Alexa Baked in a Pi

You can put Alexa in a Raspberry Pi, and that is pretty cool.

Alexa is Amazon's intelligent agent, like Siri for your living room. Standing nearby, you speak to it with a question or a command, and it responds verbally.

Normally Alexa lives inside a $180 device called an Amazon Echo, or the new $50 Echo Dot. But Emily Withrow at Northwestern University's KnightLab told me it was possible to put the Alexa code inside a cheap Raspberry Pi hobby computer. And I happened to have an old Pi lying around.

So I gave it a whirl!

Tracking Harlem's Heat with Sensor Journalism

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How hot is a Harlem apartment?

We're trying to find out.

There are now DIY sensors in about 20 apartments, measuring the indoor heat and humidity -- in the middle of a heat wave.

It's the latest sensor journalism project from WNYC's Data News Team, in a collaboration with blog AdaptNY, community group WEACT and observation platform ISeeChange

And this week we worked with maker space HackManhattan, which hosted a soldering party to build more sensors.

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!

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.

Make Every Week: Heartbeat LEDs

Visualizing one’s heartbeat is just cool. I’ve been into the idea since I learned that signals sent by the Polar heart monitor straps joggers use can be detected with a cheap device.

I’ve made a heartbeat hoodie, which was a lot of fun. But in the end, a bright, flashing sweatshirt starts to annoy the people around you. Now I’m working toward a more wearable wearable, one that changes subtly as my heart beats faster or slower.

This week I took a step on the way to that wearable by getting three LEDs — blue, green and yellow — to light up according to my heart rate. A calm heartbeat and blue glows, a little faster and you get green and really fast lights the yellow one.

Make Every Week: Fish Tank Carbon Dioxide Generator

We have a moderately successful family fish tank: The fish seem to survive, the plants do not.

(Also we’re really good at growing algae, and may start feeding it to the children.)

With a coding problem, you Google it and get several excellent solutions. With a fish tank problem, you Google it and get several excellent solutions that contradict each other.

So the excellent solution we’ve chosen to make the plants happy is to add carbon dioxide to the tank. Plants need it, and one of my favorite in-store tanks uses it. So it's settled.

I thought I’d need to pick up a heavy tank of CO2, like when I rented a tank of helium.

Turns out you can coax yeast to make it for you. This Instructable describes how, and is what I used to make ours.

Make Every Week: Fitness Wristband

The same week we got details about the new Apple Watch, my Nike Fuelband died.

That got me thinking about what I really want — and don't want — on my wrist, and whether I could build something that fit my needs exactly.

So expect a few #MakeEveryWeek weeks devoted to iterations of a fitness watch. This is one of them.

My Fuelband had a clock, which I used for timing my midweek runs of about 20 minutes (don't judge). But I had to keep checking my wrist, and pressing a button in the band, to see if time was up.

I really wanted something to simply tell me when 20 minutes was up. So that's what I made.

Make Every Week: Selfies from Space

This is a snapshot of my town — taken yesterday.

It is crazy-amazing that I can get an image from space on my computer in damn-near real time.

The camera is Landsat 8, a U.S. Geological Survey satellite with a dozen sensors on it. I got an introduction to using satellite imagery at the NICAR 2015 Conference in Atlanta last week, so I thought I’d give it a whirl for this week’s #MakeEveryWeek.

I wondered if I could see from space the lovely thaw we had the past couple of days, with highs hitting near 60.