
orders.The sensors are now back in stock but
it caused Guido to start designing for different
sensors in case he had to find replacements.
HARDWARE
At the core of a CO
2
monitor is a microcontroller
that connects to the sensor and a display.The
basic microcontroller in our examples is the
ESP8266. Powering the board and logging data
are additional considerations; Options 1–3 listed
here are powered by USB, Option 4 by battery.
The individual components are not expensive
but generally add up to $100–$200. You can find
the complete parts lists for all these options at
makezine.com/go/co2-monitor.
One reason to look at these different options
is ...