Saturday, November 16, 2013

DIY Pentax Wired Remote


A sneak peak of the finished device

After the purchase of my Pentax K-7 a few years ago I began to experiment with long exposures, specifically "bulb" exposures. Bulb mode, sometimes abbreviated with a "B" on camera bodies, is a shutter speed setting that allows for extraordinarily long exposure times. When enabled, the shutter stays open as long as the shutter release button remains depressed. This is great since we can exceed the exposure times supported by most DSLR and SLR bodies. For instance the K-7 can do exposures automatically up to 30 seconds, but past this the bulb mode must be used. It is slightly annoying, however, since the shutter must remain depressed for the full duration of the shot. See how I solved this after the jump.

Wednesday, May 22, 2013

The importance of "measure twice, cut once"

Although others may tell you something over and over again, you don't really learn a lesson until you experience it yourself. Here is an example of when I learned the importance of measuring twice, and cutting once. Although this case didn't actually involve cutting, it did involve purchasing a CPU cooler for a very toasty HTPC I was building. The chip was a 3.2 GHz Hyperthreaded Pentium 4 (Socket 775) and it ran incredibly hot (82W max TDW). I wanted a quiet box since it was being used in a HTPC environment, so I purchased a Cooler Master Hyper-212+ CPU cooler. The pictures don't do it justice. This cooler was simply massive. In fact, I can't in good-faith recommend you use this cooler with a vertical motherboard orientation (despite CM saying this is OK) due to motherboard warpage (shhh..."warpage" is a word, don't question it).

CM Hyper-212+ with two fans mounted. Both fans had rubber isolating hardware

Racing Pedals

One very simple mod I've done to my 2005 Mazda 3 is adding "racing" pedals. These pedals do not replace the existing ones, but rather cover the ones in place. They look great, and tend to have less slippage in wet weather or with slippery shoes. The rubber covers of the existing pedals are easily removable for bolting. 

I purchased this look-alike kit from eBay for less than $25. I was overall very impressed with the machining of the aluminum, and had next to no problems with the set. Sets can be found for both automatic / manual transmissions, and can be found with and without the Mazda logo.

The set, all together!


Air Conditioning for the Man Cave

Every now and then I find myself facing a project with a little less electricity and a little more elbow grease. After a family friend donated a window air-conditioner, I decided it would be a good idea to install it into my un-airconditioned man cave in my families garage. This is home to surround sound, an LCD TV, a few game consoles, and an HTPC. It gives my friends and siblings a place to hang out and be loud without bothering the folks in the main house. It's also a nice place to stay when we have company at home. The downside is that during the summer it can get pretty roasty out there. The process looked something like this: 
  • Cut a hole in the sheet rock (check for wires!)
  • Cut stud
  • Install frame
  • Cut outside hole
  • Install air conditioner
  • Install bracing
  • Install trim
  • Mud, sand, paint, and touch-up

Halogen -> Xenon Upgrade

Despite some cleaning, polishing, and buffing, the headlights on my 2005 Mazda 3 were still quite dim on the road. This was partially due to age and haze in my lenses, but mostly due to the terrible orange/yellow halogen bulbs. 


Original Halogen Headlights


Tuesday, May 14, 2013

Rainbow Goose

A little while back a friend of mine donated a beautiful Grey Goose bottle. With the frosted glass and clean-etched goose, I couldn't let this beauty go to waste. I had a few RGB LED's laying around from the 2012 Cal Poly EE Banquet table centerpieces. These LED's had 3 diodes inside along with a small microcontroller to fade between the colors and create intermediate tones. They're quite nifty, and pretty cheap at that. They can be found from SuperBrightLEDs

Wanting more brightness, and a little more control over the color changing, I purchased a 3 watt from gybbshop on eBay. It's a pretty neat unit with the following features:


  • Aluminum-backed heatsink for dissipation
  • Built-in controller circuit with small SMD components
  • Power requirements closely matches a USB port (DC 5 - 5.5V, 150 - 600 mA)
  • Built-in infrared receiver and microcontroller
  • Small footprint (28mm) with mounting holes
  • Brightness control as well as on/off button.

Picture courtesy of eBay seller gybbshop

I purchased two of these boards (along with some green LED's for my traffic light project) and all worked perfectly upon arrival. After removing the existing leads, I soldered the leads from a 5V 750 mA wall wart phone charger onto the board. I cut some aluminum foil to closely match the diameter of the Grey Goose bottle. Slathered with thermal grease, the aluminum-backed PCB and aluminum foil couple to make a decent heatsink for the LED. While the the PCB should provide enough thermal dissipation, I didn't want to fry anything when running at full power.

After a quick test fit, I hot glued the whole assembly in place. The concave bottom of the bottle provides plenty of clearance for the bulbous LED and large IR receiver. Plug it in and voilĂ ! We now have a gorgeous customization multicolor Grey Goose bottle. The modules respond to the same IR codes, so a dozen or so of these could be placed behind bar and all be controlled from one remote.

The final product! For those curious, the original contents of the bottle were replaced with plain water in order to comply with Housing regulations.


Monday, May 13, 2013

Caltrans Love

Early last quarter I helped clean out a storage room in the ATL here on campus. The Advanced Technologies Lab is home to some supercomputing power, machine shops, car garages, and conference rooms. While cleaning out one of the rooms, I came across this beauty:


CalTrans traffic light, complete with sun-damaged ABS plastic and a decade of dust and dirt!

Find out what I did with it after the jump.

Sparks!

Sometimes after a week of midterms, having a bit of unadulterated fun is required. For the longest time I had a 1 Farad 12V car audio amplifier laying around my room. I decided it needed to be...investigated. For starters, the actual capacity is nowhere near 1 Farad. After some calculations for Tau, the time constant which determines charging, the capacitance came out to be around 0.66 farads. Not terrible, but certainly not a full farad! 

Two engineers, one high-capacity capacitor, and a GoPro HD. What could go wrong?! The capacitor was first charged to around 23 Volts, disconnected from the power supply, and shorted with an insulated paperclip. Check out Nolan's page for a high-speed video (240 fps viewed at 24 fps).

It was great seeing my reaction in slow motion. And really terrifying how slow my reaction time actually is.

A closer shot of the action.
One neat thing to note: the automatic reflexes of my eyelids were thousands of times faster than the reaction of my hand. Huh...

Meraki, a Cisco Company

Meraki MR12 AP

While researching access points I stumbled across an interesting company: Meraki. Now a Cisco subsidiary, they provide hardware which is completely cloud-controlled. Once configured from their management page (which is in the cloud, NOT local on the device), the device connects to the cloud and pulls its configuration. While this sounds like an interesting concept, I immediately thought of the a very critical list of cons.


Is it a Dell, or is it LSI? Both!

Last summer I picked up a couple of Dell SAS 6/ir PCIeX controller cards. Out of the box, these are capable of Raid 0/1 and have no on-board memory. What Dell tries to keep hush hush is that these cards are simply a re-branded LSI SAS3081E-R, capable of both raid and simple target mode. 2x 8 channel SATA HBA's for less than $50? I think yes!

Dell SAS 6/ir without mounting bracket


Wednesday, May 8, 2013

Welcome!

Like many other technology aficionados, I've tried before to start up a blog; I've tried out Google pages, Blogspot, and even good old FreeWebs (circa 2002) but none of them seemed to stick. Since those days I've purchased a domain, and been much more active in my technology documenting. Blogger rolls all the features I want into a nice package, and so here goes nothing!

As of this writing, I am a 20 year old Cal Poly Electrical Engineering student. Growing up in the Easy Bay of California, I had a semi-eclectic childhood including a mishmash of running my own computer business (TechOBrien), attending Diablo Valley Junior College for highschool, and raising farm animals through 4-H. Somewhere along the way I became interested in technology, computers, electronics, hardware, and many many other things. This Blog serves as my personal documentary of tinkerings: projects, products, classes, and ideas. It will serve a dual-purpose of updating interested readers on the various projects I'm involved in, and giving me an opportunity to write about my life.

The first few posts will likely be back-posts of old projects of mine. Once I get the blog "up to speed" so to say, I will add some of my newer works and begin a more regular schedule of posts. You can expect things such as computer projects, custom hardware builds, electronics design, and new product reviews. I'll also be posting about the various courses I'm taking at Cal Poly.

Thank you for visiting, and enjoy!