https://github.com/mathcale/rpi-smart-thermometer

Smart thermometer that pushes readings from a DHT22 sensor plugged on an Raspberry Pi Zero via MQTT to a Nest.js server
https://github.com/mathcale/rpi-smart-thermometer

dht22 iot mqtt nestjs nodejs postgresql raspberry-pi smart-home

Last synced: about 5 hours ago
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Smart thermometer that pushes readings from a DHT22 sensor plugged on an Raspberry Pi Zero via MQTT to a Nest.js server

• Host: GitHub
• URL: https://github.com/mathcale/rpi-smart-thermometer
• Owner: mathcale
• Created: 2022-05-21T04:21:49.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2023-11-19T19:12:39.000Z (about 1 year ago)
• Last Synced: 2025-02-06T20:45:50.979Z (1 day ago)
• Topics: dht22, iot, mqtt, nestjs, nodejs, postgresql, raspberry-pi, smart-home
• Language: TypeScript
• Homepage:
• Size: 2.69 MB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        



  

  
RPi Smart Thermometer

  


    

  


## Architecture

![Architecture diagram](docs/rpi-smart-thermometer-architecture.drawio.png)

Every 30 minutes, a Node.js script reads the current temperature and humidity from the DHT22 sensor plugged to a Raspberry Pi Zero W via GPIO and then publishes this data via MQTT to the Mosquitto server.

On the server stack, a Nest.js microsservice listens to a specific topic on the Mosquitto server and, when there's a new message, it gets parsed, validated and stored on a PostgreSQL database. This stack is deployed with Docker Compose to my local Raspberry Pi 4 home server.

There's also a button that, when pressed, will fetch the latest reading from the Nest.js API and show it on the OLED display. After 20s, the display will turn off to avoid burn-in.

## Schematics

![Hardware schematics](docs/rpi-smart-thermometer-schematics.png)

## Tech

### Hardware

- Raspberry Pi Zero W

- DHT22 sensor

- OLED display

- Push button

- 1K resistor

### Software

- Node.js 16

- Typescript

- Nest.js

- Next.js

- Docker

- PostgreSQL

- Mosquitto