print out.  It takes some trial and error, but set the Print Quality to high for best results.

Halo Reach

Click Picture to download full size

Halo General Purpose – James Hodson (jlhR2)

Download full size here:

There will be four layers, from bottom to top there is the tracing paper,two black transparencies, and the color transparency.

The tracing paper and the black transparencies need to be cut so the numbercan shine through (xacto knife).  If not using an ammo counter circuit, youmay cut in whatever number you like.

DO NOT cut the color layer transparency.  This is what colors any light shining through to the proper hue.  It also makes photographs when unlit look amazing.

Tip: I first cut a piece of paper the size of the hole I wanted then taped it down so I could have something to trace with the knife.

Below are pictures of building up the different layers. In these photos onlya single layer of black is used.  You can see that the light gets through a bit in areas that are supposed to be black.  This is why we use two layers ofblack.

Clear tape is used to hold the layers together and keep them aligned.

Have fun~!

DIY Recoil Action

Wednesday, June 9th, 2010

Goal here to add the sensation of recoil to a prop rifle gun.  I have seen it done with compressed air and motor pistons, but neither are easily synchronized with electronics and capable of rapid firings for full auto fire.  Leaves me with the third option of using a solenoid.  To fire a solenoid with enough furiosity to kick the gun into your shoulder involves some serious power requirements.

I did a dry run yesterday and came up with this circuit.  The solenoid is rated 12-24V and 3 lbs force.  Using the circuit below it was weak at 18V, fully actuated at 27V, and actually had some kick at 36V.  I am not sure I want to take it higher.


View Full Size

The next step is to design a circuit to use a lower battery voltage. Three C cells should be sufficient. The 4.5V from the battery would be stepped up and charged across the capacitor. The control circuit would be connected to the solenoid circuit through a optoisolator and a mosfet.

Animated Light Controller

Sunday, March 14th, 2010

Using a spare attiny2313 to control some solid state relays. Four channels total, two outlets are always on.

100_5635.JPG 100_5636.JPG 100_5634.JPG

Here is the schematic. The LEDs are mis-routed to the same path as the relay control wires. Turns out the LEDs sap current and don’t allow the relays to trigger properly. Leave the LEDs disconnected and all is well.


Rockband Stage & Light Kit Mod

Sunday, January 31st, 2010

Sorry, I do not have full writeup for this project. Here is a photostream of the mod.

Rock Band Mod on Flickr

Pretty much what I did was take an off the shelf strobe light and swap it for the one built into the fog machine. Re-wired a ps/2 keyboard cable connecting it to the liberated rock band strobe light. Now I can use the strobe light with the game without dragging out the fog machine.

Also added override switches on the fog machine so I could activate both the strobe and fog machine outside the game.

Presenting the Halo Energy Sword~!

Friday, November 6th, 2009

Full Sword Lit

I knew what I wanted to do was design a circuit that would be similar in function to the star wars sabers that fans build. That meant animated lights running the length of the twin blades, an accelerometer to gather motion data, and sound playback for startup and swing sounds.

What I ended up doing was designing a circuit around an ATMEGA32 controller chip.

Hit more info for details.

This is a summary page, additional notes are on the forum.

Original Project Page

Full Sword Lit


I knew what I wanted to do was design a circuit that would be similar in function to the star wars sabers that fans build. That meant animated lights running the length of the twin blades, an accelerometer to gather motion data, and sound playback for startup and swing sounds.

Full Sword NonLit

What I ended up doing was designing a circuit around an ATMEGA32 controller chip. The ATMEGA32 offered me everything I needed at the time, which was serial communication and analog in/out. There was also the benefit that I am familiar with this chip and know it’s documentation well.

Tech – Lights

The lights consist of 66 color changing blue/red LEDs. The lights are connected to the ATMEGA32 via 5 digital outputs and 2 analog outputs. Blade Corner Close up LitThe 5 digital outputs control the ignite and extinguish animations of the blue LEDs, while an analog output controls the red via PWM.
A unique wiring is used for the color changing LEDs. Bicolor LEDs have 3 leads, a common lead, then one for each color. The normal wiring method is to connect resisters to each color’s lead. I used a single resister on the common lead which makes it impossible to light both colors at the same time (forward voltages are different for each color). But by using the microcontroller’s PWM function, it is possible to make it perceived that both are lit at the same time. Playing with the frequency of the PWM on the red, I found the sweet spot where the red fades up and the blue fades down. This gave the appearance that both were lit at the same time for a purple glow.
LED blade constructionThe effect is set to fade in and out with a timing that matches the barely audible hum that the in game energy sword produces. On top of the fade effect, there is also a flicker effect that is controlled by the raw output of the analog accelerometer.
For a while I left the PWM on during sound playback, the blade had a neat “lock-on” effect that would turn the blade solid red during a swing. However, the PWM created an annoying feedback on the nearby audio amplifier. So now the sword is solid blue during a swing.

Magifier on Accelerometer

Tech – Motion

The motion chip is an ADXL203 dual axis accelerometer. At first I threw out the idea of an accelerometer because of the surface mount soldering that is required, but later found surface mount soldering by hand is attainable. There are some good tutorials on Sparkfun.
This accelerometer has an analog output (force = voltage level) and is connected to A2D inputs on the ATMEGA32. A programming loop monitors the input then if it detects sufficient motion, the program will fire up the sound subroutines. Motions that do not have sufficient motion for a swing are passed to the lighting functions. The raw data from the accelerometer is given directly to the PWM routines and added to the fade value. Since low motion analog data is susceptible to noise, this gives the appearance of the lights flickering in a truly random effect. This also gives the user the impression that they are in control of the flicker. Slowly waving the sword around gives a unique flicker effect.

VMUSIC2 connected to Controller circuit

Tech – Sound

The sounds were recorded from in game and saved as MP3s. Some work was done in an audio studio to clean up the sounds for playback. At the heart of my circuit is the Vinculum VMUSIC2 MP3 player. This sound module has come to be known to be the best sound effect solution for prop makers. It has a USB port to read a USB memory drive and a serial wire so it can be controlled by your own microcontroller. It can play both MP3 and WAV file types with full bit rate of the MP3.
The only down side of the VMUSIC module is the size. It measures 2.5″x1.5″ which could be considered small, but is difficult to fit into the handle of my prop.
I also considered writing my own playback program or using sound recording chips. Neither of them could compare with the playback audio quality that the VMUSIC module provides.

Tech – Amp

The audio amplifier was added as an afterthought and it shows in the design. This is one area that screams improvement needed.
The current solution is a AN7513 1W audio amp chip. This is a small IC that can directly power a small speaker.
The problem is an issue of both volume and sound distortion. The amp is capable of driving the speaker kinda loud, but at volumes louder than 50%, distortion becomes apparent. This limits the speaker volume to household venues.

As an alternative, I added a headphone jack to the design. An wearable small amplifier is connected for usage in noisier locations. Because the headphone output is directly from the MP3 player, it can reliably be amplified to very loud volumes.


To ensure the highest quality prop I teamed up with an individual named Sean Bradely. Sean is best known for featuring his previous halo energy sword that he built. His previous sword consisted of a molded handle, flat plexi blades, and glowing EL wire. It was regarded as the most accurate fan made prop energy sword in existence.
I had a mostly functioning circuit when Sean approached me. We decided that we were working toward the same goal and a partnership would allow us to use the best of both our talents to achieve an even more accurate prop.
He had been in the process of designing a new energy sword for quite some time. For the new sword he would have dimensional blades instead of being flat. In this cavity he planned to insert LED rails to maximize the light given off by the blade. My circuit would be perfect for him and his blade and handle molds would be perfect for me.

Sean's Vacuuformer in action

Vacuformer & Blades

One of the tools to create the dimensional blades was a vacuuformer machine. It was assembled by Sean for this and other projects. I won’t go into it much, but it is an amazing tool to form plastic. More info.

The blades were created on this machine around a wooden buck that Sean cut and sanded into the shape of the blade.

Handle close up assembled

The Handle

The handle is made from an impact resistance resin and was sculpted by Sean. It houses the circuits and has the structural support for attaching the blades.


Handle lighting. This was simply a matter of size and time constraints. We wanted to add lighting to the handle and I had designed pins on the circuit to control this lighting. The idea was that the lighting would be bicolor blue white LEDs wired similar to the way that the blue red LEDs were wired. A mix of LEDs directly on the surface and fiber optics for pinpoints of light. The circuit could even blink or fade the handle lights in a pattern to reflect the MP3 player status. Problem came down to fitting it inside the handle along with everything else tightly packed in there.

Buy a Pager MotorVibration Feedback. Add a pager vibrator motor inside the handle. The motor would be connected to the same PWM signal sent to the blade lights. This vibration would give the sword the missing “hum” effect. The PWM signal is sent in parallel from two controller pins to two driver pins, allowing the circuit to control two devices with the same signal.

Halo Energy Sword

Tuesday, March 24th, 2009

If you read about that sort of thing, you may remember last fall Master Replicas announced a Halo Energy Sword that would feature similar functions as their ForceFX Lightsabers (powerup/down sounds, motion activated sound, animated lights). The promised release date was the holiday season 2008.
There is another company that makes realistic Halo toys, this is the same company that made a plasma pistol and plasma rifle that are superb. They also announced an energy sword in 2007 with a 2008 release.
Here we are in 2009 with no product from either company. I had to do some major digging to learn both these products were canceled and will never be released. Killed for either licensing or safety concerns.

Based on the demo videos released by Master Replicas, it seems possible for me to create my own prop with similar capabilities. Hit more info for details.

Update: August 2009 – See completed project details.

This project is fairly large for me and needs to be broken down.

Modeling and Plastic Molding

Most of the Halo models are freely available and have even been converted into a format that can be printed out. Ready to be cut, folded, and glued into a 3d shape. I plan to adapt this process to recreate the sword’s handle. So far, I have the blade handle shape created and I filled it with expanding insulated foam for strength (paper is not strong).

The next step is to cut this model in half and place on a vacuuform machine (which I don’t have). The resulting plastic shape will be glued or screwed together to create a hollow plastic handle (to house the electronics) that is durable and ready to be painted. There are plans available online for home vacuuform machines that can be built for less than $50 and use a shopvac.

Lights and Acrylic

I need to experiment with some scale arcylic pieces to determine the best method of lighting an acrylic blade, but the goal is to animate some LEDs that illuminate the blade so that the blade will appear to extend and retract.

Diffuser Options
The acrylic has a fiber optic like property when light shines near the edge, the light will bounce around inside of the arcylic until it finds an imperfection to illuminate. A diffuser is used to catch the light.

  1. Sanding the acrylic, will give the acrylic a frosted look.
  2. White adhesive laminate, this is best suited for a multi layered acrylic that is lighted internally

LED Placement Options

  1. A row of LEDs on the interior or exterior edge or both. The LEDs can be covered by a strip of black or white tape. May create “hot” spots along the edges.
  2. An array of LEDs sandwiched between acrylic on either side. Will use hundreds of LEDs and give the most even light.

Whatever I end up doing, the LEDs will be animated. I have a circuit in mind that will do the extend effect very nice, but I am also looking into a microcontroller (depends how the sound effects tests go). As far as I can tell, I will be the first hobbiest to attempt something like this for a Halo prop.

Sound Effects

Besides the lights, this is the most interesting part of the project and is fast becomming the most difficult. I have seen on various forums people harvasting the sound board from electronic sword toys and reusing them for this purpose. I was unable to find any local stores that sold appropriate electronic toy swords. I can find several online but refuse to buy anything before I use it in hand, so I know the light patterns and sounds it will make (don’t want my halo prop making pirate shouts, haR!).

My next option is compiling my own sound effects and playing them back in sequence. This is a lot easier said then done. The actual sounds can not be dumped from the game only recorded while it is running. The best quality sounds I have found are actually from that MR demo video. I plan to record this to some .wav files for the sounds they demonstrated.

As far as playing them back, that is an interesting request. I have a few options including MP3 players, voice chips, and microcontrollers. An MP3 player would be too slow and would have limited playback options, similar story with the voice chip. That is why I am leaning toward a microcontroller. A microcontroller could be loaded with converted wav files and play them back at a sample rate, it could also be used as a substitute for the light circuit and give access to more animation patterns.

The problem with using a microcontroller is more an issue of experience with sound playback. I’ve only done it once before on an 8085, which I don’t have. What I do have is a dev board left over from my college days for an ATMEGA32 chip. There is a great website available for enthusiests of the atmel microcontroller manufacturer and the free software suite, AVRstudio. The website is AVR Freaks and after doing some searching I found some free source for playback of converted wav files. The assembly source is for a different processor, but checking the spec sheets, they are not only compatible, but my chip offers more features and four times more flash memory (32kB vs 8kB for more sound clip storage).

To bad for me, before I left college I accidently erased my serial bootloader. So now I need an ISP programmer ($40). While I’m at it, I might as well also purchase some extra crystals and power transitors so I can build up a stripped down dev board for a prototype circuit. Here is an ordered list of the planned evolution of my program.

  1. Get the sample code working playing back the sample wav file
  2. Get the sample code to playback my own wav file
  3. Call the assembly sample code from a c coded main loop
  4. Playback two wav files back to back
  5. Playback a wav file in a loop
  6. Playback starts on button press, playback stops on button release
  7. Put it all together: Wait for button press, playback powerup sound, playback on sound in loop, wait for button release, playback powerdown sound, wait for button press.
  8. Add timer interrupt to control LED animations

Motion Sensors

I am not really sure, what I will do here. This is more of a future development. I have seen motion sensors before, they consist of a week spring surrounded by metal, movement causes the spring to contact the metal sides. I could use something like this and set an interrupt to triggure additional sound effects (swoosh, swish).

Some other options, tilt switches and accelerometers. I don’t think a tilt switch is what I am looking for, in the tilted position, the switch is always one.
The accelerometer has some technical hiccups. It will detect motion very nicely on all 3 axis and the cheaper models are sensitive to small motions (less than 3G). The problems come in that this is an analog device and to be cost effective, only is available in surface mount packages. The analog side can be handled by the sound microcontroller and the ADC inputs, but the surface mount… that will need some more thought.

Battery Format

Probably a 9V for now, may expand to a recharchable NiMH or an impossibly small lithium poly.

Current Progress

Current progress and project notes can be found on my forum.

HTPC Project

Friday, February 6th, 2009

A writeup of choosing parts for my black box media computer. Based on my htpc project from last year.

Component List 2009

There is the list. That’s all you need, now go and watch some videos on your custom built xbmc box.

I did get into a few arguments over the component selection. In the end I won. Read on for my rationalizations.


The case is the first decision to make and determined how the rest of the build will progress. I set out a number of goals to achieve.

  • HD video playback capable
  • Small footprint (going in an entertainment center)
  • Near silent operation
  • Under $300 price tag

These goals kept me from going crazy with vacuum displays and built in remote IR receivers or file server racks. I went with a simple case that I fulfilled my needs. A microATX case and a low profile design.

The low profile design causes other issues and limits how much can be crammed in the case. Only MicroATX motherboards may now be considered. All pci boards will have to be low profile or have the ability to be made low profile. The case also only has room for one internal 3.5″ drive and one external 5.25″ drive.


I knew I wanted Nvidia graphics because XBMC was incompatible with ATI at the time (xbmc is now compatible with near everything). I also knew that I wanted onboard graphics.

On board graphics was decided on necessity and pricing. Realizing full well that upgrading the graphics after the initial build is very difficult. The only way to upgrade your graphics is to replace the entire motherboard. The graphics chipset also handles many none graphic operations like your network adapter and must use the RAM of the motherboard. This is called shared memory and can be set to more or less in the bios settings. More is better, so be sure to give your system as much memory as you can while keeping in mind the maximum memory that can be shared.

There are a number of advantages to onboard video.

  1. You do not have to accommodate any extra space for a graphics card.
  2. There are deals to be had with onboard graphics.
  3. The graphics don’t overheat or have a need for a separate fan.

The only other thing I looked for in the motherboard was the proper internal port headers and rear ports available. HDMI, serial, USB, etc…


The last major decision was the cpu. Something to fit a LGA 775 port. I ended up on a celeron. 35W and 65 nm, this thing runs cold. The 1.85Ghz single core may not sound like much, but this is not a gaming machine. It is more than powerful enough to run any video encoding I can throw at it.

On top of that, this line of chips is overclock friendly. So if I ever feel the need for some extra kick, all I would need to do is upgrade the included fan for additional cooling.

Hard Drive

Who needs one? That’s where the 4GB flash drive comes in. There is a custom bootable build of xbmc available on sourecforge for just this purpose. The system runs linux, but you see no linux. The system boots straight to xbmc with zero configuration.

Later on I did switch to a spare small hard drive I had so I could run more applications in the background. Sigh… Ubuntu…


A soundcard is a must. Onboard sound cannot compare with a real sound card. After I finished the build, I plugged my sound system into the onboard audio and compared to the sound card, the output was much quieter and almost muffled.


Not mentioned are the DVD player and RAM. Besides the latency and price, I didn’t really care about these selections.

After putting it all together

Assembly was painless and XBMC LiveUSB V2 runs all hardware as expected with default settings. Only the remote required configuration, needed the lircd.conf file updated.

The cpu is only as powerful as it needs to be for HD playback, but also has a lot of overclocking potential for any future needs.

Star Trek Communicator

Thursday, January 22nd, 2009

Got the idea in my head after I finished watching all seven seasons of Star Trek Voyager for the second time that it may be possible to create a functional comm badge. It would function as a bluetooth headset of sorts for a cellphone. Their are plenty of micro sized bluetooth headsets, but they only work when close to your ear.

I see three different ways to implement this idea:

* First, take an existing micro headset pcb and add an amplifier.
* Second, there could be a wire from an ear phone to the comm badge, the mic and controls would be in the comm badge.
* Third, ditch the comm badge all together and go with a TOS communicator and use a bluetooth speaker phone module. *preferred

Updates will be on the forum, link.