Projects

Core i7 Sandybridge PC Build

2011-04-03T19:53:39Z

I last built a workstation about 2 years ago when I put together a Core 2 Duo box. It was solid machine and in day to day activities had more than enough computing power. Lately, however, I have been doing more video encoding and RAW photo editing and consequently decided that I needed a machine with better performance in those areas.

New PC Specs

Case - Antec Solo
Power Supply - Corsair CMPSU-450VX (450W), reused from previous build
CPU - Intel Core i7-2600 (3.4GHz)
CPU Cooler - Xigmatek HDT-S1284F, with ACK-I5363 mounting bracket
Motherboard - Gigabyte GA-H67A-UD3H-B3 (Intel H67 chipset)
GPU - ATI Radeon 4850, reused from previous build
RAM - 8GB G.Skill Dual Channel DDR3 1600
Hard Drive - 1TB Western Digital Caviar Black WD1002FAEX (64MB cache, SATA 6Gb/s)
Optical Drive - LG 22x DVD Burner (SATA), reused from previous build

Performance

For video compression tasks using Handbrake and Adobe Premiere Elements, this new PC is easily three times faster than my old Core 2 Duo machine. It is also noticably faster at image manipulation tasks, especially converting RAW files to JPEG.

Power Usage

Idle: 90W
Video Compression: 150W
Gaming: 205W

These numbers are roughly in line with my previous PC, although the idle is actually lower. This is a fantastic result for a significantly more powerful machine.

Noise and Heat

My last PC was a particularly quiet machine thanks to its case's usage of large, low RPM fans and noise reduction foam. Hard drive isolation was the only area where faltered. This time around I decided to go with a different case. In some of their cases Antec uses robust silicone cylinders to isolate the hard drive from the case. These worked so fantastically on my Home Theater PC Build, that I decided to get a case that featured them this time as well. This combined with some low RPM fans makes this case about as quiet as my last build, minus the hard drive noise. I even purchased some Silverstone noise reduction foam as well as silicone fan mounts to cut down the noise and vibration even further.

The Core i7-2600 is a 95W processor which isn't much heat for the Xigmatek cooler I chose to dissipate. In fact its fan never spins above its minimum RPM.

Arduino Word Clock

2011-01-09T00:06:22Z

I first saw a clock with this type of design on the Make Blog over a year ago. It is an incredibly clever idea, but the $1000 price tag is a bit much for my taste. I had seen a few attempts at a DIY version but most of them were still too complex or expensive to build. Needless to say when I saw this Instuctable I got really excited. It is based off of another Instructable, however, it simplifies the design and construction to the point where I felt confident that I could build it.

I followed the Instructable pretty closely, with the following exceptions:

LEDS: I got my LEDs from Evil Mad Science, which sells packs of superbright 5mm LEDs in various colors. This project requires a pack of 100 white LEDs. For current limiting resistors I used 470 Ohm instead of 1K Ohm. This allowed me more flexibility since I can dim the LEDs as much as I want, but I can never make them brighter. The LEDs I used are very efficient and only draw 4.8mA with a 470 Ohm resistor, so the maximum power draw for the clock will be about 150mA. Consequently power usage is not an issue since I used a repurposed cell phone charger as the power supply and it can provide 700mA at 5V.

Letter Mask: I had to use 4 transparencies stacked in order to get the mask dark enough. I also used a wider border for the letter mask to cover up some imperfections around the edges of my transparencies. For LED diffusion I used some translucent plastic folders that I found at an office supply store. I got a multicolor pack so that I could try different configurations and decided that a combination of one gray and one white folder cut to fit in the frame was the best looking and most functional choice.

LED Holder: Instead of a cardboard LED holder I used foam poster board. This is a much stiffer material and makes the holder much sturdier, however, it is also thicker so I had to make the light baffles 1" high rather than 1-1/8".

Circuit Board: Since the wiring on this project is fairly complex I decided early on that I wanted to keep the circuit board as simple as possible. In order to accomplish this I used two Radioshack breadboard matching printed circuit boards. These are great boards since they have power buses running down the sides of each board and they have plenty of room for the 7 chips necessary for this project. This made it very straightforward to scratchbuild an Arduino on one of the boards and then wire it to the other chips. Note: when building an Arduino in this way you need an FTDI cable which plugs into the 6-Pin header on the board in order to program the Arduino.

I mounted the boards side-by-side on a piece of acrylic to make it easier to work with. I also wired the board such that I could add a photoresistor in the future to allow for dynamic LED dimming (its wiring is bundled separately for later use as shown in the photos). Instead of wiring headers I just wired directly from the circuit board to the LEDs using multicolor wire to differentiate which word group I was wiring to (you can see each ULN2003A's bundle grouped together in the photos).

The size of these boards prevented me from trying to mount them inside the picture frame, however, mounting the boards on the back wasn't a problem. As shown in the photos I had use some stacked foam board as spacers between the back of the picture frame and the wall to keep the board from rubbing agains the wall. I also changed the power socket mounting from the back of the frame to the bottom by cutting a notch in the wood and gluing it in place.

Conclusion: The biggest problem I had with this project was dealing with a slightly imprecise LED layout. This resulted in some of light baffles partially blocking the wrong letters. After removing the problem baffles, however, I found that my diffusion layers worked well at making up for any discrepancies due to LED placement as well as reducing cross-letter light bleed to an acceptable level. As far as the code goes the only changes I made were done to make use of external pull-down resistors instead of internal and to clean up the code a little bit since some of the comments no longer made sense. I really like this project. It is not only cool looking, but it is useful as well.

Download Word Clock Arduino Code

Arduino - Parallax RFID Reader

2010-12-19T16:30:59Z

A few months ago I saw some Parallax RFID readers at Radio Shack on clearance and decided to pick them up since they were such a good deal. I have wanted to make an RFID related project for some time after seeing this episode of SYSTM.

This project uses a BASIC Stamp, however, which I have no interest in using. So when I found the following post at Gumbo Labs about using the Parallax reader with an Arduino, I was excited. Well I finally got around to trying out their code and it works perfectly. All you have to do is wire up the Parallax reader's power, ground, enable, and serial lines, upload the code and start reading tags.

Here are some pictures of my test setup. As you can see the reader's LED changes from red to green when it is reading a tag.

Peggy 2 LED Matrix

2010-08-08T17:06:22Z

The Peggy 2 is a 25x25 LED matrix kit from Evil Mad Scientist Labs. Ever since I first saw the Peggy kit I thought it was one of the cooler kits available. I finally got around to getting one of these awesome kits and it is a sight to behold. By far the largest kit I have ever built, it is also the best quality kit I have come across. The Peggy 2's circuit board is probably twice the thickness of a normal printed circuit board, a welcome feature for such a large board since the added thickness makes the board very rigid. You can purchase the Peggy 2 in a variety of kit configurations; I got the so called awesomeness bundle which includes a power supply, extra pushbuttons, and 640 diffused 10mm LEDs in the color of your choosing (white in my case).

The build itself took around 2 hours to assemble the control circuitry and another 4.5 hours to solder all of the LEDs. It's a bit of an undertaking, but when you're done it's a great feeling when all 625 LEDs light up. To program the Peggy you use the Arduino IDE and download the Peggy Library. I haven't experimented too much with it yet, but I did try out some of the demo programs from the library and you can see what the Peggy can do in the video below. I look forward to playing with this project a lot in the future.

Home Theater PC / Media Server Software

2010-02-28T18:22:38Z

Check out the Hardware portion of my HTPC.

The software setup for my new HTPC started with a clean install of Ubuntu 9.10. This went without a hitch and it was time to install the various software packages that I use to get my system in working order.

Network Sharing

Samba (located in the System -> Administration menu after installation)

In the Ubuntu repository this is called the system-config-samba package. This is a great GUI tool for setting up shares on a Windows network and allows me to view all the content on my HTPC on my Windows machines. Just input your Workgroup, what you want to share and who is allowed to view it. This tool makes this process much easier than editing configuration files. One thing that confused me at first was setting up user access; make sure to include the computer name of the user in the "Windows Username" field. For example "joe" didn't work, but "DESKTOP\joe" did.

Backup

Scheduled Tasks (located in the System Tools menu after installation)

Called gnome-schedule in the repository this utility allows me to run a backup script at a particular time. This is basically a GUI frontend for CRON and therefore much easier for a Linux novice like myself. I run a RSYNC script every night at 2AM which synchronizes the hard drive containing my media archive with another hard drive. I have found this a better backup solution than having a RAID array because it doesn't rely on any controller hardware or software. If one of the drives fails I can just replace it and copy the files to the new one. If I want to put the hard drives in another machine I can just take them out and plug them in, no other configuration is necessary. I realize there are drawbacks to this system, but I prefer something that I understand and know how to fix as opposed to other solutions that I have tried that have failed and cannot be fixed (ie. the Drobo).

Media Playback

VLC - media player
Miro - RSS media aggregator/player
Boxee - media center based on XBMC with great web integration

This is the standard media grabbing and playback package I have been using for a while now. I use VLC whenever I'm in keyboard and mouse mode to play video and audio files. Miro isn't perfect, but it's better than any other media aggregator I have tried. Boxee is fantastic for local playback as well as web content and it can be controlled via remote control. In the past Boxee was somewhat finicky when it came to your audio and video settings, but I have found the new Beta version to be much more stable.

Bittorrent

Deluge - my favorite torrent client, has the right balance of features and simplicity

Remote Control

LIRC - configured this for my Windows Media Center remote and it integrated perfectly with XBMC & Boxee

Accessories

GNOME Do - an awesome tool much like Quicksilver on the Mac, only for the GNOME desktop
pyRenamer - a fantastic, simple tool for renaming lots of files quickly

This setup served me well on my Studio Hybrid HTPC and is performing equally well on my new machine. I frequently try different software packages, but these core programs are always present on my home theater box.

Home Theater PC / Media Server Hardware

2010-02-27T00:38:01Z

My first HTPC consisted of some leftover parts I had laying around integrated into a Shuttle XPC barebones system. My replacement for that system was a Dell Studio Hybrid which performed well, was relatively quiet, and used little electricity. The main limitation for both of these machines were their reliance on external hard drives for storage expansion. I wanted to build something with more storage and upgrade flexibility.

The following were my goals for my HTPC/media server build:

Storage Expandability - plenty of internal 3.5" slots so I can reuse my current content storage drives and add more as needed in the future
Adequate Onboard Video - although not as powerful as nVidia's or ATI's products, Intel's integrated graphics are fine for home theater use when paired with a decent CPU, they also use less power, and their Linux compatibility is generally better
Low Power - this system will be on 24 hours a day so it needs to be as efficient as possible
Quiet - this will sit next to my TV so it has to be as quiet as possible

Parts

Antec Mini P180 Case (MicroATX Mini Tower)
Antec Earthwatts Green 380W Power Supply
Intel BOXDB43LD Motherboard (MicroATX, X4500 graphics, DVI, 6 SATA ports, 6 channel audio)
Intel Celeron E3300 CPU (2.5 GHz, Dual Core)
G.Skill DDR2 800 RAM (2GB)
LG 22x DVD Burner
Xigmatek HDT-SD964 CPU Cooler (with XIGMATEK ACK-I7363 mounting kit)

The Antec Mini P180 has 5 internal hard drive bays, plenty of ventilation (120mm & 200mm fans) and sound reducing panels. While this case is much larger than either of my previous HTPCs, I was more than willing to sacrifice space for a better all-around system. The Intel BOXDB43LD motherboard has decent onboard graphics (an upgrade over the Studio Hybrid's X3100), plenty of SATA ports for storage expansion and a decent assortment of AV ports. The Celeron E3300 processor fits my requirements for a processor that is cheap, powerful enough, and uses relatively little electricity. In order to make this build as quiet as possible I decided to use a fanless CPU heatsink. This is possible because the thermal dissipation required by the Celeron E3300 (65W) is low, the heatsink I chose is fairly large, and it should get plenty of airflow from the two case fans even when they are run at their lowest setting.

Assembly

The build for this machine was fairly straightforward. The case has enough room to creatively route cables behind the motherboard to minimize air blockage. I mounted the DVD burner on the bottom because the top slot's depth is limited by the huge 200mm top fan. I also rotated the CPU's heatsink from its normal orientation to take advantage of the top fan's airflow.

In order to take advantage of the SPDIF connection on the motherboard I built myself a coaxial SPDIF bracket using an old PCI bracket, a female RCA jack, some single conductor shielded cable, and a 3 pin female header. All you have to do is wire the center of the RCA jack to the pin of the header that connects to the signal pin on the motherboard using the center conductor of the cable. Then connect the cable's shield to the outside of the RCA jack and the ground pin of the motherboard header.

Input Devices

I have used this control setup for a while now and it works very well for me:

Apple Wireless Keyboard - great Bluetooth keyboard
Microsoft Explorer Mini Mouse - the BlueTrack system is the only one I've found that works consistently well on surfaces around a living room (wood, fabric, etc.), it has great wireless range & battery life, and this mouse is just the right size (small but not too small)
Logitech Harmony remote (set to emulate Windows Media Center remote) - I use the Harmony 610 which isn't the most advanced Harmony remote, but it also isn't ridiculously expensive

Performance

Superficially this machine performs about the same as the Studio Hybrid. I noticed slightly less CPU utilization when playing videos. This could be attributed to the improved graphics processor, although the X4500 does not support CPU offloading of video decoding for any format other than MPEG2.

Here's a performance comparison between this build (bold) and my Studio Hybrid (in parenthesis):

Boot Time - 0:55 (1:00)
CD Rip to FLAC time - 2:16 (3:41)
FLAC to MP3 Compression time - 1:16 (1:31)

Based on this info it seems that the Celeron E3300 is somewhat more powerful than the Core 2 Duo T5800 in the Studio Hybrid. Some of the performance difference can be attributed to the slower hard drive in the Studio Hybrid and the CD ripping performance was definitely affected by the much faster DVD drive in the new HTPC. However, the MP3 compression test relies heavily on CPU performance alone and shows that the Celeron E3300 is a solid performer.

Power Usage

Idle - 42W
Play 720p Video - 51W
Play 1080p Video - 55W
FLAC to MP3 Compression - 64W
Average over a week - 44.2W

Previously I determined that my Studio Hybrid used an average of 27W over the course of a week. This is 39% less than the 44.2W average used by my new HTPC, however, it doesn't take into account the two external hard drives I had attached to the Studio Hybrid that are now mounted internally. When you add in the 5W used by each of the two hard drives, it results in only a 16.3% power savings by the Studio Hybrid over my new HTPC. That's pretty good considering this new system is faster and uses desktop instead of laptop components.

Noise & Heat

I am very happy that all of my attempts to keep this machine as quiet as possible were very successful. In terms of absolute volume its probably about the same as the Studio Hybrid, however, the fans on this system are much lower pitched and therefore blend into the background noise of the room a lot more. Another advantage is that when under heavy load the fans don't spin up & generate more noise like they did on the Studio Hybrid. The default cooling is more than enough for the low level of heat generated by this system. The CPU stays around 38C and the hard drives stay under 30C at all times.

Check out the Software portion of my HTPC.

Remote Camera Shutter & Focus Controls

2009-11-23T01:13:18Z

In the process of building two intervalometers (analog, Arduino powered), I learned how easy it is to construct a remote trigger for a DSLR's focus and shutter controls. Both of those units featured manual controls for focusing and taking photos, but I wanted to build another separate project that would only feature that ability. This would allow the device to be much smaller and lighter.

For this build I used a 3"x2"x1" RadioShack project box, a 3.5mm stereo socket, and two momentary pushbuttons. In accordance with how my Canon Rebel XSi works, I wired the shutter trigger (red pushbutton) to the tip of the socket and the focus trigger (black pushbutton) to the middle contact. Then I wired the other side of both switches to the shield of the socket. I am a big fan of using a socket for a project such as this since I can now use a cable of any length or configuration as long as it has a 3.5mm plug on the end that plugs into the box. This is an incredibly simple build that works great and should come in very handy for all my remote triggering needs.

Hard Drive Speakers

2009-09-21T23:13:27Z

I first saw an article about hard drive speakers some time ago, but never thought about building my own until I saw this interesting project and decided to take a closer look. When I recently came into a pair of old hard drives, it was the perfect time to build my own set.

This is a very easy project to undertake. All that is required is to disassemble the hard drive (you will need some Torx screwdrivers) and solder two wires to the appropriate contacts on the hard drive's read head. These wires are then attached to the speaker outputs of your amplifier (I used my vacuum tube amplifier to drive the speakers).

After playing with the finished speakers I found that if I restricted the read head's movement by trapping the speaker wires between the two magnets at the base of the head's armature (as shown) the speakers would produce much cleaner audio. By restricting the read head's movement I prevent it from vibrating against the platters which can cause annoying scratching and rattling sounds. The downside of this is that you can no longer see the head's armature move with the music, which is a pretty cool effect. Regardless of how you construct your own set, hard drive speakers sound best with music that contains a lot of treble. Check out the video below to hear how my speakers sound playing some Bach.

Arduino Intervalometer for Time-lapse Photography

2009-07-20T23:07:30Z

Last fall when I built my first intervalometer and then used it for some time-lapse photography, the limitations of such a design became apparent. With an analog timer the circuit is limited by component values to function in a fixed way. The timing ranges cannot be changed without rebuilding the circuit and there is no way to be truly precise in your timing. A few months ago I came across this design for an Arduino intervalometer which is very basic and requires reprogramming for any timing changes. After some planning I decided to take the best features of my original intervalometer and combine it with an Arduino's flexibility to make a much more versatile intervalometer.

Key features to keep from the original were:

Camera interface isolation
Timing range options
Battery or AC adapter power options
Camera connection flexibility
Manual controls

Additional features that I wanted to add were the following:

Power supply flexibility
LCD readout
Start/Stop the timing cycle

In order to maintain what worked best in the original design I simply copied it directly over to the new version. I used the same relay isolation for shutter triggering, as well as hard-wired pushbuttons for manual focus and shutter control. I also used the same 3.5mm jack to connect to the camera as the original. For power I decided to use a coaxial power jack as I had previously but this time I did not place a battery inside the enclosure. Instead, I made an adapter cable with an N style coaxial DC power plug on one end and a USB plug on the other end. With this cable I can power my new intervalometer from any 5V USB power source (PCs, wall adapters, MintyBoost, etc). In order to keep this build as simple and inexpensive as possible I decided to use the Arduino Pro and a basic LCD for a total cost of $36. The Arduino Pro is the same as a standard Arduino, except it uses all surface-mount components and has no USB interface. This keeps the cost down and reduces the board size. The LCD was simple to wire requiring only +5V, ground, 6 data lines and a dimmer potentiometer input. The final features were all implemented in the Arduino code.

I ran into a few problems while developing the code for this project:

How to adjust the timing interval value
How to start & stop the timing cycle
How to switch timing ranges

For adjusting the timing interval I had originally planned to use pushbuttons, however, after playing with the idea I decided against it. I found that it was much quicker and more user friendly to use a potentiometer as a virtual selector switch. In order to do this I used the map function, to divide up the potentiometer's analog input values into the specified number of steps.

Starting and stopping the timing cycle was not as easy as it first appeared because the simplest way to wait a specific amount of time between events is to use the delay function. The problem with this is that while the program is delaying for the set amount of time, no other commands are being run and inputs are not recognized. To get around this I used a technique I found on the Arduino website which blinks an LED without using the delay function. Instead it sets a preset interval and then checks how much time has past using the millis function until enough time has gone by to trigger the desired event. This allows the processor to keep scanning the code while the timing cycle is taking place. Now if I want to cancel the timing cycle I can do so without resetting the Arduino.

To switch timing ranges I used this clever piece of code that allows you to use one button for two functions. When the button is pressed the Arduino keeps track of how long it was pressed. For short presses it performs one function and for longer presses it does another. I used this method to implement both timing range switching as well as toggling between set mode and timing mode as shown in the video below.

After getting all of my code together I assembled my new intervalometer in a 6"X4"X2" project box from Radioshack. This is somewhat oversized for these purposes, but it's cheap and readily available. Overall I am very pleased with this project. The responsiveness of the interface is very good and it triggers my camera shutter perfectly. The two timing ranges I preset in the unit are 5-60 seconds in 5 second steps and 30 seconds to 10 minutes in 30 second steps. These should cover the most common intervals I will use, and I can change them at any time if I have to. This is by far the most complicated Arduino coding that I have done and it was a great learning experience. Check out the video below for a demonstration of the device.

Download Intervalometer Arduino Code

Note: the LCD requires the updated LiquidCrystal Library, checkout this tutorial if you are using version 0016 or earlier of the Arduino software.

DIY Carolina Windom

2009-07-07T17:22:37Z

I have wanted to build a multi-band wire antenna for some time now and this past Field Day I had an opportunity to use a very good one. The Carolina Windom is essentially an off-center fed dipole (OCFD) that uses a portion of its feed line as a vertical radiator. I used one to make about a 100 PSK31 contacts on 20, 40, and 80 meters during Field Day.

The key to an OCFD's operation is the fact that there is a point on the antenna where the input impedance is approximately 200 Ohms at multiple frequencies. When fed with a 4:1 balun this provides a reasonable match to the standard 50 Ohm load that my coaxial cable and radio like to see. Even if the antenna doesn't provide a perfect 1:1 SWR over all bands, it keeps it low enough that a simple antenna tuner can compensate for any mismatch. The problem with OCFDs is that since the two legs of the antenna are of different lengths, the currents in each leg are out of phase. This means that in order to avoid feed line radiation, you should use a 4:1 current balun to compensate for this current imbalance. These are not readily available for sale, but can be constructed from kits. Here's a great article which describes how to wind your own current balun using this kit from Amidon. You can also buy an equivalent balun from DX Engineering.

The Carolina Windom, however, wants the feed line to radiate (at least a portion of it) in order to gain the vertical radiation and some performance. To achieve this the Windom uses a 4:1 voltage balun, which matches the antenna's leg voltages and then uses a separate 1:1 choke balun to isolate the feed line from the vertical radiator. Both of these baluns are readily available and relatively inexpensive.

The first step in constructing my Carolina Windom was to cut the antenna wire to length for an 80 meter version. I used these measurements from Radioworks, who sell pre-assembled Windoms, but other sites also show measurements and formulas for cutting a Windom for any band. My Windom has the same 133ft overall length of a traditional dipole, but is divided into 50ft and 83ft legs instead of equal lengths. Since this antenna will be used for temporary setups such as Field Day and the PA QSO Party, I didn't make it out of heavy duty wire, instead I used insulated #14 stranded copper wire. This wire is a good compromise between strength and weight. Construction of the Windom is very straightforward; simply solder one end of each wire to opposite sides of the 4:1 balun and attach insulators to the other ends. For the 4:1 voltage balun I used the W2AU 4:1 and for the 1:1 choke balun I used the W2DU inline-HF, both of which are available from Unadilla. These are well constructed commercial baluns that work well for these purposes. In the picture I do not have the choke balun connected since I did not have it at the time, so in its place I created a poor man's choke balun by coiling about 10 turns of my RG-58 feed line.

In order to test the antenna I set up my new fiberglass mast to about 25 feet with the Windom on top. While this isn't an ideal height, it was fine for a test. I connected the feed line to my radio and tested the SWR. I was able to get a match using my Icom IC-703's internal tuner on all of the HF bands. Since the 703's internal tuner can only deal with SWRs of less than 3:1, this means the antenna is performing as expected, providing a decent match to the radio on all the HF bands. For a further test I tuned around the 20 meter band. Hearing a special event station in Maine, I gave him a call and he came right back to me. Not a bad first test, getting into Maine with 10 watts. This is exactly what I was hoping for, a solid performing multi-band antenna that I can use for temporary operations. Wire antennas are very simple and cheap to build, and this one is a great project for any type of station.