counting impulses from an LED

["Marc Gerges" <marc.gerges@xxxxxxxxx>]

Good evening everybody --

My problem is this: there's a pulsing LED on my power meter that I'd
like to use to track my electricity usage. The LED pulses 500 times per
kWh usage, that translates to a pulse every 20s in normal times, but
could go up to a pulse a second.

I can do some soldering off a diagram and I do use a 1-wire bus to
measure other stuff (Linux computer running 24/7 taking regular samples
from some DS1820 temp sensors), but am very much not into hardware.
What would be the easiest way to capture those pulses? 1-wire is
preferred, but I'm happy with a serial connection, too.

Thanks for suggestions!

Marc