Weather Station Data From Tessel 2 via HTTP

Sending environmental data from Tessel 2 to SAP Cloud Platform IoT Service for Neo using HTTP protocol.

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Weather Station Data From Tessel 2 via HTTP

Things used in this project

Hardware components

Tessel 2 (main module)

Tessel Climate Module

Software apps and online services

SAP Cloud Platform IoT for the Neo environment

Story

It is one of many examples of different devices supplying environmental sensor data (temperature, humidity) to SAP Cloud Platform (SCP). Here Tessel 2 device is used. Sensor data will be send synchronously using HTTP REST protocol.

Prepare your Tessel 2 device

Make sure your went through Tessel's Climate tutorial http://tessel.github.io/t2-start/modules/climate.html prior to continuing with this project.

Make sure you have free developer account in SAP Cloud Platform

If you do not, please follow this tutorial first: https://www.sap.com/developer/tutorials/iot-part6-hcp-services.html

Configure virtual device for Tessel 2 in SCP

Follow the tutorial https://www.sap.com/developer/tutorials/iot-part7-add-device.html and then create a separate virtual device for your Tessel 2. Instead of "myDevice" you can call it "tessel2".

Create tessel2 device with device type weatherStation

Note down technical ID of this tessel2 virtual device and its assigned authorization token.

Modify the code

Modifying the attached JavaScript code provided below, you will need to add in your Message Type ID, Device ID, etc.

The lines in particular you will need to modify are the following:

var accountOwner = '<your account user>';
var messageTypeID = '<message type>';
var deviceId = '<device id>';
var authToken = '<auth token of the device>';

You should modify: - The accountOwner line to add your own SAP Cloud Platform Account User ID which starts with either an S , P , I , D or C .

The messageTypeID is the ID of the message type you created, and not the name of the message type.

The deviceId is the ID of the device you created, not to be confused with the token

The authToken line contains the token of the device (not the device type!). You received it in the pop-up window after creating your device. But if missed it, then regenerate this token from Device screen once again.

Save the file as scpiot_neo_tessel2_http.js

Run the code and check the results

Once you have saved your file, you will deploy and execute it from the command line (Windows) or terminal (Linux/Mac). t2 is the command line interface for Tessel2 devices.

Connect the device to the internet and run the following command:

t2 run

If everything is correct, then you should see something like this as the output.

Running the code on Windows

You can preview received data in the cloud in Message Management Service Cockpit and use the OData API link to now use this data in your applications!

Data preview in Message Management Service Cockpit

Have a good weather!

scpiot_neo_tessel2_http.js

var accountOwner = 'p1940048985'; // can be as well like 'p1940048985', 's000338523'
var messageTypeID = 'c6a49b942355d081949e';
var deviceId = 'bbf4a02f-45ad-4cc2-af90-18b68f7ce4ec';
var authToken = 'b3f90838e0c515e6ac71e9844af6e';
var portIoT = 443;
var hostIoT = 'iotmms'+accountOwner+'trial.hanatrial.ondemand.com';
var pathIoT = '/com.sap.iotservices.mms/v1/api/http/data/';
var authStrIoT = 'Bearer ' + authToken;

var tessel = require('tessel');
var climatelib = require('climate-si7020');
var climate = climatelib.use(tessel.port['A']);

climate.on('ready', function () {
	console.log('Connected to si7020');

	// Loop forever - every 5 secs
	setImmediate(function loop() {
		climate.readTemperature('c', function (err, temp) {
			climate.readHumidity(function (err, humid) {
				console.log('Degrees:', temp.toFixed(4) + 'C', 'Humidity:', humid.toFixed(4) + '%RH');
				updateIoT(temp.toFixed(4), humid.toFixed(4));
				setTimeout(loop, 5000);
			});
		});
	});
});

climate.on('error', function (err) {
	console.log('error connecting module', err);
});

function updateIoT(lv_temperature, lv_humidity) {
	var http = require('https');
	var options = {
		host : hostIoT,
		port : portIoT,
		path : pathIoT + deviceId,
		agent : false,
		headers : {
			'Authorization' : authStrIoT,
			'Content-Type' : 'application/json;charset=utf-8'
		},
		method : 'POST',
	};
	options.agent = new http.Agent(options);
	callback = function (response) {
		var body = '';
		response.on('data', function (data) {
			body += data;
		});
		response.on('end', function () {
			console.log("END:", response.statusCode, JSON.parse(body).msg);
		});
		response.on('error', function (e) {
			console.error(e);
		});
	}
	var req = http.request(options, callback);
	req.on('error', function (e) {
		console.error(e);
	});
	date = new Date();

	req.shouldKeepAlive = false;
	var jsonData = {
		"mode" : "sync",
		"messageType" : messageTypeID,
		"messages" : [{
				"temperature" : lv_temperature,
				"humidity" : lv_humidity,
				"timestamp" : date
			}
		]
	};

	var strData = JSON.stringify(jsonData);
	console.log("POST jsonData:" + strData);
	req.write(strData);
	req.end();
}