This repository contains code for a cheap air quality monitoring station based on Nova Fitness SDS011 PM2.5 sensor.
The c directory contains code for the KDB+ extension library (written in C) that reads the SDS011 data from a device path (typically /dev/ttyUSB0) and sends that to the KDB+ side. KDB+ is a database specialized for time series made by Kx Systems. I use that database in the project as KX made a Raspberry Pi version of KDB+ available for non-commercial use. The sds.c file in that directory does not contain any KDB+ - specific code. This file can be useful for an SDS011 project that does not use KDB+.
The q directory contains the configuration and q code for the Enterprise Components system that manages KDB+ database processes and tables and uploads the data to the hosting service. Enterprise Components is an open source middleware for KDB+.