Embedded Internet

Simply put, the marriage between embedded systems and Internet technology is what is known as Embedded Internet. The synergy between the two has opened up a whole range of opportunities, offering more than the sum of its parts. The prime reason for this is that Internet technologies have provided embedded systems a standard way of communicating, which was not the case earlier. That's why you hear of great things like the ability to remotely monitor the progress of production lines, or the ability to remotely control your home appliances like washing machine, fridge, etc. In the corporate world, one hears of the ability to remotely monitor and control the various security devices, peripherals, building control, etc. Let's understand the concept of embedded Internet in more detail and why it's become so popular. 

How it evolved



Back in the olden days, most embedded systems developed were proprietary in nature. They ran some Real Time OS, and the applications were programmed using C or assembly language. So in case anybody wanted to upgrade the software to a better version, it would either cost a bomb or would be very expensive. Moreover, as the need for enabling communication between various embedded devices grew, these proprietary systems hit a dead end. It was a nightmare to try and make them talk to each other. The communication could be done using the built-in UART (Universal Asynchronous Receiver/Transmitter) of the embedded system, Ethernet, CAN (Controller Area Network), or some other non-standard technique. Basically there was no single standard way that everyone could use for enabling communication between different embedded systems. That's where the concept of embedded Internet was introduced and caught on like wild fire. 

The concept 

Most network printers have an embedded Web server to manage them remotely

The Internet as everyone knows is a large network of different hosts, which can communicate with each other. The hosts on the Internet initially were servers and PCs. However, this has changed over time and today, you can control just about anything over the Internet, some of which we mentioned in the beginning. The communication happens over TCP/IP, which is a standard protocol, and web servers are used on each host to respond to requests from other hosts. The interface for accessing the web servers is of course the web browser. Embedded systems market took advantage of this protocol and built a lightweight stack of it, which could be fitted on any device. Plus, a web server was also embedded on the device, which was accessible over a web browser. 

By now, you can easily figure out the similarity between the Internet and Embedded Internet. The embedded system runs a web server controlled by a microcontroller, with the data (web pages) stored on an EEPROM. The embedded device also has an IP address due to the embedded lightweight TCP/IP stack. This is accessible from a web browser from any client anywhere in the world. The web server is then linked to the application running on the embedded device. So a client can access the embedded device over the Internet, and give it commands. The commands are received by the web server and then forwarded to the application for processing. 

Embedded Internet is being implemented in a number of ways. Sun Microsystems, for instance developed the Java 2 Micro Edition (J2ME) standard. This is a development language that combines a small-footprint JVM (Java virtual machine) with a set of APIs for use in a range of embedded applications. In such a system, distributed control is accomplished by transferring HTML pages from the browser to the embedded web server and executing Java applets. Similar to Java, many other vendors have also implemented Internet technologies in different ways. 

As you can imagine by now, Internet technology has taken the world of embedded systems by storm, and provided it a standard way of communication and networking. ¨