Issue 151 February 2003
Working the ’Net

BURNING DOWN THE ’NET

The previously described products are all designed to ease the process of migrating an existing application toward a network-based solution. Eventually, or if you’re starting from scratch, the time will come to consider consolidating your embedded application processing and networking to run on a single processor.

Enter NetBurner. Despite it’s small size (and price), don’t be fooled. Based on a 66-MHz Motorola MC5272 Cold-Fire chip (see Figure 1), NetBurner is a stand-alone 32-bit SBC with up to 512 KB of flash memory and a whopping 8 MB of SDRAM. Under the hood is a full-blown RTOS (µC/OS) and complete TCP/IP stack. Here, you’ll find every letter in the alphabet soup of protocols that handle web serving, e-mail, file transfer (i.e., FTP), and all the rest.

Figure 1—Where’s the kitchen sink? The Motorola MC5272 at the heart of NetBurner is a networking workhorse with built-in Ethernet, USB, SPI, and UARTs.

What separates NetBurner from many other 32-bit SBCs are specific utilities, libraries, and application examples that tailor the device for quick and easy (or at least quicker and easier) Internet apps. Tools start with the familiar GNU toolchain, including a C compiler, assembler, debugger, linker, and so on. However, those of you who have dabbled with GNU before know that merely manhandling the tools, not to mention getting any work done, is a nontrivial task.

To make life easier, NetBurner comes with a predefined make script that handles the messy details. Notably, this includes consolidating and compressing all related application and web files for packing into the flash memory. Then, after reset, NetBurner decompresses and transfers the code to SDRAM, which, in conjunction with the ’5272’s high-speed on-chip cache and RAM, delivers speedy processing.

For dynamic web pages, feel free to use all of the highfalutin techniques—such as Java applets, common gateway interface (CGI), and socket-level programming—that this 32-bit processor and its megs of memory can support. Just remember that even though the platform is downsized, such big-iron programming isn’t for beginners or the faint of heart.

NetBurner offers an easier way out with a "tagged HTML" approach similar to the one I described earlier for SitePlayer. The difference is that the NetBurner tags, rather than just displaying variables and objects, perform a C function call for unlimited processing capability (see Listing 1). A particular item that appears on the web browser’s screen might have 10 or 10,000 lines of code behind it.

I was impressed with the collection of nearly two-dozen example applications. They encompass everything from the simplest Hello World demo to e-mail, Telnet, PPP, UDP, FTP, and much more (see Photo 4). There’s just no better way to learn how to do something than to see how it’s done, and the examples will prove to be a helpful starting point for your own application.

Photo 4—With a TCP/IP stack and GNU development tools, NetBurner can do it all. For example, turning your embedded gadget into an FTP server provides an easy way to move application data to or from a file. Just copy and paste.