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Archive for the ‘how to’ Category

It’s 5:40 am and I just got out of the robotics club. I’ve got class in a couple hours so in the interest of being able to retain information tomorrow, I will forgo a blog post for tonight and instead write something tomorrow.

Today (very) briefly: Got wireless working, cut out a whole Arduino, fully planned jacket stitching, finished new laser mount (version 3.0), went to a cool tech talk, looked into cheaper communications packages.

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Posted by admin on January 14, 2010

Build18: Day 3

01-13-10

Today was a fairly productive day, though not as productive as I would have hoped. I made some headway on all aspects of my project, but didn’t get very far in on any of them.

I was able to delegate some of the sewing for the jacket to my wonderfully crafty girlfriend and she was able to sew on both sets of LEDs. Unfortunately, I wasn’t able to stop by her apartment so I don’t have any pictures to upload yet. Fear not, though, as I will have some tomorrow! I have yet to design the circuit for the Lilypad Arduino, XBee carrier and power supply, but that should come very soon (hopefully tomorrow, er today. I really need to stop writing these at 2-3am).

On the XBee front, I was able to get my two XBees communicating with the help of some fellow Build18 participants. It’s a great feeling when you have two computers talking over hardware you configured, even if it’s the most unnecessarily complex IM protocol/client in existence. Now that my communication problems are over with, I can set my attention back to writing code and designing the circuits needed to interface the two major subsystems.

Despite the absence of two of the three lasers I will need to complete the project, I have begun designing the laser mounting system. This is a nice challenge for me as I don’t often get to use my mechanical design and machining skills. I’m a bit out of practice, but I drafted a design by hand, modeled it on the computer, and eventually milled some prototypes. Unfortunately, the Roboclub shop was out of drill bits large enough to support the laser. I learned this only after spending four to six hours milling the parts and saving the large hole for last. Needless to say, I was upset. Thanks to friend and fellow Robotics Club officer Dan Shope, I have a new design that will be significantly easier to machine and much more likely to be finished tomorrow. I will upload the drawings of my first prototypes tomorrow and hopefully some pictures of the new design as well.

One part of my project that I haven’t focused much on yet (with the exception of keeping up these fairly regular blog posts) is the publicity aspect.  I’m beginning to see myself advertising my project more and more which is kind of cool. I attended a meeting of the ECE department’s Student Advisory Council with some other Build18 participants (not entirely because of the free food, I swear!) and gave a little spiel on my project. I’m getting better at making my elevator pitch for the project; I can describe it well in about 45 seconds to a minute. An interesting thing I learned at the meeting was that one of the Build18 sponsors (Qualcomm, I believe, but it could also be Google or Sparkfun) would be sponsoring an award for one of the projects. I’m super excited! There are a lot of cool projects so it’s good to see someone will be recognized. I also learned that although there is a project demo session in 2-3 days, there will be a final unveiling at the end of the year. This means that I might have a chance to put some real effort into the aesthetics of my project which I’m also really excited about! Can you say vacu-forming?

I apologize if this post seems a little scattered, but  it’s about 3:20am and I’m not quite awake any longer. In any case, expect pictures of the jacket in progress, drawings (and possibly pictures) of both the failed and not-so-failed prototype laser mounts, and an update on the XBee circuits

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Posted by admin on January 13, 2010

Build18: Day 2

01-11-10

This is going to be a shorter post than yesterday because not much progress was made.

Today was the first day of classes so I had a good chunk taken out of my normal hacking time.  In any case, I wasn’t able to get past some problems I’ve been having with the XBee chips and getting wireless communication to work. Despite that, I acquired (thanks to my ever-patient girlfriend) a hoodie to use as the base for the turn signal jacket and got some planning done for the laser mounts that I’ll have to machine either tomorrow or the next day. Additionally, I got the acrylic I’ll be using to turn the point from the laser pointers into a line that will be visible on the street.

In order to have something pretty (aka a picture) to post, here’s the test circuit I promised yesterday (click the picture to read the annotations better).

Test Circuit for turn signal code

Test Circuit for turn signal code

If there’s interest in a schematic, I can post one. I think it’s pretty clear from the picture what connects where, but if you’d like a schematic, let me know in the comments. It’s a bit too late right now for me to draw one up because I’m sure I’ll make a mistake in my sleep-deprived state.

That’s all for today. Expect a breakthrough on wireless communication and some pictures of the jacket coming together (knock on wood) tomorrow.

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Posted by admin on January 11, 2010

Build18: Day 1

01-10-10

Today (err, yesterday now) was the first day of Build18 and the official start of my project.

Look at all these sweet parts!

Look at all these sweet parts!

All of the products I ordered from Sparkfun came in (the lasers from Amazon were delayed due to weather problems) so I decide to get started on making the jacket portion.

Although I wasn’t able to get the XBees working, I did make pretty good progress on the rest of the programming needed to run the turn signal jacket. It’s a pretty simple program right now, just blinking the left or right side LEDs and turning on the associated indicator LED. I plan to add the wireless functionality and possibly a few more advanced blinking settings after classes today.

For those interested, here’s the code so far. Don’t forget to auto-format (ctrl-t) after you’ve copied it into the Arduino IDE.

Tomorrow I’ll post a circuit you can use to unit test parts of the code.

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Posted by admin on January 10, 2010

This is going to be a short post, but I thought it might be a good idea to update you all with the Bill of Materials I sent off to the admins of Build18. (Note: There will be some part exchanges as we’re trying to get as much stuff as possible from Sparkfun, one of the Build18 sponsors)

Bill of Materials

Bill of Materials (click for larger version)

This isn’t the final B.O.M, but it gives you a pretty good idea of what I’m doing. The original lasers I purchased are no longer sold on Amazon, but this one looks like the ones I got (although I can’t vouch for the actual laser itself). One thing to note is that my budget for this project was $250. I’m pretty sure that with less prototyping-oriented gear and a longer build period, the cost of this project could easily go under $100, possibly even cheaper depending on your source for the lasers.

I may post some additional minor updates before I get back to school and actually begin working on the project.

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Posted by admin on December 26, 2009

Pittsburgh in winter in definitely not bike-friendly. Snow, ice, and salt are all enemies of the bike. The first two can be overcome with the help of better riding techniques and ice tires, but the third brings up categorically different problems.

Salt is a steel bike frame’s worst enemy.

I built my bike for free at FreeRide. Unfortunately, the only frame available that fit me was almost completely sanded down. This presents a problem because metal without a finish + salt = rust! (Yes, rust factorial). I plan on painting my bike, but I won’t be able until the summer when paint will actually dry.

The problem: rust. The solution: electrical tape.

First, you’ll want to put a couple rounds of electrical tape over any brake-line holders you may have on your bike. This is just to make sure no salt or water gets in through any gaps that may arise because of the bumps.

IMG_1976

After you’ve covered the brake-line holders, you can now proceed to covering the frame with electrical tape. You will probably want to cover the top tube first because it’s the easiest. Start from one end and do a couple of loops before beginning the wrap. You’ll want to make sure the tape lays flat on the tube. Electrical tape is great because it has a certain degree of stretchiness which will help keep a nice flat surface. You will want to overlap the tape about half the width with each turn.

IMG_1983

IMG_1982

Once you’ve done the top tube, go ahead and continue with the rest of the frame. I would recommend removing your tires and chainring before taping the frame because it makes things a lot easier. Unfortunately, I did not have the tools available to do so.

IMG_1986

The finished product:

IMG_1993

IMG_1995

IMG_1997

As you can see, I didn’t cover the head lug because it was really more pain that it would have been worth and every try came out looking bad.

General tips:

  • Isolate the frame as much as possible, it’ll make things easier to tape
  • Wipe down the frame with a rag beforehand
  • To get tape residue off when you decide to paint, I’d recommend Aircraft Remover

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Posted by admin on February 1, 2009

Unlike the majority of picture frame hacks on the internet, this guide from Hack A Day teaches users how to build and program a digital picture frame from scratch. This is a great tutorial because it not only teaches the reader how to build the frame, but also teaches some useful functions like reading from SD cards, PIC programming, and working with common graphical LCDs.

DIY Digital Picture Frame

“We set out to build a 100% DIY, scratch-built digital picture frame. Our frame has a 12bit color LCD, gigabytes of storage on common, FAT-formatted microSD cards, and you can build it at home.”

This project presents bit-twiddling and PIC programming in a more accessible fashion than many other tutorials on the net with a great end result.

Additional fun with digital pictures frames can be found here.

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Posted by admin on January 12, 2009

As a budding fixie rider, I’ve often  found myself searching Craigslist daily for the best deals on parts for the bike I’m building. This is kind of cumbersome because I have to scan through a whole bunch of posts before I find something that’s actually close to what I’m looking for. I figured that there had to be a better way for me to keep track of what was popping up in craigslist.

The answer is RSS feeds.

An RSS feed is sort of like the updating headlines you sometimes see on news websites. We will be using RSS feeds to keep an updated list of a certain search term on Craigslist. This method can be applied to any RSS feed in particular, but a tutorial on this use was requested of me. To start, go to your local Craigslist site and type in the search bar what you want to keep track of. For this example, I’ll use turntables.

First go to your local craigslist site and type in whatever you’re looking for in the search box to the left.

step1

Then scroll down to the bottom of the page and click the orange RSS button on the lower right. Also, if you wanted to track only those items in a certain price range, you could do so by typing in your range at the top of the page before clicking the RSS button.

step2

You will then be brought to a new page that will look a bit different than the normal Craigslist page. Make sure you’re using Live Bookmarks, then click the “Subscribe Now” button.

step3

A small window will pop up asking you what you’d like to name the feed. I’d suggest something short, but descriptive because you will only be able to see about 16 or 17 characters once it’s in you toolbar.  Finally, check to make sure that the folder selected is the “Bookmarks Toolbar” folder. This way, you wont have to dig through your bookmarks to find your feed.

step4

Click subscribe.

step5

Congratulations, you now have an auto-updating Craigslist RSS feed!

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Posted by admin on December 18, 2008