Rick Swift & Apple & Embedded I make things. Sometimes, I’ll talk about it here.

My Gorram Frakking Blog

Watching TV in your car

So, I'm coming home from work yesterday, and I come up on this pickup truck with an extended cab and huge tires. I can see through the smoked back window that they've got two screens showing video, one in front of the passenger and one in the center for the rear seats.
We get to a red light, and I get close enough to where I can see what's playing. I snapped a picture, if you want to see. In case you can't tell, it's a girl on her knees in front of a guy.
They had the volume up loud enough that you could hear the cheesy music in my car.

Improved Motor Platform

Wow, it’s been a long time! But in an ongoing effort to avoid studying and homework, I'm mucking about with the Ichibot and associated pages.
Even though I haven't gotten very far with Ichibot, I’ve decided to build a new, better mechanical platform for it. I’ve designed the chassis, and am currently looking for way to get it machined. I’ve also purchased the necessary hardware, pictured below (click the images for a larger version, or the links for a huge version).

Bearings, shafts, collars, pulleys, belts, motors Hardware partially assembled
Full-sized image of separate parts Full-sized image of partially assembled parts

Full-sized image of separate parts Full-sized image of partially assembled parts
The new Pittman motors (part GM8724S021-R1) are much better than the old JameCo motors. They are 12 VDC motors with 60.5 : 1 reduction gearheads and 500 CPR encoders. They were $195 each, and I’m a little concerned that I ordered too much gear reduction. Some people on the robotics lists have all suggested I’ll be happy to have the torque, and that the output shaft speed is sufficient. We’ll see.
The new chassis will look something like this. I need to redo the CAD. I’ll post complete drawings and make the files available.

CAD view of new chassis
Underside of new chassis

EE120 "Is not a Math Class"

Yeah, right.
I like my professor, I really do. He's personable and funny, and a good lecturer. EE120 is "Signals and Systems" at UC Berkeley. He has told us time and time again that we're in engineering, and we don't like to do math, and that this is not a math class.

Maybe it's just me, but I don't see anything but math on that board, do you? Click the image for a view of the entire blackboard(s).
Now, to be fair, this lecture was pretty cool. He demonstrated how the sinc function can be used to perfectly reconstruct any band-limited continuous-time signal from a sampled version of that signal (assuming it was sampled above the Nyquist frequency, of course). Very, very cool.
The pretty graph in the middle shows how the individual sinc functions line up with each other and sum to the original signal. It's evident from the graph that at least the sample points are correct (the analytical expression for that is on the board to the right).
Still, not a math class?

Why Apple Fucked Up with Aliases

Aliases used to be this thing in the Mac OS, prior to Mac OS X, that allowed applications to remember where a file was located. More importantly, if you moved that file, the application could still find it. They worked across network volumes, too, automatically mounting a volume if necessary.
With Mac OS X, Apple recommends that an application store URLs to reference files. The problem with URLs is that they are just fancy pathnames to files, so if you move or rename a file, they break. To be fair, I've seen documentation that suggests CFURLRefs should be used only for transient storage of a file reference, but this gets abused across the board.
Safari's downloads window, for example, is guilty of this. Try donwloading something, moving it, and then finding it via the download window. You can't. And Apple puts the blame on the user by popping up a message saying, "Safari can’t show the file 'foo.pdf' in the Finder because it moved since you downloaded it."
Fuck you, Apple. So what if it moved? You can find it, almost always. You had tried and true, superior technology, and when you shitcanned or otherwise drove out all the true Macintosh engineers, replacing them with NeXT Unix weenies, you got rid of that good technology. Everyone knows engineers brought up on Unix are lazy, and don't give a rat's ass about the user. Well, that attitude shows through in Mac OS X.

God Does Not Exist

It's simple. God is a made-up idea. Made up by men. A crutch used by humans to ease their fear of the unknown. A sword wielded over countless millions to subjugate. It is time to grow past the notion.
OpinionJournal has a surprising number of editorial pieces in support of a non-secular America. I can't think of a more stupid idea.
Take your heads out of your asses; quite burying them in the sand. There is no such thing as God, no "invisible man in the sky." Learn some tolerance, open mindedness and most of all, learn to think for yourselves.