Want to time status periods on an input

I want to be able to time the period (typically greater than 10mS) that an input is ON.

Stage 1 - Specifically I want to determine the pulse rate in mS or seconds from the led on the front of a electrical power consumption utility meter which typically flashed once for each Watt/Hour of consumption & then display the value on the serial monitor. Needs to be interupt driven.

Stage 2 would then use something like 433MHz radio link modules to send the data to a host display controller where it displays the instantaneously power consumption at any time.

Stage 3 - Data logging to SD card

Anyone done similar before?

Anyone done similar before?

Yes, you should have a look in the home automation section - http://arduino.cc/forum/index.php/board,16.0.html - There are many similar projects discussed (and others too)

For anyone following this topic - I found this excellent link below http://www.airsensor.co.uk/component/zoo/item/energy-monitor.html