die on invalid data

[air-quality] / README

Experiments with air quality sensors

Scripts in this directory read from sesor serial port output (which
is 3.3V serial connected to usb serial dongle) and store data to
influxdb using curl.

When receiving data from sensors, they check  header and checksum to
avoid sending garbage data. This also helps when you select wrong
serial port, beacuse script from wrong sensor won't send invalid or
corrupt data. Timestamp are also generated locally to mitigate any
network latency to influxdb (which is somewhere in the cloud, and
latency can vary just enough to create empty vertical stripes in
graphs which is ugly and incorrect).