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 Arduino UNO. Arduino UNO connects to the WiFi network using ESP8266. Arduino UNO push data to Thingsboard server via MQTT protocol by using PubSubClient library for Arduino. Data is visualized using built-in customizable dashboard. The application that is running on Arduino UNO is written using Arduino SDK which is quite simple and easy to understand.
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
11 female-to-male jumper wires
3 male-to-male jumper wire
In the current tutorial WiFiEsp Arduino library is used to connect Arduino board to the internet. This library supports ESP SDK version 1.1.1 and above (AT version 0.25 and above). Please make sure that your ESP8266 has compatible firmware. You can download and flash AT25-SDK112 firmware which is tested in this tutorial.
Please note that serial baud rate of ESP8266 should be set to 9600 by the following AT command:
|Arduino UNO Pin||ESP8266 Pin|
|Arduino UNO 3.3V||ESP8266 VCC|
|Arduino UNO 3.3V||ESP8266 CH_PD|
|Arduino UNO GND||ESP8266 GND (-)|
|Arduino UNO D2||ESP8266 RX|
|Arduino UNO D3||ESP8266 TX|
|Arduino UNO Pin||DHT-22 Pin|
|Arduino UNO 5V||DHT-22 VCC|
|Arduino UNO GND||DHT-22 GND (-)|
|Arduino UNO D4||DHT-22 Data|
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 “Arduino UNO 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.
If you already familiar with basics of Arduino UNO programming using Arduino IDE you can skip the following step and proceed with step 2.
In order to start programming Arduino UNO device you will need Arduino IDE installed and all related software.
Download and install Arduino IDE.
To learn how to connect your Uno board to the computer and upload your first sketch please follow this guide.
Open Arduino IDE and go to Sketch -> Include Library -> Manage Libraries. Find and install the following libraries:
Note that this tutorial was tested with the following versions of the libraries:
Download and open arduino-dht-esp8266-mqtt.ino sketch.
Note You need to edit following constants and variables in the sketch:
Connect your Arduino UNO device via USB cable and select “Arduino/Genuino Uno” port in Arduino IDE. Compile and Upload your sketch to device using “Upload” button.
After application will be uploaded and started it will try to connect to Thingsboard node using mqtt client and upload “temperature” and “humidity” timeseries data once per second.
When application is running you can select “Arduino/Genuino Uno” port in Arduino IDE and open “Serial Monitor” in order to view debug information produced by serial output.
Finally, open Thingsboard Web UI. You can access this dashboard by logging in as a tenant administrator. Use
in case of local Thingsboard installation.
Go to “Devices” section and locate “Arduino UNO 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 “Arduino DHT22: Temperature & Humidity Demo Dashboard”. As a result you will see two time-series charts and two digital gauges displaying temperature and humidity level (similar to dashboard image in the introduction).
Browse other samples or explore guides related to main Thingsboard features: