Crabbing in the bay

December 22nd, 2008

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So I bought some crabbing nets last year and had a try at crabbing off the pacifica pier — we failed. Tried again this year, and failed. So I went out with my cousin one night to a pier off Crissy Field and we got a ton (ok, just 5), but they were like all over the nets. So we tried it again (with Patrick) and this time, we only caught 2 babies.

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It was too dark to figure out which ones were male/female/dungenous when I went with my cousin so we threw them all back. The ones I caught with patrick were too small (<4 inches) so we threw them back. But one of these days, I will catch me some crabs and feast. I really want to get involved with hunting, killing, and eating my own food - but to do so where the prey has a fighting chance (at inflicting injury to me). Like hunting wild boar with a knife. Not sure if I’ll ever do that, but it seems like a nice thought. Believe it or not, but a Mauri (dude in blue in the photo) told me how to kill a boar with a knife while I was backpacking through New Zealand in a small town called National Park. The only things in that town were a bar/restaurant (owner was a huge fan of Jagger), a climbing gym, and a gas station with an attached convinience store.

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They had just finished filiming TLOTR just before I got there (like a day). And if anyone is curious, the way you kill a boar is to stand still, wait for them to almost get you, jump out of their way (they can’t change direction quickly and will pass by). As they pass by, jump on their back, and stab them in this small spot on the back of their heads just at the base of the skull (which is tick enough to stop a small bullet), and stab them in the spine.

Personal , , , , ,

Something new is coming..

December 21st, 2008

Any guesses what this is?

Electronics

“Genuine Kangaroo Scrotum” — is it real?

December 20th, 2008

So a friend of mine just got back from australia with this gift. I wonder if it’s real. Any thoughts?

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Personal

Human trials proceed

December 20th, 2008

Sample Data

I’ve just finished the second week of human trials, and I’ve already learned a lot about device usability and some weaknesses which I want to incorporate into a newer version of the chest strap.  The data is quite fun to go through, and it looks better than I expected for an ambulatory device.  Here’s an excerpt from one of our subjects..

Electronics, HealthMonitor

Twitter Updates for 2008-11-04

November 4th, 2008
  • Voted yes on R: Rename SFs water treatment plant to the “George W. Bush Sewage Plant” #

Personal

Restoring photoalbum; greybox; velociraptor

November 1st, 2008

I’ve been heavily neglecting my photoalbum code, so I’m starting to do some cleanup as well as to add some Web 2.0 tidbits into the mix.  I’m going to be gutting it some more, removing multi-user support, cleaning the interface, and hopefully be able to start adding more content to the site shortly.

I did find greybox, a good “lightbox” script.. I would like a few small teaks, like the ability to click on the photo to go to the next one, and the ability to move the title bar from the top to just below the photograph.  I would also love for it to preload the next photo. Otherwise, it avoids the annoying resizing delay when your going from one photo to the next - which most lightbox scripts use - which I hate.

I also want to give a shout out to Richard Hesse who was insisting that a fast HD was key to a fast computer.  He was right.. I upgraded to the velociraptor 300G HD and it balzes.   Well worth the expensive sticker price.

Personal, Software , , ,

Tricorder human trials about to start

October 30th, 2008

It was a few years in the works, but the time is finally here — time to collect some real data from random test subjects.  We’re going to be collecting SpO2, ECG, EMG, BioImpedence (respiration), and 3-axis accelerometry at 256Hz.   The firmware seems fairly solid, and the signals all look really good.

Tricorder and related hardware

Tricorder and related hardware

By friday, we should have 24 hours worth of nice, clean, data.   Else, I’m going to have a busy haloween weekend.

Electronics, HealthMonitor ,

Tricorder v7 working great

October 27th, 2008

After dealing with a few ugly hurdles (mostly having to do with a horrible new serial module in the MSP430F2618), life is starting to look really good. The filesystem is working very nicley with a shared serial bus with the accelerometer (SPI) and the bioImpedence circuit (AD5933 impedence measurement IC; I2C). See how nicely they play together..

And even the SpO2 signal is finally looking really /really/ nice..

Though that data is from a transmissive sensor. We’re still investigating the efficacy of an upper arm reflective sensor, but I’m quite pleased given the complexity of the new device.


Electronics, HealthMonitor , , ,

Hacking Ademco BiDirectional Protocol

October 25th, 2008

I want to interface into my Ademco alarm system, and the easiest way to do it is to intercept serial commands from the RF recieve module to the main unit.  Here’s what a waveform looks like..

From the looks of it, the duration of each packet is the same, so each bit should represent the same unit of time.  The first three transitions are the same for all packets, and the third transition is 2.5 bits long, so I would assume that’s a preable.  The rest of the data are in multiples of 420us.  I wrote a script to decode packets, and here’s a dump of a random capture.  Each line represents one message, like the one above…

1000000001001010111010001111110110001110101010001101101010001
1000000001001000011010001010101011001101111011001110011010001
1111110110001111111111001101111110001111011110001111111111111
1100000000001110111000001011011010001001101011001011111011001
1000000001001101101010001010011011001010111010001110111011001
1000000001001010010111001111101011001101100011001010110011001
1000000001001001100010001001100010001111110110001101010110001
1000000001001111110110001100111010001011011010001101101010001
1000000001001010111010001111110110001110101010001101101010001
1000000001001000011010001010101011001101111011001110011010001

Next I get to try to find some sort of pattern to the above mess, and hopefully the data is not encrypted — which I doubt it would be.. If anyone has any ideas, please let me know!

Electronics , , ,

FINALLY - the MSP430×2xx new serial module sucks! Finally got I2C working.

October 20th, 2008

It took a solid 25+ hours of work, but I finally got the MSP430F2618 to talk to the AD5933 via I2C.  The TIs documentation sucks, their module sucks, and I’m angry.  But it works now.  A hit to those that might be stuck: The USCIABxTX_ISR() interrupt vector should be called the Master interrupt vector, and their USCIABxRX_ISR() interrupt vector should be the Slave interrupt vector.  In master mode, both the TX and RX interrupt enables results in the TX_ISR() vector being called.

Other issues include that the SDA line gets stuck latched low and will persist through a power cycle and a reprogramming.  You expicitley have to pull the line high in software to reset it.

A bunch of other issues later, I got it working..  I ended up picking up a new logic analyzer because of it’s improved interface than my USBee unit.  $150, and it ROCKS.  Joe makes them locally, and I recommend you pick one up for your toolbox.

data read from ad5933

data read from ad5933

Electronics