Thingsboard is an open-source server-side platform that allows you to monitor and control IoT devices. It is free for both personal and commercial usage and you can deploy it anywhere. If this is your first experience with the platform we recommend to review what-is-thingsboard page and getting-started guide.
This sample application performs collection of temperature and humidity values produced by DHT22 sensor and further visualization on the real-time web dashboard. Collected data is pushed via MQTT to Thingsboard server for storage and visualization. The purpose of this application is to demonstrate Thingsboard data collection API and visualization capabilities.
The DHT22 sensor is connected to Raspberry Pi. Raspberry Pi offers a complete and self-contained Wi-Fi networking solution. Raspberry Pi push data to Thingsboard server via MQTT protocol by using paho mqtt python library. Data is visualized using built-in customizable dashboard. The application that is running on Raspberry Pi is written on python which is quite simple and easy to understand.
The video below demonstrates the final result of this tutorial.
Once you complete this sample/tutorial, you will see your sensor data on the following dashboard.
Resistor (between 4.7K and 10K)
2 female-to-female jumper wires
10 female-to-male jumper wires
3 male-to-male jumper wire
|DHT-22 Pin||Raspberry Pi Pin|
|DHT-22 Data||Raspberry Pi GPIO 4|
|DHT-22 VCC||Raspberry Pi 3.3V|
|DHT-22 GND (-)||Raspberry Pi GND|
Finally, place a resistor (between 4.7K and 10K) between pin number 1 and 2 of the DHT sensor.
The following picture summarizes the connections for this project:
Note Thingsboard configuration steps are necessary only in case of local Thingsboard installation. If you are using Live Demo instance all entities are pre-configured for your demo account. However, we recommend to review this steps because you will still need to get device access token to send requests to Thingsboard.
This step contains instructions that are necessary to connect your device to Thingsboard.
Open Thingsboard Web UI (http://localhost:8080) in browser and login as tenant administrator
Goto “Devices” section. Click “+” button and create device with name “DHT22 Demo Device”.
Once device created, open its details and click “Manage credentials”. Copy auto-generated access token from the “Access token” field. Please save this device token. It will be referred to later as $ACCESS_TOKEN.
Click “Copy Device ID” in device details to copy your device id to clipboard. Paste your device id to some place, this value will be used in further steps.
Following command will install MQTT Python library:
sudo pip install paho-mqtt
Install python-dev package:
sudo apt-get install python-dev
Downloading and install the Adafruit DHT library:
git clone https://github.com/adafruit/Adafruit_Python_DHT.git cd Adafruit_Python_DHT sudo python setup.py install
Our application consists of single python script that is well commented. You will need to modify THINGSBOARD_HOST constant to match your Thingsboard server installation IP address or hostname. Use “demo.thingsboard.io” if you are using live demo server.
This simple command will launch the application:
Finally, open Thingsboard Web UI. You can access this dashboard by logging in as a tenant administrator.
In case of local installation:
In case of live-demo server:
See live-demo page for more details how to get your account.
Go to “Devices” section and locate “DHT22 Demo Device”, open device details and switch to “Latest telemetry” tab. If all is configured correctly you should be able to see latest values of “temperature” and “humidity” in the table.
After, open “Dashboards” section then locate and open “DHT22: Temperature & Humidity Demo Dashboard”. As a result you will see two digital gauges and two time-series charts displaying temperature and humidity level (similar to dashboard image in the introduction).
Browse other samples or explore guides related to main Thingsboard features: