Make: Volume 78

other components and requires through-hole

soldering.After assembly, this handheld device

has the SCD30 conveniently stacked on the

board, as shown in Figure

N

and on page 24. An

optional acrylic case diffuses the green, yellow,

and red LEDs so they’re visible across the room.

 OPTION 3: Compact and Small CO

2

Devices

You can build a compact CO

2

monitor based on an

Adafruit Feather microcontroller with the sensor

stacked on top, mounted on a FeatherWing

board.Guido developed a FeatherWing board with

either the two-channel SCD30 (Figure

O

) or the

one-channel MHZ-19 CO

2

sensors.You can also,

as in Option 4, buy equivalent components from

Adafruit, ...