Tiny House temperature monitoring using Node-RED and LoRa

Overview

• In this lesson - temperature and humidity data from a Tiny House was collected using a Pycom LoPy4 and transmitted to a local LoRa WAN Gateway
• The data was processed in The Things Network
• The data was subscribed to using MQTT using Node-RED
• A time stamp was added simple time node
• The data was processed using a process node to extract out temperature data
• The data was then packaged so that it cold be dweeted.
• The data will be available to students as a Dweet so that they can monitor the performance of their tiny house
• Students will use Python to process the dweeted data (Dweepy module)

MQTT

MQTT is a publish/subscribe messaging protocol designed for IoT. Every application on TTS automatically exposes an MQTT endpoint. In order to connect to the MQTT server you need to create a new API key, which will function as connection password. You can also use an existing API key, as long as it has the necessary rights granted.

MQTT is available via Applications > Integrations > MQTT in The Things Network

API Keys

• New Password API Keys can be generated by clicking on the Generate New API Key button.
• If an API Key already exists it can be copied from Go to API Keys button.
• If an existing API Key cannot be copied it can easily be regenerated.

Node-RED Configuration

mqqt-in Node

mqqt-in edit Node - Connection

• Click on the Edit button to the right of the Server entry to edit the mqtt node

• Follow the example below to configure the connection to the MQQT broker on The Things Network

mqqt-in edit Node - Security

• Follow the example below for the security configuration.
• Note that the username is whi-tinyhouse-12-temperature-pycom@ttn
• Whereas the password is a very long chanracter set (40+ characters) obtained from the The Things Network Application page.
• For security reasons, Node-RED will not retain any passwords if the node is copied.

simpletime Node

• simpletime adds time and date stamps to the data flow within Node-RED.
• The simpletime node needs to be added to Node-RED using the Manage pallet function.

• Example of default configuration of simpletime node.

function Node

• The function node is used to process data flows in Node-RED.

• In this example the function node is used to:
  • Extract temperature, humidity and battery data from the mqtt in data feed
  • Then assign the data to variables
  • And finally, dweet the data so that the data is available to students on the internet.

• Code reproduced below.
• Add your own unique dweet address to the code.
• The dweet address also requires the question mark symbol at the end - <My_Dweet_address>?

var battery; // battery voltage data
var int_humidity; // humidity data from within the sensor housing
var ext_temp; // external temperature data
var int_temp; // temperature data from within the sensor housing

battery = msg.payload.uplink_message.decoded_payload.bat;
int_humidity = msg.payload.uplink_message.decoded_payload.humid;
ext_temp = msg.payload.uplink_message.decoded_payload.onewire_temp;
int_temp = msg.payload.uplink_message.decoded_payload.temp;

msg.payload = "bat=" + String(battery) + "&"
    + "intHumid=" + String(int_humidity) + "&"
    + "extTemp=" + String(ext_temp) + "&"
    + "intTemp=" + String(int_temp) + "&"
    + "date=" + String(msg.myymd) + " " + String(msg.mytimes);

msg.url = "https://dweet.io/dweet/for/<My_Dweet_address>?" + msg.payload;

// check dweet with - https://dweet.io/get/latest/dweet/for/<My_Dweet_address>
return msg;

http request Node

• The http request node is able to Dweet the data package using the POST http operation.

• The configuration of the http request node is shown below.
• The node has been named dweet tiny house 12 data (name is lower down in node edit window - not shown).

Node-RED code for flow

[
    {
        "id": "4a48c27d77b24951",
        "type": "tab",
        "label": "Tiny house 12",
        "disabled": false,
        "info": "",
        "env": []
    },
    {
        "id": "9eb5f086aba506f2",
        "type": "mqtt in",
        "z": "4a48c27d77b24951",
        "name": "whi-tinyhouse-12",
        "topic": "#",
        "qos": "0",
        "datatype": "json",
        "broker": "770475c1.8593ac",
        "nl": false,
        "rap": true,
        "rh": 0,
        "inputs": 0,
        "x": 100,
        "y": 60,
        "wires": [
            [
                "611459927e315292"
            ]
        ]
    },
    {
        "id": "1b6fa839582e5f27",
        "type": "debug",
        "z": "4a48c27d77b24951",
        "name": "debug 1",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "payload",
        "targetType": "msg",
        "statusVal": "",
        "statusType": "auto",
        "x": 660,
        "y": 200,
        "wires": []
    },
    {
        "id": "42efdbdb620f1c41",
        "type": "function",
        "z": "4a48c27d77b24951",
        "name": "process tiny house 12 data",
        "func": "var battery; // battery voltage data\nvar int_humidity; // humidity data from within the sensor housing\nvar ext_temp; // external temperature data\nvar int_temp; // temperature data from within the sensor housing\n\nbattery = msg.payload.uplink_message.decoded_payload.bat;\nint_humidity = msg.payload.uplink_message.decoded_payload.humid;\next_temp = msg.payload.uplink_message.decoded_payload.onewire_temp;\nint_temp = msg.payload.uplink_message.decoded_payload.temp;\n\nmsg.payload = \"bat=\" + String(battery) + \"&\"\n    + \"intHumid=\" + String(int_humidity) + \"&\"\n    + \"extTemp=\" + String(ext_temp) + \"&\"\n    + \"intTemp=\" + String(int_temp) + \"&\"\n    + \"date=\" + String(msg.myymd) + \" \" + String(msg.mytimes);\n\nmsg.url = \"https://dweet.io/dweet/for/SMC-Tiny-House-12-bundoora?\" + msg.payload;\n\n// check dweet with - https://dweet.io/get/latest/dweet/for/<My_Dweet_address>\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 520,
        "y": 120,
        "wires": [
            [
                "510be4e1f5acfe72"
            ]
        ]
    },
    {
        "id": "611459927e315292",
        "type": "simpletime",
        "z": "4a48c27d77b24951",
        "name": "",
        "mydate": true,
        "myymd": true,
        "myyear": true,
        "mymonth": true,
        "mymonthn": true,
        "mydom": true,
        "mydoy": true,
        "myday": true,
        "myhourpm": true,
        "myhour": true,
        "mytime": true,
        "mytimes": true,
        "myminute": true,
        "myminutes": true,
        "mysecond": true,
        "mymillis": true,
        "myepoch": true,
        "myrawdate": true,
        "mypm": true,
        "x": 290,
        "y": 60,
        "wires": [
            [
                "42efdbdb620f1c41",
                "98d5072b7123bd5f"
            ]
        ]
    },
    {
        "id": "98d5072b7123bd5f",
        "type": "debug",
        "z": "4a48c27d77b24951",
        "name": "debug 2",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 680,
        "y": 60,
        "wires": []
    },
    {
        "id": "510be4e1f5acfe72",
        "type": "http request",
        "z": "4a48c27d77b24951",
        "name": "dweet tiny house 12 data",
        "method": "POST",
        "ret": "obj",
        "paytoqs": "body",
        "url": "",
        "tls": "",
        "persist": false,
        "proxy": "",
        "insecureHTTPParser": false,
        "authType": "",
        "senderr": false,
        "headers": [],
        "x": 410,
        "y": 200,
        "wires": [
            [
                "1b6fa839582e5f27"
            ]
        ]
    },
    {
        "id": "770475c1.8593ac",
        "type": "mqtt-broker",
        "name": "whi-tinyhouse-12",
        "broker": "au1.cloud.thethings.network",
        "port": "1883",
        "clientid": "",
        "autoConnect": true,
        "usetls": false,
        "protocolVersion": "4",
        "keepalive": "60",
        "cleansession": true,
        "birthTopic": "",
        "birthQos": "0",
        "birthPayload": "",
        "birthMsg": {},
        "closeTopic": "",
        "closeQos": "0",
        "closePayload": "",
        "closeMsg": {},
        "willTopic": "",
        "willQos": "0",
        "willPayload": "",
        "willMsg": {},
        "userProps": "",
        "sessionExpiry": ""
    }
]