0 Replies Latest reply: Aug 9, 2010 3:57 PM by MrSpoon RSS

mbed NXP LPC1768 Review

MrSpoon

Introduction

IMGP1276.JPGOther reviews have listed the spec’s of the mbed, there’s also plenty of literature provided by NXP. The mbed is a very powerful rapid prototyping tool, built around the NXP LPC1768FBD100,551LPC1768FBD100,551 - a 32 bit swiss-army knife of a microcontroller. This is the mbed’s double-edged sword, complex and powerful applications can be developed in minutes, but such programs are very much prototypes - with no simple path to final product development. NXP are very clear that this platform is for prototypes and educational use only though, and there’s a lot of enjoyment to be had in throwing together something cool.
One of the most distinguishing characteristics of the mbed platform is the use of an online compiler. This sidesteps a lot of the common software and platform dependency issues (see my STM8S review!) and in this reviewer’s opinion is a major step forward, though of course there are detractors. My first use of the compiler in fact was marred with problems, a poor connection led to my being unable to even create a project (eventually I found I’d in fact created dozens). Despite the many claims to the contrary though, it is of course possible to use an offline compiler, at the end of the day the mbed is just a dev board around the LPC1768FBD100,551LPC1768FBD100,551.

Documentation

The mbed platform caters very well to the entry-level market, with a wealth of beginner-friendly documentation on the website. So much so that the documentation can be a little tiresome for those who want ‘just the facts’. There’s even a page that gives an in-depth description of what a breadboard is, which gives a clear idea of just how accessible the mbed is. There’s a good sense of community around the mbed platform, with a community generated ‘cookbook’ containing a lot of info, libraries and example code for using the mbed in a variety of applications and with a growing number of peripherals. Such a sense of community support is probably second only to the Arduino, which takes me to the next section...

Inevitable Comparisons

One of the first questions people asked of the mbed was how it stacked up aganst the Arduino, which is quite an apples and oranges comparison. The Arduino family, being based on relatively underpowered 8 bit microcontrollers, cannot compare to the mbed in terms of features or power. In fact, given the accumulated cost of all those Arduino ‘shields’, and the fact the mbed has so many features built-in, it would probably be cheaper to just get the mbed in many cases. It’s important to remember though, for learners, that the mbed is hugely overpowered for many applications, and being able to develop for the cheapest suitable microcontroller is a valuable skill.

Application

There’s an infinity of cool projects such a powerful device could be used for. The mbed makes it so easy it almost takes all the fun out of it! For an initial test I made a remote control for a Pentax DSLR using an IR led I plucked from an old TV remote. Like most projects, the use of a 32 bit microcontroller for this is ridiculous, but with the mbed I had a working prototype in minutes - so I was able to verify the remote control codes etc - very useful!
As an exercise in just how fun the mbed can be, I added an ethernet jack to the board and had it connected to my router as an embedded server. With the libraries available, this only required a few lines of code! For me, the really exciting aspect of the mbed is that it’s a very easy way to interface any project/circuit to a computer or network. I’ve got a lot of old project ideas which were a little too complex to ever bother implementing - with the mbed I’ll probably have a few of them done by the end of the week!

So do I get one?

The mbed is a little pricey, currently £39 at Farnell. Compared to the Arduino offerings though, this is a great deal and for those considering the Arduino, I’d strongly recommend the mbed in its place. These kinds of devices are great to learn on and a lot of fun to produce cool hacks with. They are not ‘serious’ development platforms though and using third party libraries can only get you so far in life. For beginners on a budget, it’s important to note that you don’t need something like an mbed or an Arduino to learn with, though the level of community of support they have certainly makes them attractive options.
There’s a lot of other things to like about the mbed...It’s a lot smaller than you’d expect, which is a big advantage over the competition. There are a lot of hobbyists who embed Arduinos in projects and given the size difference, the mbed lends itself much more readily to this expensive habit. The mbed comes as a 40 pin DIP package, making it very easy to plug into a breadboard or to attach to a PCB. The mbed is also really powerful, the cookbook even includes synth and graphics libraries, with people already working on demos to show off what the platform can do.
If you have the cash and are currently trying to decide whether to splash out on an mbed, I’d say just do it, you’ll be too busy having fun to regret it.