Reading PWM with pins other than CAP

Development Boards MicroMod
1

Before I’ve used CAP pins to capture PWM values. I’m in a position now where I may need to use some other type of GPIO pin to do that job.

Without getting into too much detail, one option I have is to use the LPC1768 blueboard to read 8 PWM values, and write these out to serial. This all the processor has to do, and it has 8 CAP pins, but they are not all pinned out. So I could:

  1. Solder wire wrap to the pin(s) I need access to.

  2. Use GPIOs in a way new to me in order to detect and time the edges.

I expect the 8 PWMs to be coming in at 40Hz, and to be from 1000-2000microsec long. These should be assumed to be asynchronous. I would like 1 micro second resolution.

Another board I could possibly use is the Sparkfun data logger. I may be able to use it’s extra pins to do this.