Today we will examine the mbed NXP LPC1768 development board. The goal of the mbed system is to “provide(s) a platform for microcontroller hardware, tools, libraries and resources designed to enable rapid prototyping with microcontrollers.” (http://mbed.org/handbook/About). Personally I also see this as a good option for a “next step” for those who have outgrown their Arduino – the mbed offers much more processing power, a similar development environment and similar hardware ease of use. A great way to move from 8-bit to 32-bit power...
The NXP LCP1768 MCU on our mbed board offers the following specifications:
− a Cortex-M3 core running at 96MHz
− 512kb flash memory and 64kb RAM
− powered via USB or 4.5~9V DC applied straight to the board
− Real time clock (requires external battery backup if necessary)
Loads of I/O options, including:
− USB serial
− Ethernet on board
− serial I/O
− Control-area network (CAN) bus
− 3.3v digital logic, 40mA per digital pin with a total maximum of 400 mA
− analog and digital I/O pins
For a full description and data sheet, please visit: http://mbed.org/handbook/mbed-NXP-LPC1768.
Although a small project started by two ARM employees, the mbed has proven to be a worthy product to allow people of generally all skill levels access to powerful microcontrollers without a lot of the inherent complications. It does this in two ways:
Firstly, the hardware is very simple and designed for ease of use. The LPC1768 is mounted on a small board to convert it to a DIP format, making breadboard easy. The designers have also thought to include four blue LEDs for digital output and a nice large reset button. Interface with the PC is via USB. The mbed appears as a USB flash drive to your computer's operating system, and compiled programs are downloaded as a single .bin file into the mbed.
Secondly, the development environment. Unlike other MCU products on the market, mbed is a completely online development environment. That is, in a manner very similar to cloud computing services such as Google Docs or Zoho Office. However there are some pros and cons of this method. The pros include not having to install any software on the PC – as long as you have a web browser and a USB port you should be fine; any new libraries or IDE updates are handled on the server leaving you to not worry about staying up to date; and the online environment can monitor and update your MCU firmware if necessary. However the cons are that you cannot work with your code off-line, and there may be some possible privacy issues. We will examine the online environment later on.
Preparing and using the mbed is incredibly simple. The designers have certainly exceeded their goal of providing a rapid prototyping environment. The process from opening the box to running your first program is (as always) quite simple.