The mbed Microcontroller

The mbed Microcontroller is a 32-bit ARM processor with a comprehensive set of peripherals and a built-in USB interface, all provided in a small and practical DIP package.

My NXP LPC1768


This mbed Microcontroller is based on a Cortex-M3 Core running at 96MHz, with 512KB FLASH, 64KB RAM and a load of interfaces including Ethernet, USB Device, CAN, SPI, I2C and other I/O.


  • 40-pin DIP package
  • 0.1. pitch, 0.9. pin spacing
  • 54mm x 26mm


  • Powered by USB or 4.5v – 9.0v appiled to VIN
  • <200mA (100mA with Ethernet disabled)
  • Real-time clock battery backup input VB
  • 1.8v – 3.3v Keeps Real-time clock running
  • Requires 27uA, can be supplied by a coin cell
  • 3.3v regulated output on VOUT to power peripherals
  • 5.0v from USB available on VU (only available when USB is connected!)
  • Current limited to 500mA
  • Digital IO pins are 3.3v, 40mA each, 400mA max total


  • Vin – External Power supply to the board
    • 4.5v-9v, 100mA + external circuits powered through the Microcontroller
  • Vb – Battery backup input for Real Time Clock
    • 1.8v-3.3v, 30uA
  • nR – Active-low reset pin with identical functionality to the reset button.
  • Pull up resistor is on the board, so it can be driven with an open collector
  • IF+/- – Reserved for Future use

This is my mbed attached to a development board.

My mbed development board. Provides USB interface, ethernet connectivity and a micro SD card

So far, I have programmed my mbed to…

  • Send a tweet to twitter (See
  • Act as a VT100 terminal (Only sent data to my Mac so far)
  • 16×2 LCD panel clock

I will upload some more photos soon, and possibly some video.

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