Using photo diode to detect light pulses with TTL input module - need a little help

Hi, I'm trying to measure the power consumption of our house. The meter from the gas & electricity company has a LED that flashes one time per 2Wh hour used. (a std. red LED).
I will count each blink using a PC that has a 16 input/output TTL module attached.
I guess I should use a photo diode, but I'm not really sure how to do the wiring. I can use one of the outputs from the TTL module as a +5V power supply.

Any help will be much appreciated.

Thanks!

Br, Bjoern Dirchsen

If you want to read the red LED optically, use a photo darlington (NPN):
Optical - Photo Detectors - Phototransistors | Digi-Key

Connect the emitter to ground and the collector to your TTL input. You also need a pull-up resistor (a big one, 100k and up) from the TTL input to 5V.

Here is a picture: http://www.siriusmicro.com/images/phototransistor-micro.png

Wauw! That was simple!

Let me give a try on monday.

Thanks so much for a fast reply

Br, Bjoern Dirchsen