The HPMA115S0-XXX is an Air Quality Sensor from Honeywell. It is designed to detect particulate matter (air borne particles like dust or smoke) in the environment. It features an optical sensing technology that provides high accuracy and fast response time, and is housed in an IP67-rated enclosure for protection against dust, water and other environmental elements. The unit also includes various digital outputs, including a UART interface to send data to a host controller, and digital I/O pins for connection to external devices.