One week of sea level rise recorded by the Sea Leveler.
Now that most of the bugs are out of the system, here is what a one week readout looks like on the Sea Leveler.
A few observations:
- The Sea Leveler is driven by twitter’s own search API, which is not perfect. The rapid dramatic drops are due to twitter updating its search parameters to exclude tweets more than a week old. Thus, the Sea Leveler records increased activity in real time and decreased activity less frequently, but in larger steps.
- I didn’t line the paper up very well, so the dates and times aren’t perfectly calibrated.
- The massive drop on 9 April is slightly more than a week after Boing Boing picked up the Sea Leveler, thus reflecting the tweets resulting from the coverage being purged from the search.
- The vertical lines that drop and return quickly are errors in the search function. The Sea Leveler is programmed not to move if the search function returns 0 tweets (which would indicate a connectivity problem).
- I don’t know what was going on on 12 April, but @johnvanderhoef and @lindsaycthomas were tweeting up a storm from what sounds like a very interesting series of talks.
I’ve currently set the Sea Leveler to record a full month on one roll, so be sure to check back in May to see how it’s going. Until then, keep talking about #sealevelrise!
The Sea Leveler.
Two weeks ago, I announced my latest Hacking the Ocean project, an open-source, Arduino-powered water level meter that monitors the frequency of tweets containing the hashtag #sealevelrise. Since launch, the Sea Leveler has had some bugs and received some good press. Now that I’ve had some time to monitor its performance and work the bugs out of its code, it is finally time for the promised “how to build the Sea Leveler” post.
This project was much more involved than my Arduino build and significantly more rewarding. The Sea Leveler was a challenge on multiple fronts, from learning to make the Arduino talk to twitter to physically modifying the water level meter. As I noted in my first project log, I have very little programming experience, and the major goal of this build was to level up my C++ skills. I’m very happy with the results, both technical and aesthetic.
For simplicity, I’m going to break this into two posts, one for hardware and one for software.
Earlier this week I launched the Sea Leveler, and open-source, arduino-powered, water level meter that measure the activity of tweets about #sealevelrise on twitter. Not surprisingly, the first full week of trial revealed a few bugs in the machine.
Sea Leveler read-out. Click to embiggen.
The first thing you’ll notice is that, in addition to recording tweets about sea level rise, the Sea Leveler also provides a nice documentation of power surges. Every time the power flickers, the arduino resets and the arm thinks it’s back at zero, causing a dramatic rise. This happened once due to an actual power surge and twice due to our marvelous dishwasher, which happened to be on the same circuit as the Sea Leveler. Easy fixes, both.
The second problem is that, thanks to our very cheap step motor (you get what you pay for) after a few power cycles, the unit starts rotating in the opposite direction. Wonderful. Obviously the permanent fix is to get a slightly higher quality motor, but for now, isolating the circuit to reduce power surges will have to do.
The Sea Leveler, an open source, arduino-powered, water level gauge that measures activity on twitter.
Two weeks ago, a machine was left on the “free” table at my lab that surprised me–a beautiful stainless steel mechanical water level gauge, on of those old ones with a flywheel in the back that drives the mechanism. Seeing this made me realize that there must be thousands of old scientific devices rusting away in laboratories across the country, obsolete but too well-build to just be thrown out. Then, I thought, there must be some way to take these old tools, some of them elegant, hand crafted works of industrial art, and give them a second life. For Science Online Oceans, I proposed a section on “Hacking the Ocean” developing low-cost, DIY instrumentation to make oceanography accessible to a broader community, but could that work the other way? Can we harness that same maker mentality to take abandoned scientific instrumentation and turn them into tools for education and outreach, or create art through instrumentation?
So I built the Sea Leveler.
As I mentioned during the last Blue Pints episode, this year I’m going to be attempting to build a low-cost open source CTD for basic oceanographic measurements. This is in addition to my ongoing work with the OpenROV. I have a pretty solid electronics background, but in order to accomplish this goal, I also need to learn how to program microcontrollers, something that I’ve never done before. For the next several months I’m going to tackle various small Arduino project to get comfortable with the fundamentals. I’ll be working out of Environmental Monitoring with Arduino: Building Simple Devices to Collect Data About the World Around Us and Arduino Projects to Save the World, both of which feature beginner to advanced projects based around environmental monitoring and data collection, as well as Programming Arduino Getting Started with Sketches for as a basic programming primer.
For my first project, I wanted to start with something that could eventually be implemented with the OpenROV–a magnetometer to provide compass headings while navigating the robot. As a first step, I wanted to learn how to program the Arduino board to calculate compass headings from a magnetometer and develop some sort of rough visual readout of that heading.