Smart Meter is a temperature, humidity, barometric pressure and air quality measurement & logging platform.
The system has the following components:
- Sensor (WiFi connected device doing the measurements) and Firmware
- Frontend (Website to present the measurements to the user)
- Backend (Database containing the measurements)
The sensor connects via WiFi to the home network and broadcasts its measurements in a 15min interval via UDP subnet broadcasting. Measurements are taken every 5min by the Bosch BME680. The ESP32-C3 runs the firmware handling data acquisition and WiFi connectivity. The device is powered by 4 AA batteries and lasts for about 2.5 months on a single charge. Each device has a unique ID derived from its MAC address.
The firmware is built on Espressif's esp-rs.
| State | Charge | Avg. Current |
|---|---|---|
| Boot | 800mC | - |
| Measure | 83mC | - |
| Measure + Send | 279mC | - |
| Light Sleep | - | 0.47mA |
The frontend is hosted on a local server (e.g., a NAS) running the docker image. It uses the yew framework (web app with WebAssembly written in Rust) and communicates with the backend via its REST API.
The backend uses Diesel to interface with an SQL database (sqlite) and provides a REST API to clients (the frontend) allowing those to request measurements and manage sensors. The REST API (Actix framework) features the following routes:
- GET
/api/measurements/by_date: Returns all measurements of a given device between a start and end data - GET
/api/measurements/info: Return general information about measurements of a given device (e.g., the measurement period) - GET
/api/measurements/all: Returns all measurements of a given device, samples down the measurements not to exceed a certain amount - GET
/api/devices: Returns a list of all measurements - GET
/api/device_name: Returns the name of a device by ID - POST
/api/device_name: Sets the name of a device by ID
The backend listens to incoming packages on UDP port 8989 and picks up new device on their first broadcast.
Frontend and backend are bundled into a single docker image, making it very easy to deploy on all systems supporting containers.
Smart Meter is licensed under CC BY-NC 4.0