johnkeefe.net

Make Every Week: Message From a Bottle

A summer of tinkering has culminated with a conductivity and temperature sensor that texts its data from inside a Gatorade bottle.

The contraption consists of a Riffle, which is an Arduino-like board designed to fit through the mouth of a water bottle and a Fona cell-phone board. And a 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!

Whoa: Low-Power Texter Still Texting

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.

Make Every Week: Sensing Human Touch

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.

Make Every Week: Temp -> Text -> Table

Texting temperature data to Twitter is fun, but more useful is sending that information to a table.

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.

Make Every Week: JavaScript + Arduino

JavaScript is the code that drives bells and whistles you see on almost any web page.

This week I used it to drive lights and motors on a table. And it was surprisingly easy.

Make Every Week: Audible Water Sensor

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.

Make Every Week: Low-Power Temperature Texter

I got the temperature sensor working and I got the Arduino texter working, but I had trouble getting them to work together.

Until this week.

After jumping several hurdles, I now have a portable temperature-texter, which has been sensing and texting to Twitter for two days now.

Make Every Week: Arduino Texting

Texting is something I love playing with, and I’ve always wanted to make a sensor-bot that skipped the hassle of wifi by texting me its data.

So this week, I tried to make some progress on that by making a texting bot.

Make Every Week: Taking Temperature

Taking temperature readings with an Arduino seems pretty straightforward — generic thermistors are easy to wire up. But I wanted something a more precise, with actual temperature readings.

So I got this air temperature and humidity sensor, and this week I gave it a whirl.

Make Every Week: Circuit Boards, For Reals

I always considered circuit boards like this something you bought, not something you made.

Not any more.

I actually helped to make the board in the picture above. And it was awesome fun.

The board is designed to monitor the conductivity (and, possibly, contamination) of water in lakes and streams, with the wonderful feature that it fits through the mouth of a regular water bottle. It’s called Riffle and it is the brainchild of Don Blair, who’s working with Public Lab and the MIT Center for Civic Media. This week I had the honor of working with Don at MIT.