The Treehouse Blog

No structure here… just some random goings-on:

For the last several kernel updates for FC4, my DVD sharing using GNBD hasn’t worked. I guess those special ioctl()s aren’t getting translated over or something. And NFS or SMB sharing an encrypted DVD just doesn’t do anything good at all (ignoring the fact that NFS seems really sucky with the latest FC4 updates). So, after months of not being able to watch DVDs, I gave up, and bought a USB drive cage to attach a DVD drive to Oak. Works perfectly. Despite performance issues and cabling evilness, I still can’t completely rule out a stack of USB drives RAIDed as a bulk storage solution, especially with all of the device mapper coolness in Linux. Too early to be thinking of that, though, as the computer storage fund hasn’t matured yet, despite the fact that Oak is at 99% capacity.

As Doug has mentioned, Asterisk and VoIP is still pretty neat. I’ve setup a teliax account, since they have pricing like nufone with a whole lot of rate centers worth of DIDs (they’re essentially a Level3 reseller). So, we just need to get some VPN’ing set up. I’m in desperate need of some UT, and I think VPN might be a useful substitute for a LAN party this winter.

My grandfather (on my Dad’s side) has been in the hospital on and off for more than a month now. Currently he has pneumonia, is very weak, and not entirely coherent. Your prayers would be appreciated for what could be a difficult Christmas season for the family.

Things at Ship are going fairly well. I did shoot myself in the foot with the “ip arp inspection” feature of the Sup720 this week though. Does 15 pps of ARP traffic seem like a good default threshold for shutting down trunk ports to you? Me neither. Of course, I asked that question after two ports had been err-disabled. Hopefully Tim and I will get to do a real test of some VMPS soon, too.

This week I have been playing with my new PRO-2052 scanner. I bought this model because it has an RS-232 interface that can be used to control it. There is a free piece of software, sctl, that allows you to use it in Linux. I have had to tweak the code a bit for my purposes. I needed line buffering enabled to interface sctl with a PHP script, and also had to change the interfacing to make the ‘sreport’ function work with my model. I’ll probably post a patch at some point. So far, I’ve written a few cheesy scripts to log radio transmissions into a database and play them back. It’s not quite perfect, but it is doing what I want. It would be nice if this guy would release his source. I’d love to have the two-tone pager decoder that he has.

I’ve also been poking around various scanning sites. It looks like there still isn’t any progress decoding the OpenSky system used by the state of PA. Apparently it’s VoIP based. I also found a site with audio samples of various digital transmission modes. Many of the sounds are familiar from old movies and such. I think the PSK-31 sound is sortof like the bridge ambient sound from Star Trek TOS. Also found a great PDF with lots of communications tone tables, for Motorola Quick Call and others.

One of the things I wanted to take care of this summer was some type of outdoor lighting to be used when coming home at night. There just isn’t enough ambient light to figure out how to insert the key into the lock. I was considering LED lighting built into the deck, outdoor lights around the deck, and automating the existing outdoor lighting. Seeing this as an opportunity to finally begin playing with X10, I dove in.

The first phase was to control the deck and garage outside lights with a wireless remote. I purchased some X10 light dimmer switches to replace the light switches, a wireless transceiver, and a remote control. Everything worked well except the remote range seems a bit short. Latency wasn’t bad… probably a little less than a second.

Phase two involves the hall light, and a computer interface. I bought a PowerLinc USB and downloaded the WISH / x10dev software. The only “gotcha” for the software was that it assumes your hiddev0 is in /dev/usb whereas mine was in /dev. The error messages were not at all helpful in figuring that out, unfortunately. At this point the interface worked, but I had some phase issues: my two lights were on one phase, and the computer interface was on the other. Instead of building or buying a phase coupler, I went with Doug‘s suggestion of moving breakers around instead. They’re really about the easiest plug-and-play devices in existance, but it was something that I had never done before, so I certainly turned off the mains. My current unresolved issue is that the latency between issuing a command on the computer, and the device receiving the command, is aboud three seconds… way too long, especially if you want to do about six commands for a single event. Still haven’t figured out if this is as fast as the interface goes, or if there is a software bottleneck.

So, there’s my X10 project summary. I’m pretty happy with the results so far. It’s not incredibly cheap (I’ve spent about $100 to control three lights… albeit with a wireless remote and computer interface), but it has achieved the goal, and now I know a bit about X10 🙂

Since Oak has never had a DVD drive, and likely never will, I haven’t been able to play DVDs using MythTV. Unlike TV cards, MythTV has no means of sharing DVD drives between machines. Using GNBD (thanks to its inclusion in FC4) has given me the ability. GNBD works perfectly as advertised, however since the means of reading CSS keys from DVDs is apparently odd (ie, it generates errors), that part would not complete. For some reason, running mplayer on the machine with the DVD drive caches the data (apparently) allowing the remote mplayer to then play without difficulty. I demonstrated the process last night, and I scripted it tonight… ready to watch DVDs now! I had been going through Nemesis-decompression-scene withdrawal.

I’ve added the first WAN link to the thtech network: 802.11g to Chris‘s house. We used garden hose as conduit for about 250’ of CAT5e from my shed to the WAP. The WAP was mounted on a pole inside of a tupperware container. Ethernet handled the distance fine, but a trivial POE implementation arrived at by splicing the power adapter that came with the WAP into the CAT5 didn’t work. There was too much resistance on the line for the 5v power to overcome. So, we tried stepping up to 12v with a DC-DC converter on the other end. This would result in the WAP partially powering up, but continually rebooting. I figured that this was due to the WAP drawing too much power when it tried to power up the radio. I purchased a higher capacity DC-DC converter at WalMart, and all has been well. We’re currently getting 600 KB/s, but earlier tests had us at about 1.1MB/s. We’ll have to do some antenna tweaking to try to remedy that.