60 lines
2.6 KiB
Markdown
60 lines
2.6 KiB
Markdown
# Node-RED
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If you boot up our tech stack using `docker-compose` you already have a Node-RED instance running on [your local machine](http://localhost:1880/).
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Node-RED is an open-source, low-code, visual programming tool based on the concept of flow-based development. The idea behind it is to make it very easy to connect APIs, hardware devices, and anything else accessible over some type of network connection.
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## Core Concepts
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Nodes are the important part of Node-Red. They are the building blocks when working with Node-Red. Nodes are triggered by either receiving a message object from a previous node or an external event like an MQTT event. The node processes the message or event and then passes it on to the next node.
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A node can:
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* Inject: Starts a flow by injecting a message or a payload.
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* Change: Here you can do basic transformation or modification on the message object.
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* Debug: Can be used to help developing flows by sending messages to the side bar.
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* Switch: Here you can add logic (like sending the message to different nodes).
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* Function: Add custom JavaScript for uses cases where simple nodes do not do the trick.
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Flows are an organized sequence of nodes. Let's do the "first steps" by creating a simple flow.
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## Plugins
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Node-RED uses plugins (e.g. for InfluxDB or own Dashboard capabilites).
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You can access the plugins in the right burger menu.
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## First steps
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For debuging you can add Node-RED's own dashboard (sure, we are going to use Grafana, later).
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The dashboard should be visible on the righmost menu item in Node-RED.
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In Node-RED you can add a MQQT node to receive values from the power monitor. As we run in `docker-compose`you don't have to use the IP address of our Eclipse Mosquitto sever, but you can simply use `mosquitto` as the host nome.
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git a
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To simply display the values in a gauge (or chart) you can hook it up to a gauge node.
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In the dasboard section you have to create a tab. Inside this tab you have to create a group.
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The tricky part is putting the gauges in the group. This is done in the gauge's settings (not in the dashboard's settings).
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You can view the dashboard in an (also mobile) web browser.
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Have a look at the flow also in [this repository](./00-dashboard-example/dashboard.json).
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You can also [connect to InfluxDB](./docs/node-influx.md). |