TCRT5000 holder for Apator G4 gasmeter

A simple holder that keeps a TCRT5000 infrared sensor at the right spot above the right-most number wheel of an Apator G4 gasmeter. The “6” on that wheel has a small mirror which allows detecting it via the IR sensor, which in turn can be read by e.g. an esp32 or esp8266 to allow gas usage monitoring in your smarthome. I've got it running with esphome to visualise gas usage as part of our Home Assistant energy dashboard. The TCRT5000 module gets held in place via a M3 12mm screw, the whole holder can be strapped to the gas meter with a rubber band. In some cases it makes finding the right setting for the module easier to add a small piece of foam over the 2 diodes, to decrease the chance of light leaking into the receiver. 

Yes, the Apator G4 has a reed sensor slot, but depending on your local regulations it might become an issue to remove the cover, as it can only be removed in a destructive way. The IR sensor approach is completely removable and doesn't require any actual change to the gas meter itself.