Seamless Wireless Sensor Monitoring: From Field to Web with Node-RED and Raspberry Pi

In a previous article, we explored how to display real-time sensor data on a webpage using Node-RED, focusing on USB-connected sensors. Now, we'll delve into the exciting realm of wireless sensor networks. At EnviTronics Lab (formerly DurUntash Lab), we've developed a streamlined approach to collect and visualize data from wireless sensors, enabling you to build your own private monitoring system without recurring subscription fees.

Building Your Own Private Wireless Sensor Network

Imagine monitoring soil moisture in your garden, greenhouse, or grow room with a custom-built, cost-effective wireless network. It’s not only feasible but also incredibly rewarding. Our system leverages a star topology, combining long-range wireless nodes, sensors, a gateway, and a user-friendly computer interface.

We offer two types of wireless sensor nodes:

• ISHTAR 1P-LR: Single-channel nodes for individual sensor readings.

• SHINAK 4P-LR: Four-channel nodes for simultaneous data collection from multiple sensors.

You can mix and match these nodes to suit your specific needs, with a network capacity of up to 100 sensor channels. Data is aggregated by our ISHKUR G-WF gateway, which acts as the central hub of your network. A minimum of one sensor node and one gateway are required to establish a functional network.

The gateway, designed as a “dumb gateway”, connects to a PC or Raspberry Pi via WiFi or USB, simply relaying the raw sensor data. We’ve developed the SHUSHAN CVI-Wireless Windows application to parse, record, and visualize this data. Sensor readings are transmitted as comma-separated value (CSV) strings, with the gateway appending signal strength and its own identifier before transmission.

All DurUntash Lab wireless sensor nodes are designed for ease of use. They automatically detect sensor types (specifically DurUntash sensors), acquire readings, perform signal conditioning (calibration and temperature compensation), and format the data as CSV strings, accessible via their USB ports. This eliminates complex configuration, allowing you to simply connect your sensors and gateway.

For those unfamiliar with CSV data strings, the ISHTAR Zero sensor adapter’s user manual provides a detailed explanation of our communication protocol, which is consistent across our wireless sensor nodes.

The ISHKUR gateway effectively functions as a multi-sensor adapter. It offers USB connectivity for direct connection to a Raspberry Pi and potential WiFi connectivity, although this requires advanced knowledge of the communication protocol.

Visualizing Wireless Sensor Data on a Webpage with Node-RED

Having established our wireless sensor network, we can now focus on visualizing the collected data. The DurUntash Lab system provides formatted sensor data via USB, which can be processed using either our SHUSHAN Windows application or, for a more hands-on approach, Node-RED.

Leveraging Node-RED for this task is similar to processing data from USB sensor adapters. In a previous post (see "Real-Time Monitoring of Data from Multiple Sensors on a Webpage using Node-RED"), we detailed how to create a Node-RED flow to display sensor data on a webpage. Rather than repeating that information, you are encouraged to refer to that article for a comprehensive guide to building your visualization dashboard.

By combining the wireless sensor network with Node-RED, you can create a powerful, customized, and subscription-free monitoring solution, bringing your sensor data to life on any web-enabled device.