node-red-contrib-datacake 1.0.0

Node-RED nodes for Datacake: subscribe to and publish device measurements via the Datacake MQTT broker

npm install node-red-contrib-datacake

Datacake nodes for Node-RED

Datacake is a low-code IoT platform. These nodes connect Node-RED to the Datacake MQTT broker, so flows can react to device measurements in real time and write values back to devices. They are also used in Cake Red, the hosted and managed Node-RED offering of Datacake.

• datacake in receives the values of one device, or of all devices of a product.
• datacake out writes values to a device, one field or several fields per message.
• datacake-configuration holds the API token and workspace. All nodes of one account share a single MQTT connection.

Nodes show the device and field they are connected to, for example Cold Room 3 › Temperature, and their status shows the connection state and the last value.

Requirements

• Node-RED 3.1 or later
• Node.js 18 or later

Installation

In Node-RED, open Manage palette and install node-red-contrib-datacake, or run in your Node-RED user directory (usually ~/.node-red):

npm install node-red-contrib-datacake

Setup

1. Create an API token in Datacake: Account Settings → API Token, or better an API user with limited permissions (Members → API Users).
2. Add a datacake in or datacake out node, open it and add a new account. Paste the token and pick the workspace.
3. Pick the device (searchable) and the field.

The token is stored in the encrypted credentials of Node-RED, not in the flow file. The editor never talks to Datacake directly; it asks the Node-RED runtime, which uses the stored token.

Example flows are available in Node-RED under Import → Examples → node-red-contrib-datacake.

datacake in

Output message:

{
  payload: 4.2,                       // number, boolean or string
  topic: "dtck/cold-room/<device id>/TEMPERATURE",
  deviceId: "<device id>",
  productSlug: "cold-room",
  fieldName: "TEMPERATURE",
  datacake: {
    deviceId, deviceName: "Cold Room 3",
    productSlug, productName: "Cold Room Sensor",
    fieldName, fieldLabel: "Temperature", unit: "°C",
    topic
  }
}

Names, labels and units are looked up once per device and cached; if the Datacake API is not reachable the message is sent without them.

datacake out

With Several fields from msg.payload, send an object:

msg.payload = { TEMPERATURE: 21.5, HUMIDITY: 48 };

Every key is published as its own MQTT message to dtck-pub/<product>/<device>/<FIELD>. Keys that are not fields of the device are skipped with a warning; temperature is matched to TEMPERATURE.

When device or field come from the message, a message that comes straight from a datacake in node is never written back to the device and field it was read from. Datacake would publish the value again and the flow would loop forever.

Errors (not connected, invalid payload, unknown device) are reported through the node and can be handled with a Catch node.

Upgrading from 0.x

Version 1.0 is a drop-in replacement. Existing flows keep working without changes:

• Token: 0.x stored the API token in plain text in the flow file. 1.0 still reads it, and the editor offers to move it to the encrypted credentials (a notification after loading the flows, or when the account is opened). Deploy once to complete the move.
• Values: existing datacake in nodes keep emitting strings. Choose Typed in a node to get numbers and booleans. New nodes are typed by default.
• Labels: nodes show device and field names right away. Names are loaded from Datacake when the editor opens, without changing the flow. Saving a node stores the names in the flow as a fallback.
• datacake out: 0.x offered Pass deviceId in msg object and All Measurements but ignored the message since 0.1.6. 1.0 handles them again as Device from msg.deviceId and Field from msg.fieldName, protected against loops.
• Messages keep payload, deviceId, productSlug and fieldName; topic and msg.datacake are new.
• Fixed: connections and listeners are no longer leaked on deploy (0.x opened a new connection with every full deploy and delivered each value once per connection), removed nodes unsubscribe their topics, nodes added by a partial deploy receive values immediately, and missing accounts no longer crash the flow.

Development

npm install
npm run build   # compile TypeScript and copy the editor files to dist/
npm test        # unit and integration tests (in-process MQTT broker, fake Datacake API)
npm run lint

Try the nodes in a local Node-RED:

npm run build
cd ~/.node-red && npm install <path to this repository>
node-red

Runtime code is in src/*.ts and src/lib/, the editor in src/*.html, texts and help in src/locales/. After changes to .ts files run npm run build (or npm run watch) and restart Node-RED; after changes to .html files reload the editor too.

For tests the broker and API can be replaced with the environment variables DATACAKE_MQTT_URL and DATACAKE_API_URL.

Releasing

Releases are published to npm by GitHub Actions through trusted publishing, no npm token is stored in the repository. Bump version in package.json, update CHANGELOG.md, merge to master, then push a matching tag:

git tag v1.0.0 && git push origin v1.0.0

License

MIT