scruffy days

The shows get better and better every year. This one featured a slew of eco-minded projects: BioBronc, Solar Jewelry, Solar Time (pictured here with my parents ), BikeJus, Device Power Monitoring, Blue Phoenix, and the debut of Sustainable ITP - a showcase of student and faculty work in the program’s sustainable practices initiative.

Solar Time, a project with Gilad Lotan, is a meter displaying the total amount of energy in watts available from ITP’s 80-watt solar panel located on the Tisch building’s roof. Readings are retrieved via a wireless radio network and logged in a database.

Also in the show was Under The Level, with Catherine Colman, a mapping project of New Orleans’ post-Katrina destruction on the streets of New York. More details at underthelevel.org.

A simple metering interface to increase awareness of the solar energy available in relation to daily electricity consumption. [some documentation to date]

Finally, I’m gonna take a moment and blog something besides Xbee code and alternative energy. Ahhhh… Almost forgot Suzanne had gotten tix for This American Life’s live tour - the show was excellent. Actually, I didn’t really realize when we got these tickets that they were for the launch of the t.v. show. I was skeptical like most of their decision to test the waters outside of radio, but tonight’s show was evidence of how cautious they were in approaching the whole thing. They opened with an animation telling the story of how some elementary school kids got caught up in a trend of playing with fake cameras made from cardboard/toilet paper tubes. This was executed so well - a compelling use of visuals for storytelling, and such a good intro for the show’s transition to moving images.

It was amazing to see Ira Glass in the flesh, working his radio magic on stage, and being able to associate his voice with physical mannerisms. There was discussion with the show’s director about delivering the show in a completely different medium - how terrified they were of a “sucky show”, avoiding the reality show angle, and using carefully crafted cinematography. The clips they showed still carried that distinct TAL essence - I’m looking forward to it. All this plus awesome performances from Sarah Vowell, Jonathan Goldstein, Dan Savage and Mates of State.

1 9V battery (Duracell) lasts approximately 1 week. By increasing sleep time, battery life for 8th floor circuit should improve, hopefully significantly. Reset pin 5, take low by dipping wire to ground.

XCTU Settings:
SP setting: 214 (hex = 532/60 = 8 sec)
SP is for setting/reading sleep period for cyclic sleeping remotes. Max is 268 seconds. Since we want to sleep every min instead of 8 sec, 6000ms = 1770 hex as new value.

Hmmm. This change alone didn’t work…
Seems ST (Time before sleep) needs to be increased also. When testing with Processing script, no readings appeared. Was 30 (48ms), then tried 150 (336ms). But now, no chance to sleep.

Next, tested these new settings together:
ST 54
SP 1770
GT 54
Results: It works! Yay! Every minute, reading is sent through…

Just a quick update - ran Tom’s Processing code to check on the mesh network - yay! the battery is still alive. Reading coming in at 1PM today (38 degrees F, cloudy) is 582, so we divide that value by 44.22 to get voltage reading of 13.16, which Gilad confirmed with a multimeter reading off the 12th floor controller. Here’s a screenshot:

Gilad and I continued working on RoofLink, a network of XBee radios for datalogging voltage readings from ITP’s solar panel. The problem we ran into last semester was keeping a steady supply of power to the XBee circuit on the 8th floor. For reference, here’s the original diagram again. But now, with the firmware upgrade to the radios, no PIC chips are necessary, and we’re powering the 12th floor circuit directly off the solar panel’s leads. This way, when the sun goes down, the circuit is turned “off” and the 8th floor XBee can get a good night’s sleep. Perfect, since there’s no data to log then anyway.

XBees consume 3.3V and 10mA (with no LEDs) in their “awake” operational state. With LED indicators for power, sending and receiving, they use 60mA.

MaxStream has a great app for configuring and testing the XBees, X-CTU, which you can download here (Windows only). This made adjusting the settings so much easier than when we were using Terminal/Screen and typing in AT Commands. That was much more tedious, and you’d only have a short window of time to enter new commands after the +++. Here’s a nice screenshot courtesy of Faludi. Also gives you details on commands and settings.

Tom guided us on using X-CTU’s handy features, and how to eliminate the PICs. Here are most of the settings:

Under ‘Modem Configuration’, select Always Update Firmware and Version 10A2.

#0 (12th Floor)
MY 0
DL 1
IR 17 (Sample rate)
IU 1
IT 5

#1 (8th Floor)
MY 1
DL 2
SM 4 (Cyclic sleep mode)
SP 214 (Cyclic sleep period)
ST 30 (Time before sleep)
GT 40 (Guard time)
DP 3E8
IU 1
IT 1

#2 (4th Floor)
MY 2
Will note other settings soon…

During testing, we used a DC Bench Power Supply to act as the solar panel. Got a Processing reading of 446 when feeding circuit 10V, but we’ll test other values to get the most accurate translation for datalogging.

Notes on Sleepy Time:
We tried a few approaches in sleeping the 8th Floor XBee. With Sleep Mode 5? (gotta double check this), we couldn’t wake the sucker up - had to manually reset the radio and exit out of that mode. Then we also tried this example from MaxStream, requiring a Coordinator/Remote relationship, but this wasn’t successful for us either. Eventually, it appeared to be a balance of timing between #0’s IR and #1’s SP and ST settings, with #1 set to Cyclic Sleep Mode. If #0 sent samples too fast, #1 would never have a chance to sleep; but on the other hand, if too slow, #1 wouldn’t catch any packets and keep returning to sleep. With current settings, readings come through every 15-16 seconds.

Amperage Measurements:
XBee #0
regular 6.0 mA
no LEDs 10mA
XBee #1
Cyclic sleep 24.5mA
Cyclic sleep, no LEDs 0.17 mA, with 2.16mA “burst” during sending of data

XPort Notes:
For the XPort on the 4th Floor circuit, updated Connect Mode from D4 to C4 (need to note why here). This was done just by telneting into the XPort’s IP address via Terminal and using port 9999. No need to do any of that hardware setup like when you initially configured these - takes you direct into Setup.

TO DO:

1. Review incoming values and adjust code
2. Update PHP script for datalogging, add Cron Job
3. Measure 9V battery life (new battery placed around 1:30am 1/31/07)

#0 - 12th Floor Circuit. Using Sparkfun FT232 for configuration

Setup with DC Bench Power Supply, and testing packet sending with Processing app from Tom Igoe

#0 - 12th Floor Circuit, with “resistor tree” enclosed in shrinkwrap tubing (just to have less exposed components)

#1 - 8th Floor Circuit. When sleeping, the green LEDs blip periodically. Yellow LED indicates both sleep and receiving of data.

Screenshot of data parsing using Tom’s PHP socky script, with some javascript data viz from David Nolen. Clearly, we’ve still got some tweaking of our readings to take care of. To be continued…

The theme of sensing visitors’ presence and colors is a topic a number of ITP projects touch on. The scale of it is visually interesting, but the response left us a bit disappointed. It wasn’t clear at first where you had to position yourself for the installation to react to your presence. We eventually saw the iSight, and even waved Tikva’s red jacket in front of it, but still the color shift was really subtle, and the faint pink hue slowly traveled up through the rest of the LED tiles.

But it made me think about why these types of pieces are still fascinating - we like to affect changes in our environment, and people are drawn to visually responsive/mirror like pieces. We like gadgets and technologies that DO things for us, respond to our touch, get info for us, tell us where we are, show a trace of where we’ve been… Danny Rozin’s mirrors and similar camera sensing/abstract mirroring projects are so appealing, I think, because you see yourself in another form, you affect change in this particular piece, and for a moment you are the main focus and actor in this piece. You actively become part of the project itself. What was missing from this installation seemed to be how limited where you had to be in order to become part of this experience. It would’ve been more fun to see how my colors could meet/mesh/clash with someone else’s and what that could imply. But maybe it just wasn’t working properly when we visited, since these Gothamist pics depict an entirely different experience.

A work in progress, but now provides some organized documentation on the project - gardenelectric.com

Yay! We made it!

Garden Electric came together in the nick of time - phew! We ended up modifying the layout on day 2 to fix the issue of air traveling upstream. The synchronized action of the bellows stole the show from our precious plastic flowers. Good feedback, kids loved it and we never tired of the Garden’s quirky, hilarious performance.

So many brilliant projects - wish I could’ve seen them all. Check out ITP Vlog & rocketboom for additional coverage of the show’s goods.

it’s 2:53am.

“first rule of the show is you don’t talk about the show…”