Node-RED_Install and Use

Version 39.1 by Herong Lu on 2022/07/26 09:07

Table of Contents：

1. Installation
- 1.1 Install Example for CENTOS
  - 1.1.1 Installation
  - 1.1.2 If you want to start Node-RED as a background process
- 1.2 Install in Dragino Gataway
2. Use Node-RED
3. Input Flow

1. Installation

Check installation instruction for different OS from this link: https://nodered.org/docs/getting-started/

1.1 Install Example for CENTOS

1.1.1 Installation

Reference Instruction from this link: https://github.com/node-red/linux-installers
Run below commands and wait for installation complete.

Verify if the installation was successful

Type in the command line interface node-red

The following information appears to prove that the installation has been successful

1.1.2 If you want to start Node-RED as a background process

Type in the command line interface nohup node-red &

It will prompt after startup

After seeing the above information, press enter

Type in the command line exit

The above is the installation and startup process of nodered. If you don't understand anything, you can go to the nodered official website. There are installation instructions for various systems. The address has a link at the top

1.2 Install in Dragino Gataway

Dragino Gateway is already installed, no need for users to install it by themselves

2. Use Node-RED

2.1 Login to Node-RED interface

Enter your public IP address followed by the port number 1880

example：http://xxx.xx.xx.xx:1880/

2.2 Add flow

Take NBSN95 mod1 UDP protocol as an example

After logging into the interface click "+" to create a flow

Rename the stream

Drag UDP into the editing area

The same method as above, drag and drop functions and debug into the editing area

configure UDP in

Write to the UDP port that the device node sends to the server

Example My UDP device node sends to server port 8585
just write 8585

Note: that the port that is already in use cannot be used. If the receiving fails, you need to check whether the port of the server is occupied. The sending port of the device node should not use the default port used by the server, such as a common port such as 8080.

In order to avoid data confusion, different types of nodes do not use the same UDP port, because different nodes have different data formats and different functions.

When the node successfully sends data, the effect shown in the following figure will appear

2.2.1 About function

If you are familiar with JS code, you can write it yourself
If you are not familiar, we have the JS code for each type of node, you just need to copy and paste it into it

2.3 Plot Chart for sensors

If you need data visualization, please refer to the following

1. Click Install
2. Search the dashboard
3. Click Install

After the installation is successful, nodered will show the following node icon

2.3.1 the line chart as an example

Drag the line chart to the editing area

Just drag and drop as many as you need, or you can copy

The demo uses 3 kinds. Voltage, temperature, humidity

double click function

Adjusted to 3, because we need to display 3 charts

2.3.2 the chart settings

Double-click while setting up the node as above

After the display interface is defined for the first time, subsequent charts can directly select the display interface

Connect graph nodes to functions with lines

Click to deploy

Enter the server public IP + port 1880/ui

example：http://xxx.xx.xx.xx:1880/ui

At this point, the basic demonstration of nodered is completed. If you need to beautify the chart and various visualizations, you can go to the official documentation of nodered for further understanding.