Reza’s Rants

For some reason, I was no longer able to connect to southwest’s website from my Vista machine, though I could reach it without a problem from my other linux boxes.  Now, I’m somewhat technical savvy, but it was quite a challenge to find the problem and come up with a solution.

First, the problem: I could no longer browse http://www.southwest.com/ from my vista machine.  It worked from my unix boxes.  I investigated a number of roblems ranging from viruses on my box to a corrupted hosts table.  Nothing worked.  Odder still, southwest.com is DNS round robin’ed to two different IP - and I experienced the same thing on both IPs.

The solution:  After trying a lot of things over multiple days, I managed to install tcpdump on my linksys router (running DD-WRT).  I noticed a small diference in the packets going from my vista machine and from my linux box. 

01:14:39.667122 IP 76-191-215-90.dsl.dynamic.sonic.net.49913 > www.southwest.com.www: SWE 212965372:212965372(0) win 8192
01:14:42.665436 IP 76-191-215-90.dsl.dynamic.sonic.net.49913 > www.southwest.com.www: SWE 212965372:212965372(0) win 8192


01:14:50.994221 IP 76-191-215-90.dsl.dynamic.sonic.net.40063 > www.southwest.com.www: S 3059118406:3059118406(0) win 5840
01:14:51.047515 IP www.southwest.com.www > 76-191-215-90.dsl.dynamic.sonic.net.40063: S 2964067491:2964067491(0) ack 3059118407 win 5792

The blue is the vista box and the red is the linux box.  If you notice, the vista box has flags ‘SWE’ set and the unix box only has the ‘S’ flag set.  I forwarded this to two of my smart friends, and one replied…

wtf? Those are some fucked up flags..

S = SYN ( that’s fine )
W = ECN CWR (Explicit Congestion Notification - Congestion Window Reduced)
E = ECN-Echo (telling the sender it received a CE packet)

wtf is Vista trying to do??

The ECN shit is all from RFC 3268… read up on it if you want… I don’t
know too much about it, sorry.

Fucking Microsoft needs to die in a fire, regardless.

So I googled Vista and ECN, and found a command to turn of ECN…

C:\Users\reza.slut>netsh interface tcp set global ecncapability=disabled

And sure enough, that command turned it off, and now I can go to http://southwest.com/ from my vista box.  My only question is — how is a layman supposed to be able to figure that out?  God, there are many people at microsoft that deserve to be shot.

I’m very excited; the latest version of the Berkeley Tricorder has been assembled, and is en route back here.  I’m expecting to get them in early next week.  Yay!

Oh my!  What a thrill to have the movie industry juggernaut actually release a good movie!!! It’s unheard of.  I drove home way too fast after watching the flick, got home, and started pacing back and forth… It took about 20 minutes before I could sit down.  I will be seeing it again in the next couple days.  And I must say that they did such a great job casting the characters.

I will add that one of the reasons I loved the movie was that it was internally totally logically consistent.  I hate how movies try to pretend that they are somewhat realistic by throwing some refernces to real technologies, then utilizing that technology in an unrealisitic way.  Please, why not start out with a ficticious but internally consistent technology, then utilize that technolog as the author sees fit.

The only problem now is trying to figure out how to go to sleep after that rush.

A long time in the works, but this version adds full pulse oximetry support, includes a mini-B usb connector for interfacing and battery charging, and a lot of RF filtering to help make the ECG signal more stable in noisy environments.     

EDIT: Forgot to mention, we’re also switching to the LIS302DL accelerometer, same one as in the iPhone, and we’ve switched our reference voltage amp to the AD8644 to help with the SP02 stuff.  The new design frees up some A2Ds which we’re using to monitor battery voltage and bringing out the other unused channels to the big connector on the bottom.

I actually had a great time and talked to lots of interesting people at the ESC conference.  I did notice two trends that seemed prevalent — not that they have much to do with my project, but that I still found interesting.

First, the massive interest in capacitative touch sensors.  It seems as if a number of big players from Silicon Laboratories, Atmel, Cypress, etc. are really promoting their touch sensor products.  Atmel bought Qmatrix which was the original player in this space, and it seems as if other vendors developed their own tech.  I didn’t see much of the guts of the Silicon Labs product, but I did get a demo board of the Ateml product.  It doesn’t work very well.  The Cypress guys seemed to have a neat product — it seems as if they’ve incorporated FPGA-like logical blocks that you can configure on the fly — as well as assign any pin any function (or so it seemed).  Though I can’t really recommend them as they made me sit through a 10 minute long speal which was really 20 minutes long - was boring and conveyed no information for the promise of a dev board to play with — only to walk away with a tshirt instead.  *Grumble*

The second big trend is in using 2.4Ghz transiever ICs for zigbee, zigbee variants, or for propriatary devices.  All the products seemed quite low power, small form facture, required a minimal of extneral components and promised quite a range.  Atmel’s new Raven product demos software developed by some company up in SF which lets you put an IP stack on one of Atmel’s transievers.  They were able to ‘ping’ a remote device which was really nice.  I like the idea of being able to telnet to my wireless peripherals.  The guy I talked to was an eecs major from Cal.

On other notes, they had some other interesting stuff going on.  They took apart a $2000 10″ OLED display to show the innards, but it was fairly boring.  Supposedly they took apart a space-suite the day before but I missed that.  They supposedly had beer, but it was all gone by the time I got there.  I played with some real oscilliscopes that made me drool with envy — seems doing real time decode of various serial protocols is the new big thing in that catagory.  Of honorable mention is a company that makes hardened memory that looks like physical keys, and a company playing this video on one of it’s demo boxes of an elephant painting.  I have no idea what they were selling, but was blown away by the video.  It make me seriously respect elephants.

Finally, I had a nice talk with the people at TI and they mentioned how Harvard, and Rice University came out with a nearly identicall device as the Tricorder we are working on.  Here’s a photo of the rice device.  It’s the same size if you exclude the antenna at the top of our device, has the same microcontroller, and uses the same instrumenation amplifier.  We started our project almost 2 years before we posted anything online — I’m not sure what the harvard groups device looks like, but I would imagine it to also be simmilar.  It makes me think of the quote by the inventor of PCR (who is a surf bum from my understanding).  He said something to the likes of his discovery was a natural consequence of several discoveries that preceded it.  I wonder if this device is just a function of the technology becoming mature. They did introudce a new processor that’s 2x faster, has more memory, and uses less power when it’s in a suspend mode.  Given that it’s pin for pin compatible with the processor we’re using, I hope to implement them on the next version (which I hope to get out this weekend).

I also went to a tasty Thai restaurant afterwards with Corpse and Taner.  Super tasty food.  I’m not telling you were as I dont like places getting popular; I find that popular restaurants get complacent and the food starts to suck.  Happened to Thep Phamon.

In an attempt to clean up my laundry room, I decided to put a bit more time into my hydroponics automation project (parts of which were scattered all over).  Talk about problem after problem.  First off, I forgot to put a reverse biased diode across a relay and blew my power supply (it always blows fuses, tired of fixing..).  Then one of the optoisolator darlingtons  (from sparkfun) didn’t work, so I had to swap in a non-darlington optoisolator I had and lower the value of the current limiting resistor to get it to work.   I put all this inside the bottom of the blue box, went to wire it to the 3-prong power socket, but not only ripped the solder pad off from where the wire attached to the board, but I also ripped off the relay pin.  So I swapped out that relay with a spare I had, put it all togehter, but it didn’t work.  Seemed there was a bad solder joint in there so I took it all apart, fixed, and put it back together.  What took about 6 hours should have been at most an hour… I need to get my mill operational so I can fab my own PCBs rather than messing with the project boards of crap from Radio Shack.

Anyhow, I feel like I’m past that hurdle, spend some more time with wiring and stuff, tweaked the firmware to add some functionality, and went to program it — but vista complained about the hub not having enough power or something.. So I got up to unplug the AVR Dragon, dripped over the USB cabe to my PCB which was attached via an SMD USB-A connector.  Rather than coming it of the plug, it ripped off all the pads… Here’s a photo of it…Notice the USB connector on the DB-25, and the ripped pads in the bottom center of the PCB..

I’m in LA right now waiting for my dad to come out of surgery. He decided to climb a ladder that was on poor footing, it slipped, his leg got stuck in a rung on the way down, and now he’s having a couple plates put in. It could have been worse. But more importantly, I want to point out how bad the car rental agency called Advantage was. It took longer to get the car from LAX than it did to fly here.

Anyhow, prognosis is good, and I expect to hear good news in a bit when he gets out.

[Update]  The surgery went well, though it was perhaps the worst break possible, according to the surgeon.  Yay. 

Thanks to a really good friend of my fathers, we spent a weekend building a deck in my backyard.  The process wasn’t so bad, and it really opens up the backyard.  Special thanks goes to Bill F. for helping me carry the ton of wood in a UHAUL from home depot.

The beer that I helped Patrick make came out excellent.  It’s a chocolate porter.  Rather than putting in chocolate liqueur as per the recipe, we used a cup of coco powder, which seemed to work great!

I am also working on automating my hydroponics setup, and wanted to mention my trial at using a 3.5″ floppy disk drive stepper motor to push a syringe.  After some time tweaking it, it turns out that it just doesn’t have enough torque.  The AVR STK500 just drives the pins in the right sequence, the breadboard contains a simple dual H-Bridge.  Email me if you want further details..

Finally, my HD DirecTV receiver (DCT210) died.  I left it unplugged  for a few months, and it caused the power supply to go bad.   When I plugged it back in, it would just cycle on and at a rate of a couple Hz.  I pulled the supply, and it’s busted (it should be a flat output, not the sawtooth pattern).   I found references to other people having this happen to them after leaving it unplugged for a period of time.  I can get a used one cheap so it’s really not worth the time to debug it, but if someone has an idea why it’s happening, I would love to hear it.  I’ve decided to upgrade to the HR20 anyhow, so it’ll be moot. 

Well, not the whole tree, but a bunch of the major branches…

I’m not sure what the opposite to a green thumb is, but whatever it is, that’s what I have. Any plant I touch seems to instantly die, and I’m tired of it. So I’ve built a hydroponics setup in my laundry room with the goal of full automation such that I can enjoy the plants, but they can be shielded from my thumb-of-death.

I’ve planted Basil, Holy Mint, Cayenne, Cilantro, and Lemon Cucumber — the Cayenne doesn’t seem to be doing anything, one of the Cilantro pods seems a dud, but otherwise, I see some green leaves already! (The cucumber seems to be growing the fastest)..

Now, there are a number of hydroponic setups, and the configuration I’m going with is a container that fills with water and empties based on a timer. The lights are currently always on (2×20W broad spectrum fluorescent bulbs) but they will be migrated to a timer as well with an 18h/6h on/off cycle. Every week or so your supposed to change the water, add nutrients, and modify the pH.

If you ask me, it’s still too much work. So I ordered a cheap pH probe from china off eBay, and built a simple amplifier circuit for it using spare parts. The circuit is pretty basic and I can post it if anyone is interested. I connected it to a board that I had made some time ago but was not being used and added an SHT75 temperature & humidity sensor I had. So far, it just spits out pH (uncalibrated), temperature and humidity readings via USB.

pH: 8.1 (1.44V)
Temp: 67.820 F
Humi: 61.493%

It’s got 10 “switches” built into it that I can use to control things — such as pumps, lights, valves, and stepper-motor controlled syringes that I will fill with nutrients and acid. I hope to get to the point where it will just run by itself, change it’s own water, and maintain whatever environmental parameters that it needs to.