n8n-workflows/workflows/1110_HTTP_Mqtt_Monitor_Webhook.json

{
  "id": "6pOGYw5O3iOY1Gc6",
  "meta": {
    "instanceId": "7221598654c32899e94731aab144bdcd338735c2ac218dc0873131caa0be0ef8",
    "templateCredsSetupCompleted": true
  },
  "name": "Remote IOT Sensor monitoring via MQTT and InfluxDB",
  "tags": [],
  "nodes": [
    {
      "id": "4997f226-f236-4d27-bea4-904744d9ff07",
      "name": "Sticky Note",
      "type": "n8n-nodes-base.stickyNote",
      "position": [
        -700,
        -360
      ],
      "parameters": {
        "width": 340,
        "height": 120,
        "content": "MQTT trigger subscribed to a topic called wokwi-weather via a Mosquitto MQTT broker. The trigger receives the temperature and humidity payloads from a DHT22 sensor connected to a remote ESP32 microcontroller "
      },
      "typeVersion": 1
    },
    {
      "id": "9d4f1da6-fda3-4312-a6b1-bd0ac499dde7",
      "name": "Sticky Note1",
      "type": "n8n-nodes-base.stickyNote",
      "position": [
        -240,
        -360
      ],
      "parameters": {
        "height": 100,
        "content": "Javascript code to extract the temperature and humidity values to ensure correct JSON format for the database"
      },
      "typeVersion": 1
    },
    {
      "id": "d8f01dba-5019-457e-8c1a-99c802282fdf",
      "name": "Sticky Note3",
      "type": "n8n-nodes-base.stickyNote",
      "position": [
        140,
        -360
      ],
      "parameters": {
        "width": 260,
        "height": 120,
        "content": "HTTP request node posts temperature and humidity data from the DHT22 sensor to the InfluxDB data bucket running on a local host http://localhost:8086"
      },
      "typeVersion": 1
    },
    {
      "id": "020858a6-7771-4322-8eb6-b83e99b3563d",
      "name": "Remote Sensor MQTT Trigger",
      "type": "n8n-nodes-base.mqttTrigger",
      "position": [
        -580,
        -220
      ],
      "parameters": {
        "topics": "wokwi-weather",
        "options": {}
      },
      "credentials": {
        "mqtt": {
          "id": "xtd75tjk1hKlQOba",
          "name": "MQTT account"
        }
      },
      "typeVersion": 1
    },
    {
      "id": "51e6f59f-9b93-4121-8db4-7f47b929fdf5",
      "name": "Data ingest to InfluxDB bucket",
      "type": "n8n-nodes-base.httpRequest",
      "position": [
        200,
        -220
      ],
      "parameters": {
        "url": "http://localhost:8086/api/v2/write?orgID=<Organization ID>&bucket=<InfluxDB bucket name>&precision=s",
        "body": "={{ $json.payload }}",
        "method": "POST",
        "options": {},
        "sendBody": true,
        "contentType": "raw",
        "sendHeaders": true,
        "headerParameters": {
          "parameters": [
            {
              "name": "Authorization",
              "value": "Token  <API Token value generated in InfluxDB>"
            }
          ]
        }
      },
      "notesInFlow": true,
      "typeVersion": 4.2
    },
    {
      "id": "6abe1212-b128-492f-b485-401a4315fcbc",
      "name": "Payload data preparation node",
      "type": "n8n-nodes-base.code",
      "position": [
        -180,
        -220
      ],
      "parameters": {
        "jsCode": "// Try to parse the incoming message as JSON\nlet data;\ntry {\n  data = JSON.parse($json.message); // $json.message is expected to be a JSON string\n} catch (e) {\n  // If parsing fails, throw an error\n  throw new Error(\"Invalid JSON in MQTT message\");\n}\n\n// Get the topic from the input, or use a default value\nconst topic = $json.topic || \"unknown-topic\";\n\n// Make sure humidity and temp are numbers\nif (typeof data.humidity !== \"number\" || typeof data.temp !== \"number\") {\n  throw new Error(\"Missing or invalid humidity/temp in MQTT message\");\n}\n\n// Create a formatted string like: \"topic_name humidity=45,temp=22\"\nconst line = `${topic} humidity=${data.humidity},temp=${data.temp}`;\n\n// Return the result in the expected format\nreturn [\n  {\n    json: {\n      payload: line\n    }\n  }\n];"
      },
      "typeVersion": 2
    }
  ],
  "active": false,
  "pinData": {},
  "settings": {
    "executionOrder": "v1"
  },
  "versionId": "d1311dca-5edf-4f14-86b9-629937cd3416",
  "connections": {
    "Remote Sensor MQTT Trigger": {
      "main": [
        [
          {
            "node": "Payload data preparation node",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Payload data preparation node": {
      "main": [
        [
          {
            "node": "Data ingest to InfluxDB bucket",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  }
}