Rapid Arm Prototyping
Every Christmas season there's that hard-to-get toy. Tickle Me Elmo, the latest video game console, Cabbage Patch Kids, or some other kid-craze that you can't actually get. I found myself looking at a toy from the UK that apparently I can't get: the mbed microcontroller.
Well, perhaps microcontroller is too strong a word. It is actually a little PCB made to look like a DIP IC package (similar to how a Parallax Basic Stamp is made, but bigger than the typical Basic Stamp). On that little PCB is an NXP LPC1768 ARM processor (a Cortex-M3 processor with 512kB of flash and 64kB of RAM, USB, Ethernet, and other goodies).There's also a voltage regulator and clock, so the part is pretty much plug and play--it even includes a USB port on the board.
Of course, it isn't a big trick to make a little embedded board like this. There's plenty of them around. What struck me as novel about the mbed? First, the way you download your code to it. You don't need JTAG or a programmer (in fact, their web site stresses they don't provide JTAG). Instead, it looks like a USB drive on your computer and you just dump the firmware file into that drive. In addition, the development tools are hosted by mbed in your web browser. Of course, not so good if you are trying to do a firmware update in the middle of a swamp with no network (yes, I've done that). But I suspect most of us prototype near a broadband connection these days.
According to the mbed site, the suggested price of these modules is about US$100, but they are rolling them out at US$60. Sort of. Every time I've checked DigiKey for stock, they are back ordered. I don't know if that means they aren't showing up or if it means they are getting rapidly snatched up. From watching the videos on their site, I'm guessing they are getting snatched up. These look like great fun for prototyping or personal "one off" projects. And -- presuming my wife reads this (not a chance) -- they'd make great stocking stuffers.