The aim of the project is to design and produce a compact, low-power sensors array that will be able to sense the air quality and the Heartbeat of the test subject. The collected information is to be transmitted to a server via long range communication protocol for further research and analysis.
The system consists of: Microcontroller – ESP32, 2 air pollution sensors – PMS5003 & SGP30, heartbeat detector – MAX30102, communication module – LORA and Power management block.
At predefined periods the system turns on, the Data is collected, packed and transmitted to cloud server (TTN – The things network) using LoraWAN protocol. Once the measurements completed the system enters sleep mode in order to save power.
The power management block has few roles: (1) charge and discharge the battery, (2) provides 3 different DC voltage to the system components {1.8V,3.3V,5V} and (3) cut the power when the device on sleep mode.
The subject is informed by a led indicator on the state of the system {Active, Sleep, BPM reading, pollution measurements}
All the components in the design were chosen based on size, price and power consumption resulting in low power, cheap and small PCB.
Overall the system is small, easy to use, with operation time over 1 day.
