Tuesday, 6 January 2009

Day 4 after killing my TV - Boxee and XBMC

A friend at work 'trimbo' sugguested I look at "XBMC", and its offspring, Boxee.

Boxee is a branch of XBMC, and it includes some special code to better integrate with sites like Hulu. I finally managed to build it from source (no Windows binary as yet), and get it running to sample its UI and streaming. So far, its just plain buggy, but it is only in an 'alpha' state, which is usually feature complete, yet buggy as hell, so that fits the bill.

I only got it barely running around midnight, so I'll be trying it out on the living room PC tomorrow. The integration is nice of course, but I'm hoping the hulu video player (or Boxees implementation) isn't a piece of trash like the stock flash player is. According to the intrarwebs, flash does everything in software, even YUV to RGB translation, which means my poor 2.8ghz P4 is left gasping for breath if a flash video goes fullscreen, yet a XVID rip of BSG is smooth as glass at full screen.

Seems odd that a p4 couldn't handle the YUV/RGB conversion, but perhaps it's all written in bad scalar C code, and not MMX.

I'll report on the quality of Boxee as it gets some real use (and hopefully a real release) as the TV season picks up again after the winter break.

Posted by tim at 12:32 AM in General Stuff

Sunday, 4 January 2009

No more satellite TV - day 3

My wi-fi network decided to 'get strange', which means it's data through-put dropped out, and latency spiked. I have no idea why. So instead of fussing with finding a new router or upgrading to 802.11n, I went under the house and laid some ethernet cable to the living room from the DSL modem.

I also upgraded the DSL to 3M/768, but I'm only seeing 2M down. :( I do have a 30 day trial, so we'll see if it improves. I also fixed up the wiring under my house for my phone and DSL. (it used to run into my window).

Having ethernet of course improves the speed, and the streaming videos work much better. Some sites have better quality than others.

For the highest quality, I can always download a show over zune or xbl marketplace.

I see this as the ultimate in early adoption. OTA, Satellite, and cable TV will live a long time, but already I see all this content showing up online. In my mind, delivering shows over the internet makes more sense, they still get to control the content, and they get 'closer' to the end consumer. A executive at a major TV network can get numbers on exactly who is watching their show, which ads generated clicks, and so on.

Posted by tim at 3:44 PM in General Stuff

Wednesday, 31 December 2008

Reason for Zune 30s dying: a busted if() statement.

As reported on the Makezine Blog
while (days > 365)
{
	if (IsLeapYear(year))
	{
		if (days > 366)
		{
			days -= 366;
			year += 1;
		}
	}
	else
	{
		days -= 365;
		year += 1;
	}
}

So, imagine it's Dec 31, 2008. days = 366, year = 2008.

Still in the while loop, it gets past the first check (IsLeapYear), then it sees that days isn't greater than 366... it's EQUAL to 366. It leaves that block, and boom, hits the while loop again... with all the same values! Rinse and repeat.. forever.

the '=', should be a '>='. Though I would simply caution against using while loops during computation. I've personally been burned by this in my own code. Better to have a loop that can escape after a 'reasonable number of cycles', or always make sure (in this case) days is being operated on in every code path.

Microsoft's official statement: wait a day. That would make days = '367', and everything will work again... until 2012. Will they bother to fix this? I dunno. I find it hard to believe I'll be using my Zune in 4 years. The battery will have died, and something more awesome and cheaper will have come along by then.

In the end, it's Freescale code, and apparently untested. Personally, I'd be loathe to write any sort of date/time routines, just because the gregorian calendar is so convoluted. Though if I ever have to, I'll be sure to write a unit test that tests my date/time functions over the span of every day for at least 5 years of input.

Posted by tim at 7:52 PM in General Stuff

The day the Zunes stood still.

Yes, my Zune30 has locked up. At this point, I think all Zune30s have. (according to various Zune websites, it's widespread)

Nothing to do but wait on a official fix. Some people are opening their zune to disconnect batteries. The official forums are a mob of angry insane people. Calling news stations, blaming MS for cancer, 'threatening' to buy an iPod, and so on.

Yes, it sucks, I get that. MS is working on a fix. If they had said "well, FU guys, you're out of warranty, so buy a new one", At that point, I think it'd be OK to get pissed.

I'd like to point out that ipods get deprecated INTENTIONALLY by apple, and no one seems to raise a fuss. So when a company screws over customers in plain sight, it must be OK.

Posted by tim at 1:16 PM in General Stuff

Saturday, 27 December 2008

Abandoning broadcast TV

My satellite TV bill is about $97. There's a lot of content there. However, I don't think I'm getting my monies worth. I don't watch that much TV any more.

I've gone through my catalog of shows I've set my DVR to record, and have found most of them online in one form or another. Hulu, Joost, and the big 4 all stream their shows online. Many other networks have a smaller collection of videos. However, my favorites can be watched online completely legally. Worst case, I might have to go buy an episode or two at Zune or xbox video marketplace.

So my DSL will get a bit more use out of it, this will end up saving me $100 a month for more important things, like food.

I'm gonna move my older computer (which was a 2.8ghz P4, plenty fast) into the living room next to the projector, and use that as my video provider.

This will effectively mean I loose HD, though this I believe is temporary. The ball is already rolling, more and more content will be online as time marches forward. Already I can watch a lot of hulu content in 480p with improved audio, and ABC delivers shows in a adapting stream that improves quality from 'bad VHS tape', all the way to 'crystal clear' depending on bandwidth available. I was able to watch Lost at around "75%" of their full HD. It looked just like what I was already getting on the satellite HD channel.

I checked with my ISP, and for $40 more, I can probably go to 3Mbit down, which I might do. Many of you are probably thinking I'm getting robbed at $110 for 3Mb DSL, though I have to remind people that I have business class DSL, and a static IP in order to run my email and web servers<. For now, I'm gonna see how this flies with my 1.5Mb.

Posted by tim at 2:44 PM in General Stuff

Sunday, 28 September 2008

Just hit 45mpg.

I've had a few runs between work and home that are getting 45mph *average*. Generally, it's over 40 for the commute. Not too shabby. My volvo averaged 26mpg.

Diesel is only $4.00 right now. So it's still amazingly cost effective compared to gasoline. I'm getting about 500 miles between fill ups.

I still hope to get the bio-diesel reactor going, but now I've got too many projects going. I need to just finish these things, not to mention save some money for equipment.

Posted by tim at 7:00 PM in General Stuff

Yet another dream project: my own TARPS.

I have baggage pods for my Long-EZ. Plenty of room in just one of these, I'm thinking I could make a 'recon package' for the backseater to play with. Think about it... a gimbal mount could be made with some stepper motors, a DSLR camera could be stripped and mounted on it, strap on a decent telephoto lens, and the whole thing be controlled via USB. For a few more.. uh, thousand dollars, a uncooled thermal imager could be on the same platform. Overkill perhaps, but so...very...cool. I could imagine a backseater having great fun snapping 12(20?) megapixel 20x zoom photos of anything remotely interesting on the ground during a flight.

I'm not sure how to get the camera to 'track', might be an image processing problem, or maybe it could guess using current GPS position, airspeed, and gimbal orientation.

It's probably rife with issues, camera shake, targeting, user interface, and so on. Still, seems like it'd be fun to work on.

Ah well, maybe after I've close all my other open projects down...

Tuesday, 2 September 2008

New Car

I just bought a 2009 VW Jetta TDI. Already getting 45mpg in it. Awesome stuff. It's quiet, smooth, and powerful. Why doesn't everyone drive one of these?
Posted by tim at 2:16 PM in General Stuff

Tuesday, 19 August 2008

New elements installed

I picked up new elements from Kiln Elements. Stan was very helpful and even made up custom coils for my FX23 that were 7 ohms instead of 8's and 9's. Because my SSR is rated for 50 amp, going to 7 ohms nudges up the amp draw a tad, which should help be reach cone 10 easier (or at least with a margin)

Friday, 8 August 2008

I need more lock washers and K-Locs

So my starter was getting flakey. I was fearing the worst, might need a new starter, or at least a new relay.

Nope. Turns out the signal wire (the one that tells it to "start") was just dangling on the bolt, with no nut! The thing had backed off nearly an entire inch in one of my flights.

I'm always amazed at how screw + nut + vibration = lost nut. I would think it would 'vibrate' randomly, but for some reason, it tends to favor 'unscrew and fall off'. Which is why, I presume, they invented lock washers, or nuts like the K-Loc.

I think I need to make a sweep of all the nuts on my plane, and make sure they are k-locs or have lock washers.

Maybe next time, I'll read the circuit diagram.

My kiln kept popping the breaker. a 50 amp breaker, and it was supposed to only be a 25 amp kiln. This puzzled me for a long time, since the mechanical timers worked fine, and never popped the fuse. So I started to poke around and noticed the resistance in my setup. It was 3 ohms. That means 240V /3 Ohms = nearly 80 amps! I then remembered I could get the original circuit diagram from Cress, and looking at that, I noticed the coils were wired as 2 series resistors in parallel (4 coils total). After rewiring and checking resistance... 10 Ohms. Ah, much better, 240/10 = 24 amps.

I have no idea why my SSR didn't melt down or asplode(other than the active fan on it), or my circuit breaker didn't pop immediately. I'm thankful it didn't cost me another SSR. at $35 each, they are sorta pricey.

Moral of the story: check your wiring diagrams kids.

In other news, the kiln is working! The software needs a tad more automation to be useful. That'll be the next step.

Tuesday, 29 July 2008

New SSR, now with cooling.

I strapped a CPU fan to my SSR. I ran some low duty cycle tests on it for about an hour last night, and it is still ticking. The first one without heatsinks died in about 20-30 minutes.

Hopefully it now has enough heat dissapation.

I'm now wondering if I should make a *new* controller with a fan speed input and a 2nd thermocouple just to monitor the SSR health. The last one failed 'open' (i.e. power shut off), but if it fails closed, that could be very bad.

Ah, the trials and tribulations of automation.

Posted by tim at 11:28 AM in General Stuff

Saturday, 26 July 2008

New EFIS computer booting from Compact Flash

In the end, it was simple, just let the installer do it's thing, including NTFS file system. What I thought needed to be done was stick with FAT32, but that was nothing but problems. So in that regard the advice of the masses of internet posts was amazingly wrong. I did learn a bit about MBRs and boot records, but I would have prefered just to get things working. I currently have a 1Ghz fanless "Nano-ITX" board booting off compact flash in about 45 seconds. I think I can reduce that further by trimming some services, and using Minlogon, which supposedly speeds up logins. As it stands though, I do have a working computer that would probably hold up until SSDs get cheaper (and in stock, can't find a OCZ core anywhere)

Also, there is a tool to try called EWF, or EFW.. er, anyway, it makes the drive read only, which means the CF will last just that much longer. The main task now however is to mount this thing back in the plane.

Tuesday, 22 July 2008

Kiln controller now two-way, but eats relays

I've done some low duty cycle tests, and was able to fry my SSR (apparently, it needs a heat sink beyond 5-8amps), while I was also able to melt and/or boil off solider from the coil-relay replacement. That means it got to 400 degreesF at the contact point! Insane. I've tried beefing this up (more conductor should reduce resistance), but I've still had it fail. Might have to make a new board with large area for heat sinking. Or just wait for the replacement SSR to show up (which I will attach to an old CPU heatsink+fan).

The control software is coming along slowly. I'm probably going to make it more of a follow-the-curve sort of system instead of a true feedback or PID. Right now I'm doing everything I can to increase safety, like auto shutoffs and timeouts.

Thursday, 17 July 2008

Kiln controller almost works....

So very close. I have the kiln controller reading ambient temp, reading the type-s thermocouple, and sending UDP packets with its updates. I need to get it receiving packets, to control its duty cycle. The solid state relay already can be switched. Once this is done, I can then have most of the controll logic in a simple .NET app. Lessons learned (and applied) in this build:
  • Voltage reference is on board.
  • Hooked up all pins properly, for example, RB2 for the interrupt.
  • Properly managed the 5V and 3.3V portions of the board with no ground loops.
  • Checked all pins before plugging in expensive part.
  • I screwed up the TC amp again, but I use SPICE to design a new Layout, which is now on a tiny dauther board, preventing another pcb.
  • I bought at least two of each required part. this came in handy.
  • I had stocked up on basic opmps and a wide variety of resistors/caps/etc Prior to the build, this too came in handy.
  • I discovered that opamps have an input offset voltage. The TLC272 ended up having about 1.1mV. Which ends up being quite a few degrees C if I didn't compensate for this in the software. Ill have to watch out for this in the future.
  • Grounding as much of the copper as I can seems to help tremendously. This board has yet to crash or reboot. (cross fingers)
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