Make: Volume 82

4. CONNECT SENSORS TO METRO THROUGH

BFREE

Now let’s set up the weather station. Follow the

wiring diagram (Figure

C

) to connect the Si7021

temperature and humidity sensor module (black)

and the RFM9x LoRa transceiver (blue) to your

BFree shield on top of the Metro M0.

Before running your weather station from

the solar panel, let’s test that everything works

on constant power. Connect the Metro to

your computer, and upload the Battery Free

Transmitter code from the Weather Station

repo. This new main.py program accumulates

temperature and humidity samples, averages

them, and sends them as a LoRa packet in a

continuous, non-breakable loop.

Now