Node-RED Charts of Historical Sensor Data¶

Lab Objectives¶

In this lab you will read the historical sensor data from a Cloud storage database and create a graph of prior readings. You will learn:

How to read datasets from a Cloudant database
How to create a chart of historical data

Introduction¶

The previous section stored the Device environment sensor data into a Cloudant DB. This section will read the historical sensor data from a Cloud storage database and create a graph of prior readings.

Step 1 - Import the Node-RED Historian Chart Flow¶

Open the “Get the Code” github URL listed below, mark or Ctrl-A to select all of the text, and copy the text for the flow to your Clipboard. Recall from a previous section, click on the Node-RED Menu, then Import, then Clipboard. Paste the text of the flow into the Import nodes dialog and press the red Import button.

Node-RED Historian Chart Flow : Get the Code

Click on the Cloudant node on the Historical Chart flow to confirm that it is configured to your IoT Platform Cloudant service instance.
Click the Deploy button on the top of menu bar to deploy the Node-RED flow.

Step 2 - Graph Historical IoT Sensor data stored in a database using Node-RED¶

The Historical Chart flow reads the IoT Sensor Device data from the Cloudant database and formats it into a Chart array before sending the data to a Node-RED Chart node.

Node-RED Historian Flow

Step 3 - Historian Charts of Device Environmental Sensor data¶

Turn to the Node-RED Dashboard browser tab, click on the menu tab in the upper left corner, and select the Historical Data tab.
On the Historical Data dashboard, click on the LOAD ESP8266 DHT DATA button to start the data visualization.
The button will trigger the read of the historian DB records created in the previous section.
In the Create a Chart Array for Chart.js function node the time series temperature data from the Device Environmental sensor is formatted into a Chart Array and sorted chronologically.
The Chart Array is passed to the Node-RED Chart node to render the graph.

Node-RED Historian Flow