|By Jonas Jacobi||
|April 1, 2013 03:31 AM EDT||
At Kaazing, we have been experimenting with using a smartphone as a remote control for quite some time now. Those familiar with our demos may have seen our Zing-Pong demo (which is a “Pong”-style game using smartphones to control the paddles over WebSocket) or our Racer demo (which is a 3D Formula One car rendered in WebGL as a Chrome Experiment, and remotely controlled with a smartphone). These demos, along with the other demos we’ve created with Kaazing’s platform, use no plug-ins. You simply point a browser on your computer to the address of the object you want to control (for example, the gorgeous Formula One car rendered in WebGL) and a browser from your smartphone to the address of the remote control (an ID we generate for you). Once connected, you just…go!
A couple of our Visionary Zingers, Prashant Khanal and David Witherspoon, then experimented with communicating with a Raspberry Pi using WebSocket–or, more specifically, using Kaazing’s JMS-over-WebSocket Gateway to tell Raspberry Pi to turn on and off a lightbulb. When the lightbulb turned on in this experiment, another lightbulb turned on: could we in fact turn a remote, radio-controlled car into a remote, WebSocket-controlled car? By controlling the car over the Web, could we control the car from another room? From another continent?
The Racer Demo
Let’s first take a closer look at the Racer demo. The Racer demo uses the reflector pattern: where we connect devices through a WebSocket server, thus simulating peer-to-peer connectivity, a very easy-to-achieve task using pub/sub. When we developed the Racer demo, we walked through the steps to build it in The Simplest Way to Use Your Smartphone as a Game Controller: A WebSocket Race Car Demo. By examining how to use pub/sub concepts to control a virtual car, it’s not so farfetched to consider doing the same with a radio-controlled car.
After working with the Racer demo, we knew what we wanted to achieve: controlling a “real” car (or at least a good-sized monster truck model) with a simple web app on a smartphone. Something like this, for example:
And something that might move like this:
In just a few hours of hacking and experimenting, we turned this radio-controlled car into a WebSocket-controlled car. Don’t worry, no actual cars (or bunnies) were harmed in the making of this demo, as you’ll see as we walk through the hardware and software we used.
Ingredients: The Hardware
- One RC car. We ended up using a black F150. The bigger the car, the easier it is to connect, position, and hide the building blocks. One thing to pay attention to is that the car you’re about to buy has to have two simple motors, one that drives the vehicle forward/backward, and another one that steers the car: front wheels left/right. The first thing you’ll get rid of is the radio control, so don’t worry about that too much.
- One Raspberry Pi, model B. This piece of hardware is incredible. Runs Linux (and Java), has 512MB RAM, an Ethernet port, 2 USB ports (for keyboard, mouse, WiFi), takes an SD card, has an HDMI out, and has a handful of GPIO (General Purpose Input/Output) pins to drive external devices, like lights, motors, and alike.
- One small breadboard. This simplifies connecting the building blocks.
- Set of male to male and male to female jumper leads.
- L298N Board: It is used to control the car motors. The car is equipped with two motors – one for steering and the other to drive wheels. Each motor is controlled through two GPIO pins.
- A couple of LEDs – optional. This RC car model didn’t come with any lights, but who has seen a serious RC car without lights – so we equipped ours with remote controllable LEDs.
- One smartphone (can be substituted by a tablet, or any Web browser, really). Using a touch-based device makes the controlling more natural, but you can use any laptop/desktop browser with mouse/trackpad as well.
- Battery. Anker Astro 5600 mAh external battery pack powering the Raspberry Pi and connected circuits: LEDs and relays.
The circuit diagram regarding the wiring among the Raspberry Pi GPIO pins, L298N board and the car battery can be found here. The pin numbers specified for the Raspberry Pi in the circuit diagram refers to the physical pin location.
Ingredients: The Software
- WebSocket Java client code. The Kaazing Java client runs on the Raspberry Pi, receiving messages from the WebSocket server, and instructing the Raspberry Pi GPIO pins to control the car. Control of the GPIO pins is achieved through the Pi4J Library.
Reviewing the Hardware
We decided to hide all the electronics in the body of the car, but wanted to have the Raspberry Pi accessible and more importantly, visible. It’s sitting on the truck’s plateau, lightly taped to it, so it doesn’t fall off as the truck accelerates and comes to sudden stops (read: bumps into things).
On the right you can see the WiFi plugged into the top USB port (blue LED). On the left, you see the blue SD card. The GPIO ports are on the top left, connected to drive the two motors and the lights of the truck. The Raspberry Pi is powered through a micro USB port on the bottom left, leveraging a smartphone quick charger battery.
Reviewing the Software
To enable the Raspberry Pi to receive WebSocket messages from the browser client, we had to write some logic that runs on the Pi.
Since we plan to use this demo at trade shows, we wanted to make sure that we have a certain level of control over who controls the car and when. Therefore, we use a “secret” key that the remote control has to know to control the car. This key is sent to the code running on the Pi via a secured admin topic. Every message coming from the smartphone has to contain the same key. If it doesn’t, the message is thrown away.
The remote control client on the smartphone first asks for the key that identifies who can control the car.
Then, the HTML5 remote control code, which runs on the smartphone, first establishes a connection to the WebSocket server. It creates a JMS topic, and a producer (or publisher) for the topic. When done, the client is ready to start sending messages through the WebSocket gateway to the Java code running on the Pi. Every message contains the previously specified key as well, as a custom JMS message property.
Java Code Running on the Raspberry Pi
We chose to program the Raspberry Pi using Java. Instructions to install Java on the Raspberry Pi can be found here. The Java code on the raspberry requires both the JMS Kaazing Websocket Library to receive messages from the client, and the Pi4J library to interact with the car through the Rasbperry Pi’s GPIO .
The code is split into two main classes, CommandReceiver and Car. CommandReceiver is responsible for connecting to the Kaazing JMS Gateway and listening to both on the command and the admin topic. When admin messages are received the CommandReceiver will record which user has valid access to control the car. When a command message is received, its properties will be checked to see if it is the current user in control of the car. If so, the message will be parsed and read, resulting in a corresponding method being called on the Car class.
The Car class is an abstraction of everything the car may do. It has methods such as Steering, Thrust, and Lights that are called with Command parameters such as ON, OFF, LEFT, and RIGHT. When called, the GPIO inputs corresponding to each method and are switched on or off, thereby resulting on the motors of the car moving forward, backwards, or steering left or right.
To check out or download the full source code visit KaazingPi on Github.
Well, we cheated and already showed the video of the result at the beginning. But, if you want to see it in person, come see us at one of our upcoming events:
- HTML5DevConf: 1-2 April 2013. Palace Hotel, San Francisco
- NABSHOW: 6-11 April 2013. Las Vegas Convention Center, Las Vegas
- SIFMA Tech: 18-19 June 2013. Hilton New York, New York
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at @ThingsExpo, James Kirkland, Red Hat's Chief Architect for the Internet of Things and Intelligent Systems, described how to revolutionize your archit...
Jul. 28, 2015 06:30 PM EDT Reads: 1,370
It is one thing to build single industrial IoT applications, but what will it take to build the Smart Cities and truly society-changing applications of the future? The technology won’t be the problem, it will be the number of parties that need to work together and be aligned in their motivation to succeed. In his session at @ThingsExpo, Jason Mondanaro, Director, Product Management at Metanga, discussed how you can plan to cooperate, partner, and form lasting all-star teams to change the world and it starts with business models and monetization strategies.
Jul. 28, 2015 04:30 PM EDT Reads: 1,750
The Internet of Everything (IoE) brings together people, process, data and things to make networked connections more relevant and valuable than ever before – transforming information into knowledge and knowledge into wisdom. IoE creates new capabilities, richer experiences, and unprecedented opportunities to improve business and government operations, decision making and mission support capabilities.
Jul. 28, 2015 04:00 PM EDT Reads: 215
The Internet of Things is not only adding billions of sensors and billions of terabytes to the Internet. It is also forcing a fundamental change in the way we envision Information Technology. For the first time, more data is being created by devices at the edge of the Internet rather than from centralized systems. What does this mean for today's IT professional? In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists addressed this very serious issue of profound change in the industry.
Jul. 28, 2015 03:00 PM EDT Reads: 1,246
Discussions about cloud computing are evolving into discussions about enterprise IT in general. As enterprises increasingly migrate toward their own unique clouds, new issues such as the use of containers and microservices emerge to keep things interesting. In this Power Panel at 16th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the state of cloud computing today, and what enterprise IT professionals need to know about how the latest topics and trends affect their organization.
Jul. 28, 2015 02:00 PM EDT Reads: 1,156
SYS-CON Events announced today that HPM Networks will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. For 20 years, HPM Networks has been integrating technology solutions that solve complex business challenges. HPM Networks has designed solutions for both SMB and enterprise customers throughout the San Francisco Bay Area.
Jul. 28, 2015 11:45 AM EDT Reads: 407
For IoT to grow as quickly as analyst firms’ project, a lot is going to fall on developers to quickly bring applications to market. But the lack of a standard development platform threatens to slow growth and make application development more time consuming and costly, much like we’ve seen in the mobile space. In his session at @ThingsExpo, Mike Weiner, Product Manager of the Omega DevCloud with KORE Telematics Inc., discussed the evolving requirements for developers as IoT matures and conducted a live demonstration of how quickly application development can happen when the need to comply wit...
Jul. 28, 2015 11:15 AM EDT Reads: 220
Converging digital disruptions is creating a major sea change - Cisco calls this the Internet of Everything (IoE). IoE is the network connection of People, Process, Data and Things, fueled by Cloud, Mobile, Social, Analytics and Security, and it represents a $19Trillion value-at-stake over the next 10 years. In her keynote at @ThingsExpo, Manjula Talreja, VP of Cisco Consulting Services, discussed IoE and the enormous opportunities it provides to public and private firms alike. She will share what businesses must do to thrive in the IoE economy, citing examples from several industry sectors.
Jul. 28, 2015 11:00 AM EDT Reads: 2,026
Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Opening Keynote at 16th Cloud Expo, Sandy Carter, IBM General Manager Cloud Ecosystem and Developers, and a Social Business Evangelist, d...
Jul. 27, 2015 09:00 PM EDT Reads: 2,037
There will be 150 billion connected devices by 2020. New digital businesses have already disrupted value chains across every industry. APIs are at the center of the digital business. You need to understand what assets you have that can be exposed digitally, what their digital value chain is, and how to create an effective business model around that value chain to compete in this economy. No enterprise can be complacent and not engage in the digital economy. Learn how to be the disruptor and not the disruptee.
Jul. 27, 2015 10:00 AM EDT Reads: 2,017
Akana has released Envision, an enhanced API analytics platform that helps enterprises mine critical insights across their digital eco-systems, understand their customers and partners and offer value-added personalized services. “In today’s digital economy, data-driven insights are proving to be a key differentiator for businesses. Understanding the data that is being tunneled through their APIs and how it can be used to optimize their business and operations is of paramount importance,” said Alistair Farquharson, CTO of Akana.
Jul. 27, 2015 09:00 AM EDT Reads: 270
Business as usual for IT is evolving into a "Make or Buy" decision on a service-by-service conversation with input from the LOBs. How does your organization move forward with cloud? In his general session at 16th Cloud Expo, Paul Maravei, Regional Sales Manager, Hybrid Cloud and Managed Services at Cisco, discusses how Cisco and its partners offer a market-leading portfolio and ecosystem of cloud infrastructure and application services that allow you to uniquely and securely combine cloud business applications and services across multiple cloud delivery models.
Jul. 27, 2015 08:00 AM EDT Reads: 1,890
The enterprise market will drive IoT device adoption over the next five years. In his session at @ThingsExpo, John Greenough, an analyst at BI Intelligence, division of Business Insider, analyzed how companies will adopt IoT products and the associated cost of adopting those products. John Greenough is the lead analyst covering the Internet of Things for BI Intelligence- Business Insider’s paid research service. Numerous IoT companies have cited his analysis of the IoT. Prior to joining BI Intelligence, he worked analyzing bank technology for Corporate Insight and The Clearing House Payment...
Jul. 26, 2015 09:00 PM EDT Reads: 1,555
In his keynote at 16th Cloud Expo, Rodney Rogers, CEO of Virtustream, discussed the evolution of the company from inception to its recent acquisition by EMC – including personal insights, lessons learned (and some WTF moments) along the way. Learn how Virtustream’s unique approach of combining the economics and elasticity of the consumer cloud model with proper performance, application automation and security into a platform became a breakout success with enterprise customers and a natural fit for the EMC Federation.
Jul. 26, 2015 08:00 AM EDT Reads: 2,136
"Optimal Design is a technology integration and product development firm that specializes in connecting devices to the cloud," stated Joe Wascow, Co-Founder & CMO of Optimal Design, in this SYS-CON.tv interview at @ThingsExpo, held June 9-11, 2015, at the Javits Center in New York City.
Jul. 25, 2015 02:00 PM EDT Reads: 377
SYS-CON Events announced today that CommVault has been named “Bronze Sponsor” of SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. A singular vision – a belief in a better way to address current and future data management needs – guides CommVault in the development of Singular Information Management® solutions for high-performance data protection, universal availability and simplified management of data on complex storage networks. CommVault's exclusive single-platform architecture gives companies unp...
Jul. 25, 2015 01:00 PM EDT Reads: 1,936
Electric Cloud and Arynga have announced a product integration partnership that will bring Continuous Delivery solutions to the automotive Internet-of-Things (IoT) market. The joint solution will help automotive manufacturers, OEMs and system integrators adopt DevOps automation and Continuous Delivery practices that reduce software build and release cycle times within the complex and specific parameters of embedded and IoT software systems.
Jul. 25, 2015 12:15 PM EDT Reads: 442
"ciqada is a combined platform of hardware modules and server products that lets people take their existing devices or new devices and lets them be accessible over the Internet for their users," noted Geoff Engelstein of ciqada, a division of Mars International, in this SYS-CON.tv interview at @ThingsExpo, held June 9-11, 2015, at the Javits Center in New York City.
Jul. 25, 2015 12:00 PM EDT Reads: 1,517
Internet of Things is moving from being a hype to a reality. Experts estimate that internet connected cars will grow to 152 million, while over 100 million internet connected wireless light bulbs and lamps will be operational by 2020. These and many other intriguing statistics highlight the importance of Internet powered devices and how market penetration is going to multiply many times over in the next few years.
Jul. 25, 2015 09:00 AM EDT Reads: 1,480
SYS-CON Events announced today that Dyn, the worldwide leader in Internet Performance, will exhibit at SYS-CON's 17th International Cloud Expo®, which will take place on November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Dyn is a cloud-based Internet Performance company. Dyn helps companies monitor, control, and optimize online infrastructure for an exceptional end-user experience. Through a world-class network and unrivaled, objective intelligence into Internet conditions, Dyn ensures traffic gets delivered faster, safer, and more reliably than ever.
Jul. 24, 2015 11:00 PM EDT Reads: 2,043