Make: Volume 78

an appropriate emoji with a single word, along

with a color and the ppm reading (Figure

I

). He

used the Adafruit Matrix Portal that provides a

plug and play option with an onboard M4-based

microcontroller.

The Elements of a CO

2

Monitor

A CO

2

monitoring device has all the elements

of an Internet of Things application: hardware,

software, and data.That’s a big reason Guido

wanted to develop a kit for students to build a

device and use it in their schools (Figure

J

).

“The kit that the pupils are building these days

is easy to build,” he said.“It has a tons of options

and it gives us a lot of flexibility.”He encourages

the kids to create differ ...