Workflow: HTTP Mqtt Monitor

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    "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": "={{ $json.payload }}",
                "method": "POST",
                "options": [],
                "sendBody": true,
                "contentType": "raw",
                "sendHeaders": true,
                "headerParameters": {
                    "parameters": [
                        {
                            "name": "Authorization",
                            "value": "Token  <API Token value generated in InfluxDB>"
                        }
                    ]
                }
            },
            "notesInFlow": true,
            "typeVersion": 4.20000000000000017763568394002504646778106689453125
        },
        {
            "id": "6abe1212-b128-492f-b485-401a4315fcbc",
            "name": "Payload data preparation node",
            "type": "n8n-nodes-base.code",
            "position": [
                -180,
                -220
            ],
            "parameters": {
                "jsCode": "\/\/ Try to parse the incoming message as JSON\nlet data;\ntry {\n  data = JSON.parse($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
                    }
                ]
            ]
        }
    }
}