Temperature & Humidity Monitoring on Raspbian using DHT Sensors

Overview

This solution comprises four main components:

• The following three components are running in Docker containers:

  • Agent: A Python script that scrapes data from temperature and humidity sensors.
  • API: A .NET Core API.
  • MongoDB: The database.

• Desktop Client: A WPF application presenting temperature and humidity data. Requires .NET Core 6.0 runtime.

• Mobile Client: A MAUI app, still in development.

Supported Sensors

This solution is compatible with the following sensors:

• DHT11: Tested but not recommended due to imprecise humidity readings (off by 20-25%).
• DHT22

Requirements

To implement this solution, you will need:

• Raspberry Pi: (Tested on Pi3 & Zero; one hosts API, Agent, and DB, and the other hosts only Agent).
• DHT 22 Sensors: Available for purchase on eBay for approximately £3 each.

Setup

The easiest way to set up this solution is as follows:

1. Connect DHT Sensor to Raspberry Pi GPIO:

   • Power pins 2 & 6 and signal pin into pin 11 (GPIO17, configurable when running the Agent's Docker container).

2. Install Docker.

3. Run Docker Compose:

   • Execute 'docker-compose -f docker-compose.yml up'. This will spin up the API, Agent, and DB.

4. Monitoring Multiple Rooms:

   • If monitoring multiple rooms (using additional Raspberry Pi's with DHT sensors), run another Agent and connect it to send data to the API. For example:

   docker run --privileged -e API_URL={API_IP}:80 -e ROOM_NAME=demo_room -e SENSOR_MODEL=22 -e GPIO_PIN=17 -e INTERVAL_SEC=60 mcopjan/raspberry-hum-temp-agent:latest
   

Demo