Here's the high-wire act in which I describe the West Virginia University sensor-journalism project with 20 slides that advance automatically every 15 seconds. This took place in a room of brilliant thinkers at Newsgeist 2015 earlier this month in Phoenix.
I stumbled on a fun, visceral way to show how Arduinos can sense and respond.
In preparation for a presentation at the Online News Association Conference in Los Angeles, I grabbed a Ping distance sensor I had in a bin. The Ping works like a bat — it emits an inaudible, high-frequency sound, and listens for the sound to bounce off an object. The round-trip time between ping and reflection reveals the distance.
Yesterday the Streamlab class put do-it-yourself water monitors into Gatorade bottles and anchored them in the Monongahela River near Morgantown, West Virginia. They’re now texting their data readings live.
We’re sensing conductivity, which is a good indicator of dissolved solids in the water, and temperature. The locations are: upstream of an industrial site, downstream of the same site and further downstream below the Morgantown lock and dam.
A summer of tinkering has culminated with a conductivity and temperature sensor that texts its data from inside a Gatorade bottle.
The plan is to submerge several of these along a stretch of the Monongahela River as part of a sensor-journalism class at West Virginia University. It’s a work in progress, but you can [see how things are going]. My job was to build a working conductivity sensor that would report its findings live. Here are the components and how I made it go.
Update: We actually deployed some of these sensors in a river!
About a month ago I built a texting temperature sensor, which had some energy-saving code I learned about. I wanted to see how many days it would last on one charge.
It's still running.
Capacitive sensing is how your phone’s touch screen works — basically detecting the natural charge in a person’s body on the screen.
I’ve seen Team Blinky friend Liza Stark play and build simple touch sensors using the same technique with Arduino, so this week I gave it a try.
My goal: Use a touch sensor instead of a button on the Monthly Mood Cube.
It turns out to be pretty easy.
That’s what I did this week, as my wanderings into wireless data collection continue: Post the temperature and humidity from my little experiment to a table at data.sparkfun.com.
Here are the steps as things stand now:
- The sensor reads the data (as in my original post).
- The Ardunio formats a message and texts it with a Fona (wiring details here, updated code here).
- Instead of texting to Twitter, it now texts to a phone number I bought at Twilio for $1/month.
- Twilio then relays that data to my project server in the Amazon cloud as an http “POST” (deets on setting up a cloud server here).
- My project server parses the text message, composes a URL with the data, and hits the Sparkfun open data system with that URL (code for that is here).
This all happens in just a few seconds, every 20 minutes.
In just a few weeks, a class of journalism students will be wading into West Virginia streams to deploy water sensors.
They’ll be sensing water conductivity over several weeks using a cool, Arduino-like board called Riffle.
But the crux of the system is a simple circuit I tried for the first time tonight.