Part 2a: The Sensor Bar (Arduino Gas Meter project)


Ok, so here we are a few days later than expected. I’ve been a bit too busy to tinker lately, but I’ve made some interesting progress. I’ll keep this post brief…

Firstly, the phototransistor I ordered from Maplin turned out to be of limited use since it’s ‘detection range’ is a little bit too small to work with the gas meter properly. Also, due to the siting of the gas meter within my property (in a cupboard, with a chair in front of it!), I needed the sensor to be remote to the Arduino. So I ordered a Fairchild Photoreflector from Active Robots. On the surface, it’s everything I need (a photoreflector with wires already attached). Very inexpensive.

Fairchild Photoreflector

Simply dropped this right in place of the existing photoreflector and it works a treat.

Experiments with mounting the sensor to the gas meter

So far, having attempted to mount the sensor on a little bracket in front of the meter, I can’t get an accurate reflection (annoyingly there is a clear plastic cover over the reflective disc which is at a 45 degree angle – sort of – and curved). Having run out of Blu-tac on a previous tinkering experiment, I’ll have to go get some more tomorrow in order to experiment with that.

Reading the meter

I just got my hands on a Nuelectronics LCD Shield so I’ll be setting that up soon to display the meter value.

More to follow soon…