Halloween Circuitry

October 31, 2004 at 5:26 pm

I managed to steal a bit of time in the past few weeks to build some circuitry for Halloween. I’d hoped to do something with pneumatics, but that didn’t happen, so we had to settle for a few smaller things.

I’m also using this as an opportunity to teach Sam how to solder.

We started with converting a typical “Home depot” motion sensor into an inline version. That’s pretty simple – take a extension cord, and wire in the motion sensor inline. A little heat-shrink tubing, and it was done. The motion sensor is hooked up to the power for an old boom box that I have, which is playing spooky music from my MP3 player. Come up the walk, and the music starts playing.

Te second project is a bit more elaborate. Right next to the front door, there’s a dummy with a pumpin head sitting in a chair. In his (its?) lap, there’s a bowl with a full-size Hershey’s chocolate bar, and a sign that says “Help Yourself”. If you do help yourself, the eyes of the pumpkin light up and a bell rings. This is all based on detecting somebody trying to grab the candy. I explored a few methods of doing this – there are some that use RF techniques to detect the change in capacitance as somebody approaches, but they’re notoriously finicky. I decided on an IR approach, and was lucky to find a site that sold the Sharp GP2D15 IR sensor. You’ve probably come across this sensor in the hands-free faucet in a public restroom. This sensor is very easy to use – it generates a signal when something comes within about 10″ of the sensor. The output of the sensor isn’t powerful enough to power a relay, so an added 2N2222 transistor does the amplification. That relay runs the bell, and there’s a separate solid-state relay that turns the eyes on.

Finally, I bought an Edirol UM-1X Midi interface. This connects to our Roland digital piano, and is used to play back spooky organ music (Bach, mostly) through the piano’s built-in Pipe Organ patch.

More bicycle test rides…

October 3, 2004 at 9:38 pm

I took advantage of the wonderful early October weather today to do some more test riding.

I’d plannd on going to Bicycle Center of Issaquah, but today was “keep people away from our businesses” day at Issaquah, so after spending 20 minutes in traffic and 10 minutes on my bike trying to get to the store, I gave up, and drove into Seattle to Greggs at Greenlake.

After doing the usual “what are you interested in dance”, the salesman pulled out three bikes for me to ride:

  • A Specialized Roubaix (Elite Triple, I’m fairly sure)
  • A Trek Madone 5.2 (Treks replacement for last year’s 5200)
  • A steel-framed Bianchi (apparently no bike shop has a nice Bianchi in my size to ride – this is the second shop that put me on a $1500 bike when I’m riding other bikes that are quite a bit pricier).

I rode the Roubaix first. After a short trip out and back when I re-discovered that the standard method for determining the proper seat height works poorly for me (felt like I was sitting on the seat tube), I headed out for a quick loop, up some hills. The Roubaix frame uses aluminum for most tubes, except for the fork (hard to buy a bike without a carbon fork these days), and the downtubes in the back triangle. This results in a frame that is very responsive – I could sprint very well, and it felt really good up a short hill. The problem is that the frame is pretty stiff, and – to me at least – leads to a ride that is harsh. Its not as bad as the ride of the all-aluminum bikes that I rode about 7 years ago, but it’s still enough to be objectionable. Sprinting perforance isn’t high on my list of requirements right now, so my overall rating wasn’t very high on the Roubaix. Better than my current bike, certainly, but too harsh.

I rode the Trek next. Trek is, as far as I can tell, one of the few manufacturers to bring the carbon fiber frame to the masses, and the bulk of the feedback I’ve heard has been quite positive. It is, however, about $800 more than the Roubaix, so it’s going to need to be pretty good. Unfortunately, Gregg’s only had it in a 58cm frame, and a 60 is closer to what I’ve been riding, but I took it out anyway.

I took it out on the same route as the Roubaix. It only took about a block for me to start smiling, and I continued smiling up the hill, down the hill, and then back up the hill on a different route. It’s not quite as stiff as the Roubaix was when sprinting, but the ride is incredibly good. All the low-level “road rumble” is soaked up by the frame, and the edges are taken off the harder bumps. For me, it seemed to climb about as well as the Roubaix, and I did the hill twice to see how it would do on th steeper stuff. The geometry is much quicker than the Roubaix, and while that means you have to pay more attention, it makes it more responsive, which I like.

With the exception of the price, there’s really wasn’t anything I didn’t like.

I next rode the Bianchi. It’s pretty close in the feel to my current bike, but with a harsher ride. Blech. Though the bike is only 4 pounds heavier than the Trek (22 pounds vs 18 pounds), it rides like it’s lots heavier. Though the fact it was my fourth trip up the hill may have been a factor, this time the climb was *work*, rather than fun. Given the price differential, it’s really not a fair comparison, but it did reinforce to me that I don’t want a steel frame.

So, that’s two more bikes off my “must ride list”. I’m getting a 60cm of the Trek to ride in a few weeks, and I want to ride the Giant before I make a final decision. If I do go with the Trek, I have one final decision to make. Trek has an option called “Project One” where you can, for a few $$$ more, customize a few things on your bike, including the paint job. For example, I could get a bike that looks like this:

My big surprise today was how much difference I could tell between the bikes.