January 27, 2008
PowerNowD v1.00 is released out into the wild. This marks the last release of the software. If others want to take it further, they may do so with my blessing. But since the ‘ondemand’ kernel governor is now working pretty reliably, that seems to be the wave of the future. I’m glad that I was able to create something as useful as powernowd, and I’m happy with the way it turned out. From the beginning it stayed true to its purpose and thus is a fast, efficient program that does one thing and one thing only.
The only changes over v0.97 are some valgrind cleanups (pedantic ones, no real bugs), and a small correction from the debian/ubuntu packages that uses strtoll to read the stats out of /proc/vmstat instead of strtol for long running guests on 32-bit systems.
It was very important to me to finally release a 1.00, even after all this time. It provides a bit of closure, and it also means that I kept my word as I promised back in 0.90. It also opened my eyes to the problems people go through when maintaining even a small oss package for a linux distribution. My hats off to all the distribution maintainers out there.
I will say this, there is something incredibly cool about having a bit of software you wrote running on hundreds of thousands of computers all over the world, which is what happened when Ubuntu started installing powernowd by default on all their systems. Note however that as of feisty, (I think?), even though they install powernowd, the powernowd init script actually loads the ondemand governor and uses that if it’s available, and only runs the real daemon if ondemand can’t be loaded. This means most people aren’t using powernowd anymore as part of Ubuntu. Still it’s a very satisfying a fulfilling feeling to know I wrote something useful.
Here’s hoping I can do something else nearly as useful in the future.
Posted by john under linux | Comments (2)
January 15, 2008
Well, it finally works. For a while, anyway. I built a simple train garden with a loop around the outside and a windy piece of track that went through the center of a very sparse town. I eventually used photoresistors, two bright white LEDs shining at them, and the basic stamp’s RCTIME function to measure the resistance to detect when the trolley got to the end of the track. It worked pretty well for a while, but then something happened to the 5V transformer i was using to power the switching circuit and now it doesn’t work anymore. I’ll fiddle with it some, but now that I know what I need to do it should be a lot easier next year. The trolley also had problem with my hodgepodge of track that I’ve gathered over the years. Half the time the circuit woudl work fine, but the trolley would get stuck on the curved track and just stop moving. I may have to come up with a mod to this trolley and it’s -very- weak motor. Or, at least, invest in some new, cleaner track.
I also build some model houses for the garden for the town. It was the fist time since i was like 15 that I’d put together a model. I’d forgotten how much fun it was. I wound up using some Faller “Super Expert” Polystyrene glue that came in a bottle with a long needle tip, and man, it sure made putting those building together very easy. MUCH better than the old bottles of Testor’s glue I remember using. It’s probably due to the tip, which was very good at getting just the right amount of glue where I needed it. Good stuff.
All in all, it was a great experience, and I’m very glad I did it, even with the frustrating hours of work that went into getting that damn auto-reversing circuit to work. But work it does, and I was able to create something from scratch, and I learned quite a bit about myself in the process.
Posted by john under trains | Comments (0)
January 2, 2008
The holidays went quite well here. Spent the first part visiting family, and having a great time, had to work part of the week, Saw Vince and Kristina on Friday, and then took a trip out to Deep Creek lake with some of my college friends and spent New Years there. That trip went very very well, and Katy and I spent a lot of time catching up with friends who we really haven’t had much of a chance to connect with recently. It was very important for Katy, because sh got to really know some of the other women in the group which she never really got a chance to do since we’ve been together. My car survived the trip, but it’s getting too old to handle strenuous mountain climbs and icy snow coming down mountains too. Need to budget for a new car sometime soon. It’s sad though, it’s been nice not having a car payment for the last 2+ years.
The unfortunate thing about the holidays is that I didn’t get a chance to finish the train garden. So that means that I still need to finish it and then have my family down later to see it. I redid the whole circuit from scratch and moved the relays far away from the microcontroller, and that seemed to make the auto-reversing part of the system work, but the IR sensors still weren’t detecting when the train hit the end of the track. I replaced the IR sensors with magnetic reed switches, and hot-glued a curiously strong magnet I got as an early Christmas present to the bottom of my trolley, and the whole thing worked great!
… for about 5 minutes, and then the trolley ground to a halt. The light was still on, so it was getting power, but it wasn’t moving. I put it on the regular track, gave it full juice, and it still wouldn’t work. I finally removed the magnet, and with a little coaxing, it finally started to work again. Something about having a semi-strong magnet near a DC motor makes it lose torque and then stop. I understand on one level why that might be (could be interfering with the magnets in the motor), but I don’t fully understand why. Sigh.
Anyway, I’ll need to redo the circuit with IR sensors again, and then maybe I’ll be done. Hopefully by this weekend.
Posted by john under General | Comments (0)