ESP32 Measurements over LAN

This project showcases a simple proof of concept using the ESP32 to collect temperature and humidity data and have it sent to a database using local area network (LAN). Its objective was to instrumentalize data collection by integrating embedded Arduino code with centralized server-side applications.

The same minimal setup and concept can be abstracted in order to incorporate sensor data ingestion as a module of larger projects.

Source Code

flowchart LR

subgraph containers["Compose Application"]
	API
	DB
end

d1["ESP32
(Device)"] -->|"Raw Data
(JSON)"| API["REST API
(FastAPI)"]
API -->|"Formatted INSERT SQL Query"| DB["Database
(Postgres)"]

ESP32 Embedded Code: Establishes a connection to the specified Wi-Fi network and synchronizes the device’s clock using NTP. Written in the Arduino language, this code then interacts with the DHT11 sensor to collect temperature and humidity readings. It packages the sensor data along with essential metadata - such as the device ID and the data collection timestamp - into a JSON object transmitted as payload over the network to the API sensor_observations endpoint.
API: Handles POST and GET requests directed to the sensor_observations endpoint. It processes JSON payloads sent by ESP32 devices, transforming them with pydantic into formatted SQL queries. These queries are then inserted into a PostgreSQL database using pg8000.
Database: A PostgreSQL database preconfigured to store humidity and temperature measurements sent by ESP32 devices. The primary operation involves the initial setup, such as creating the database schema, which is executed once when the container is initialized.