Programming IoT Gateways in JavaScript with macchina.io
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This document discusses programming IoT gateways using JavaScript with the macchina.io toolkit. Macchina.io is an open source modular toolkit for building embedded IoT applications that connect sensors, devices, and cloud services. It uses C++ for performance but includes a JavaScript interface. The document provides an overview of macchina.io and its components, demonstrates how to use JavaScript to access sensors and cloud services, and provides an example of logging sensor data to a database and sending SMS alerts based on sensor readings.
![// sensors.js (search sensors by physical quantity)
var sensors = {};
var illuminanceRefs = serviceRegistry.find(
'io.macchina.physicalQuantity == "illuminance"');
if (illuminanceRefs.length > 0)
{
sensors.illuminance = illuminanceRefs[0].instance();
}
var temperatureRefs = serviceRegistry.find(
'io.macchina.physicalQuantity == "temperature"');
if (temperatureRefs.length > 0)
{
sensors.temperature = temperatureRefs[0].instance();
}
var humidityRefs = serviceRegistry.find(
'io.macchina.physicalQuantity == "humidity"');
if (humidityRefs.length > 0)
{
sensors.humidity = humidityRefs[0].instance();
}
module.exports = sensors;](https://image.slidesharecdn.com/virtualiotmacchinaio-150723161209-lva1-app6891/85/Programming-IoT-Gateways-in-JavaScript-with-macchina-io-23-320.jpg)
![// history.jss
var db = require(‘../database.js');
var validItems = ['temperature', 'humidity', 'illuminance'];
var data = [];
db.session.pageSize = form.maxItems ? parseInt(form.maxItems) : 20;
var item = form.item;
if (validItems.indexOf(item) > -1)
{
var recordSet = db.session.execute(
'SELECT timestamp, ' + item + ' FROM datalog ORDER BY timestamp DESC');](https://image.slidesharecdn.com/virtualiotmacchinaio-150723161209-lva1-app6891/85/Programming-IoT-Gateways-in-JavaScript-with-macchina-io-28-320.jpg)
![// history.jss (continued)
for (var row = 0; row < recordSet.rowCount; row++)
{
var time = recordSet.getValue('timestamp');
var value = recordSet.getValue(item);
var date = LocalDateTime('1970-01-01');
date.addSeconds(time);
data[recordSet.rowCount - row - 1] =
{
timestamp: date.format('%H:%M:%S'),
value: value
};
recordSet.moveNext();
}
recordSet.close();
}
response.contentType = 'application/json';
response.write(JSON.stringify(data));
response.send();](https://image.slidesharecdn.com/virtualiotmacchinaio-150723161209-lva1-app6891/85/Programming-IoT-Gateways-in-JavaScript-with-macchina-io-29-320.jpg)
![// MQTT to AirVantage
var sensors = require('sensors.js');
var mqttClientRefs = serviceRegistry.find(
'io.macchina.mqtt.serverURI == "tcp://na.airvantage.net:1883"');
if (mqttClientRefs.length > 0)
{
logger.information("MQTT Client found!");
var mqttClient = mqttClientRefs[0].instance();
setInterval(function() {
var epoch = "" + 1000*DateTime().epoch; // seconds to milliseconds
var payload = {};
payload[epoch] = {
"sensors.temperature": sensors.temperature.value(),
"sensors.humidity": sensors.humidity.value()
"sensors.illuminance": sensors.illuminance.value()
};
mqttClient.publish('JA347400060803/messages/json',
JSON.stringify(payload), 0);
}, 10000);
}](https://image.slidesharecdn.com/virtualiotmacchinaio-150723161209-lva1-app6891/85/Programming-IoT-Gateways-in-JavaScript-with-macchina-io-30-320.jpg)
Programming IoT Gateways in JavaScript with macchina.io
- 1. Programming IoT Gateways in JavaScript with macchina.io Günter Obiltschnig Applied Informatics Software Engineering GmbH guenter@appinf.com @obiltschnig, @macchina_io
- 2. About Me hard-core C++ developer (20+ years), who also likes JavaScript “full stack++”, embedded, hardware to web frontend + cloud POCO C++ Libraries (2004) Applied Informatics GmbH (2006) my-devices.net (2010) AIS Radar for iOS (2011) macchina.io (2013)
- 3. m .ioacchina A modular open source toolkit for building embedded IoT applications that connect sensors, devices and cloud services.
- 4. IoT Gateway devices.netCloud Services AirVantage, Bluemix, Tinamous, Xively, etc. HTTP(S) MQTT Remote Access my-devices.net device apps local“business logic” web services web visualization database discoverability Mobile/Web Clients Devices/Sensor Networks CoAP, IEEE 802.15.4, Modbus, USB, Bluetooth, RS-232
- 6. > open source (Apache 2.0 License) > built in C++ for best performance and efficiency (JavaScript for parts of web interface) > modular and extensible > mature, proven codebase: POCO C++ Libraries, Google V8, Eclipse Paho, SQLite AngularJS, jQuery, OpenLayers, Ace (text editor), + Applied Informatics OSP and Remoting frameworks > C++-to-JavaScript bridge > Raspberry Pi, Beaglebone, Edison, RED, MangOH, etc. > prototype on Linux or OS X host, easily deploy to device > web interface with JavaScript editor
- 7. Sensors & Devices Protocols Cloud Services Temperature, Ambient Light, Humidity, Air Pressure, etc. HTTP AirVantage I/O, Trigger, Rotary Encoder MQTT Bluemix Accelerometer CoAP* Twitter GNSS/GPS WebEvent Twilio (SMS) Barcode Reader, RFID* WebTunnel my-devices.net XBee (ZigBee, IEEE 802.15.4) XBee API any with HTTP/REST APIs Serial Port Modbus*, CANopen* * planned
- 8. Pro Users and Device Manufacturers > add device specific APIs > make devices programmable in JavaScript for partners or end users > device specific app store (sell additional software features) > additional frameworks (UPnP, Remoting SOAP and JSON-RPC) > customizable web user interface > improved user authentication and authorization > signed bundles > pro support
- 9. Demo
- 12. POCO C++ Libraries > Started 2004 > ~300.000 LOC > 1000+ classes > on GitHub since 2012 1000+ stars 400+ forks 30-50 clones/day > ~100 contributors > Boost License > http://pocoproject.org POSIX, WIN32, other (RT)OS API Foundation C++ and C Standard LibrariesApplication Zip Net Crypto Data SQLite ODBC MySQL NetSSL Util Tools, Utilities and additional Libraries XML JSON
- 13. V8 > Google’s JavaScript Engine > Used by Chrome/Chromium and node.js > C++ library, (reasonably) easy to integrate and to extend > Compiles JavaScript to native code (x86, ARM, MIPS) > Great performance > BSD License
- 14. Remoting > Similar to .NET Remoting or Java RMI, but for C++ > Code generator parses annotated C++ header files and generates code (serialization/deserialization, method dispatching, helpers) > Supports different transports (binary TCP, SOAP, JSON-RPC) > Used for automatic C++-to-JavaScript bridging > Will also be used to implement sandbox mechanism
- 15. Open Service Platform (OSP) > Inspired by OSGi, but for C++ (also JavaScript, Python, etc.) > Dynamic module system based on bundles (Zip files with metadata, shared libs, other files) > Dependency and lifecycle management > Services and service registry > Web Server POCO Core Libraries (Foundation,XML,Util,Net) Operating System API Std.C/C++ Libraries Service Registry Portable Runtime Environment Life C ycle M anagem ent Bundle M anagem ent Standard Services Bundles install,resolve,start,stop and uninstall bundles provide services to other bundles and find services provided by other bundles manage bundle versions and dependencies web server, web- and console- based management, user authentication and authorization, preferences,etc. application-specific functionality and services
- 16. Combining POCO C++ Libraries and V8 > JavaScript is single-threaded and garbage-collected > POCO is multithreaded (specifically web server) > Make C++ object available to JavaScript easy for static objects, just provide Wrapper > Allow JavaScript code to create C++ objects easy if you don’t care about memory/resource leaks > Register a callback function called by GC when object is deleted allows you to properly delete underlying c++ object > However, V8 does not do callbacks when script ends wrapped C++ objects won’t be deleted, leaks resulting > Need to track every C++ object a script creates and clean up afterwards :-(
- 17. Automatic JavaScript Wrappers for C++ Objects
- 18. // Sensor.h //@ remote class Sensor: public Device { public: Poco::BasicEvent<const double> valueChanged; virtual double value() const = 0; virtual bool ready() const = 0; };
- 19. Sensor.h RemoteGen lots of generated source files RemoteGen.xml
- 20. Service <<generatedFrom>> IService ServiceProxy Service RemoteObject The interface class has all @remote methods from the service class. Service Skeleton <<invokes>> <<generated>> <<generated>><<generated>> <<generated>> Service ServerHelper <<generated>> Registers Skeleton, RemoteObject and EventDispatcher (if needed) with the Object Request Broker. Service ProxyFactory <<creates>> <<generated>> Service ClientHelper <<generated>> Registers ProxyFactory with the Object Request Broker. <<registers>><<registers>> <<registers>> Service EventSubscriber <<generated>> Service EventDispatcher <<generated>> <<registers>>
- 21. var tempSensor = ...; tempSensor.on(‘valueChanged', function(ev) { var temp = ev.data; // ... }); if (tempSensor.ready()) { var temp = tempSensor.value(); // ... }
- 23. // sensors.js (search sensors by physical quantity) var sensors = {}; var illuminanceRefs = serviceRegistry.find( 'io.macchina.physicalQuantity == "illuminance"'); if (illuminanceRefs.length > 0) { sensors.illuminance = illuminanceRefs[0].instance(); } var temperatureRefs = serviceRegistry.find( 'io.macchina.physicalQuantity == "temperature"'); if (temperatureRefs.length > 0) { sensors.temperature = temperatureRefs[0].instance(); } var humidityRefs = serviceRegistry.find( 'io.macchina.physicalQuantity == "humidity"'); if (humidityRefs.length > 0) { sensors.humidity = humidityRefs[0].instance(); } module.exports = sensors;
- 24. // sensors.js (search sensors by ID) var sensors = {}; var illuminanceRef = serviceRegistry.findByName( 'io.macchina.xbee.sensor.illuminance#0013A20040A4D7F7'); if (illuminanceRef) { sensors.illuminance = illuminanceRef.instance(); } var temperatureRef = serviceRegistry.findByName( 'io.macchina.xbee.sensor.temperature#0013A20040A4D7F7'); if (temperatureRef) { sensors.temperature = temperatureRef.instance(); } var humidityRef = serviceRegistry.findByName( 'io.macchina.xbee.sensor.humidity#0013A20040A4D7F7'); if (humidityRef) { sensors.humidity = humidityRef.instance(); } module.exports = sensors;
- 25. // database.js var database = {}; database.path = bundle.persistentDirectory + "logger.db"; database.session = new DBSession('SQLite', database.path); database.logIntervalSeconds = application.config.getInt( "datalogger.intervalSeconds", 30); database.keepDataSeconds = application.config.getInt( "datalogger.keepDataSeconds", 3600); module.exports = database;
- 26. // logger.js var sensors = require('sensors.js'); var db = require('database.js'); db.session.execute('PRAGMA journal_mode=WAL'); db.session.execute('CREATE TABLE IF NOT EXISTS datalog ( timestamp INTEGER, illuminance FLOAT, temperature FLOAT, humidity FLOAT )'); setInterval( function() { db.session.execute('INSERT INTO datalog VALUES (?, ?, ?, ?)', DateTime().epoch, sensors.illuminance.value(), sensors.temperature.value(), sensors.humidity.value()); }, db.logIntervalSeconds*1000);
- 27. // logger.js (continued) setInterval( function() { var cutoffTime = DateTime().epoch - db.keepDataSeconds; db.session.execute('DELETE FROM datalog WHERE timestamp < ?', cutoffTime); }, db.keepDataSeconds*1000);
- 28. // history.jss var db = require(‘../database.js'); var validItems = ['temperature', 'humidity', 'illuminance']; var data = []; db.session.pageSize = form.maxItems ? parseInt(form.maxItems) : 20; var item = form.item; if (validItems.indexOf(item) > -1) { var recordSet = db.session.execute( 'SELECT timestamp, ' + item + ' FROM datalog ORDER BY timestamp DESC');
- 29. // history.jss (continued) for (var row = 0; row < recordSet.rowCount; row++) { var time = recordSet.getValue('timestamp'); var value = recordSet.getValue(item); var date = LocalDateTime('1970-01-01'); date.addSeconds(time); data[recordSet.rowCount - row - 1] = { timestamp: date.format('%H:%M:%S'), value: value }; recordSet.moveNext(); } recordSet.close(); } response.contentType = 'application/json'; response.write(JSON.stringify(data)); response.send();
- 30. // MQTT to AirVantage var sensors = require('sensors.js'); var mqttClientRefs = serviceRegistry.find( 'io.macchina.mqtt.serverURI == "tcp://na.airvantage.net:1883"'); if (mqttClientRefs.length > 0) { logger.information("MQTT Client found!"); var mqttClient = mqttClientRefs[0].instance(); setInterval(function() { var epoch = "" + 1000*DateTime().epoch; // seconds to milliseconds var payload = {}; payload[epoch] = { "sensors.temperature": sensors.temperature.value(), "sensors.humidity": sensors.humidity.value() "sensors.illuminance": sensors.illuminance.value() }; mqttClient.publish('JA347400060803/messages/json', JSON.stringify(payload), 0); }, 10000); }
- 31. // Send SMS via Twilio function sendSMS(to, message) { var accountSID = application.config.getString("twilio.accountSID"); var authToken = application.config.getString("twilio.authToken"); var from = application.config.getString(“twilio.from"); var twilioHttpRequest = new HTTPRequest( "POST", "https://api.twilio.com/2010-04-01/Accounts/" + accountSID + "/SMS/Messages" ); twilioHttpRequest.authenticate(accountSID, authToken); twilioHttpRequest.contentType = "application/x-www-form-urlencoded"; twilioHttpRequest.content = "From=" + encodeURIComponent(from) + "&To=" + encodeURIComponent(to) + "&Body=" + encodeURIComponent(message); twilioHttpRequest.send(function(result) { logger.information("Twilio SMS Response: ", result.response.status, result.response.content); }); }
- 32. var sensors = require('sensors.js'); var enableSMS = true; sensors.illuminance.on('valueChanged', function(ev) { logger.notice("valueChanged: " + ev.data); if (ev.data < 10) { logger.warning("Lights out!"); if (enableSMS) { sendSMS("+436765166737", "Lights out!"); enableSMS = false; } } else if (ev.data > 50) { enableSMS = true; } });
- 33. Q&A
- 34. guenter@appinf.com | @obiltschnig | obiltschnig.com macchina.io | my-devices.net | pocoproject.org | www.appinf.com