About Author
Joe Caldwell - electrical/controls engineer. I hope you enjoy this repository of my various projects and ideas. Thanks for looking.



Search


Projects

Tuesday
Sep072010

Night Sky Timelapse

I wanted to try this type of timelapse video since I first built my Arduino Intervalometer. Luckily the weather was clear enough that I had a good opportunity for night photography. I set my camera to take 30 second exposures at F8 and set the intervalometer to trigger it once a minute for 2 hours.

Using the Picasa movie creator mode, I set the transition to timelapse and the frame length to 1/24 of a second. This resulted in a nice smooth video of the northern sky rotating around the north star. Note: the video looks much better in full screen HD.

Sunday
Aug082010

Peggy 2 LED Matrix

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.

Wednesday
Jul072010

Acer Aspire TimelineX AS1830T-3927 Review

              

Specs:

  • CPU - Intel Core i3-330UM (1.2GHz, 3MB Cache) with Hyper-Threading
  • RAM - 3GB DDR3
  • HD - 320GB 5400RPM
  • Graphics - integrated Intel HD Graphics (128MB dedicated memory) 
  • Display - 11.6" (1366 x 768), 200-nit TFT, LED backlight, up to 16.7 million colors 
  • NIC - gigabit LAN
  • Wireless - Intel Centrino Wireless-N 1000 802.11b/g/n wireless LAN
  • Ports - VGA, audio-out w/SPDIF support, microphone, HDMI, 3x USB 2.0, 5-in-1 card reader
  • Battery - 6 cell, 5800mAh lithium ion
  • Dimensions - 11.2" x 8.0" x 1.0" – 1.1”, 3.1 lb 

Pros: 
Thin, light, good build quality, screen is bright and has good color saturation, screen's high resolution makes up for its small size, processor is powerful enough for general use, doesn't get too hot, great battery life (6+ hours), great port selection for small laptop, good keyboard 

Cons: 
Touch-pad isn't well demarcated from the wrist rest, the screen's vertical viewing angles could be better, no built in Bluetooth in this configuration

Overall I really like this laptop. It boots quickly and has generally snappy performance. It isn't the fastest at some processor intensive tasks like compressing audio and video, but that's to be expected for a low voltage processor. For general use like web browsing and watching videos it is perfectly adequate. I'll gladly accept some reduced performance given that this laptop doesn't get nearly as hot as other laptops I have used and it has fantastic battery life. I can get over 6 hours with the wifi on and the screen set to half brightness. The screen is sharp, has a good resolution, and isn't too reflective. The vertical viewing angles, however, aren't the best but they are hardly prohibitive to use.  The keyboard is responsive and comfortable to use which is a great asset for such a small laptop. I also really like the large port selection that Acer has provided. I've had larger laptops that had only two USB ports versus the three present here.

Probably the most annoying thing about this laptop is the touch-pad. It's not terrible; I just wish it was easier to tell by feel when you have left the touch sensitive area. Not a deal breaker, but annoying nonetheless. Another gripe is the lack of built-in Bluetooth in this configuration of the 1830. It is available on a higher end version, but I didn't deem it necessary enough to upgrade to the more expensive package since I don't mind using an adapter. Nonetheless Bluetooth modules are so cheap they should be standard in every laptop.

For a plastic bodied laptop this machine is very sturdy. The screen and main body are plenty stiff with little flex and the whole laptop feels very solid in your hands. The thing I like most about this laptop is its general portability. After owning a couple of bulkier laptops over the years, it's fantastic to carry around this little machine. If you are looking for a good general purpose ultra-portable laptop, you won't be disappointed with this one.

 

 

Sunday
Feb282010

Home Theater PC / Media Server Software

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
  • XBMC - media center
  • Boxee - media center based on XBMC but with 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. XBMC is fantastic for local playback but it can't pull content from the web like Boxee, however, I prefer XBMC's simpler interface. Both XBMC and Boxee 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.

Friday
Feb262010

Home Theater PC / Media Server Hardware

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

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.