Thanks for the fresh inspiration. I built something similar for pulse counting the gas meter when the gas utility changed my gasmeter to the odometer type in Nov. 2004.

It worked quite well and I used a small PIC to count the pulses. Unfortunately the photoreflective sensor was not really a permanent fixture and got lost the following summer when we had to shunt stuff around whilst building a house extension.

I’ve now recreated the photoreflective sensor on a small bit of veroboard, which clips to the correct position on the meter with a couple of drilled holes in the veroboard, which are a press-fit over small plastic pegs provided on the meter. There is a cut-away in the plastic underneath the dial where the manufacturer clearly intended to mount their own opto detector unit.

I use an additional transistor to make the sensor more sensitive and I can actually see the various digits go past with a distinctive change in the analogue voltage which it outputs. When the reflective zero goes past the output produces a very distinctive full amplitude pulse.

I now need to couple this into my Arduino and ethernet shield and hope to get the pulse count up to Pachube in a similar way to yourself.

Yes, I have now completed this project. You can read the finished article (with instructions to build your own) at http://blog.richard.parker.name/2009/04/25/how-to-build-a-web-connected-gas-meter-with-your-arduino/

Thanks for stopping by!

Richard.

Nice project – I am looking at doing the same to monitor gas usage – did you get any further than step 2a ?

Drew