Reed switch and emonPi2

Hi - I have an emonPi2, but the optical pulse counter option will not work with my ancient gas meter (a BK-G4). I have previously used an off the shelf sensor (IN-Z61) with this meter and a separate pulse counter, is it possible to wire the sensor directly into the emonPi2 (I guess across the IRQ and GND)? NB if I could find my IN-Z61 I would just try it, but I need to buy a new one and would like a reality check before shelling out.

Welcome, Robert (not another!) to the OEM forum.

Why not just shell out for a plain reed switch? That’s what I’ve got, wired into an emonTH (but it’s the same input circuit). I needed a capacitor to take out the contact bounce, but the de-bounce software in the emonPi2 should not have a problem with a reed switch.
You do indeed wire it between the pulse input and GND, and use the built-in pull-up.
Check the Docs: Other sensors — OpenEnergyMonitor 0.0.1 documentation for the solder links.


The bare reed switch (no case) is just visible end-on sitting in a groove in the (black) piece of wood. Two screws are terminals, the third upper one secures it all to the meter, which conveniently provided a mounting cut-out ready to accept a switch.

That switch was £0.85 (plus carriage) at the time.