Lpc2000

Hi J,

> Does anyone have any code examples of how I can use a LPC2138 to detect
> the width of the positive pulse in a PWM signal. I know I can use the
> timer circuit and detect the rising and falling edges do some math and
> determine the width. I am very new to micro controllers and some code
> examples or guidance would be greatly appreciated.

For some theory take a look at this Atmel application note:
AVR135: Using Timer Capture to Measure PWM Duty Cycle   (12 pages, revision
A, updated 10/05)
Found here: http://www.atmel.com/dyn/products/app_notes.asp?family_id=607

As for the LPC2100 you would use the Capture feature of the Timer
peripheral.  Setup timer to generate an interrupt on capture pin leading or
trailing edge.  In the interrupt routine read the capture register value and
pass it on to your algorithm.  

Be sure to read the correct section of the errata sheet related to TIMER.
 

Joel