A Gadget Freak project on the Design News magazine Web site used an mbed (yes, it's all lower-case letters) microcontroller module to control one of those Billy Bass singing fish popular as a gag gift about 10 years ago. The mbed module looks like an interesting and simple way to get a quick start with an LPC1768 ARM Cortex-M3 microcontroller from NXP Semiconductors.

The people at mbed have placed the MCU on small circuit board with two rows of 20-pin contacts along each long edge. So, you can drop a module into a solderless breadboard or even into a final product. Just to prove good things do come in small packages, the module-and-chip package provides the 100-MHz Cortex-M3 core with 64 Kbytes of SRAM, and 512 Kbytes of flash memory. I/O devices include Ethernet, USB, SPI, I2C, UART, CAN, GPIO, PWM, a 12-bit ADC and a 10-bit DAC. (The built-in Ethernet port comes with an assigned MAC address.) That array of capabilities should keep developers happy for some time



Use the Online Compiler

One of the interesting features of the mbed approach is its use on an online compiler--the ARM RealView compiler engine--to create executable code. Because the compiler operates as a web-based application, you can use a compatible browser on a Windows, Mac OS, or Linux computer. To run a program, you simply transfer your executable file to the mbed module that appears as a simple USB memory stick. You don't have to install any code separately on your PC or in the mbed module. The compiler includes APIs for the MCU's I/O devices, so you don't get snarled in the intricacies of writing low-level driver code. I haven't tried the compiler, so I don't know how you protect intellectual property, but conceivable you could buy a set of ARM-compatible tools and work on your own, too.

The mbed operation sells an mbed module for about $US 99, but distributors such as DigiKey and Avnet accept pre-orders for about $US 60. The mbed modules are in their third version and mbed and its distributors expect to have them in stock by about mid November 2009, just a few weeks from now. Some developers have beta versions of the coming module and you can read about their experiences in the blog section of the mbed Web site. Visit the blog area: "Beta Testers - The First 5 Minutes."

Learn more about the mbed hardware and software and see the Handbook and Cookbook at: www.mbed.org.

Also, for the Design News Gadget Freak Case #150: Hotrod Your Billy Bass, go to: www.designnews.com/article/357086-Gadget_Freak_Case_150_Hotrod_Your_Billy_Bass.php.

I welcome comments about the mbed hardware and software. --Jon Titus