This is a follow up from my earlier post describing a simple mercury switch connected to an ESP8266 which sends a message to my home server.

I have now installed three of these on the traps around the house. I’m still not quite certain if the battery life is good enough but so far it is. And this morning I got my first actual notification!

This is the trap near the back door. Now there is something odd about this. The first thing to note is that it fired about 3pm. Possums come out at night, not at 3pm. Second is that there are actually three events. I’m not sure why that is. But is isn’t a possum anyway. I checked the trap with some excitement, not having noticed the time. The unit was lying beside the trap which was not fired. It was quite windy yesterday and, though the trap is actually in a sheltered spot, it must have blown off. Or something else disturbed it, maybe a bird or a rat, but probably the wind.

This is how it ought to look. The entry hole is around the other side. But you can see the string loop on this side. If the loop is loose like that the trap is still set.

One of the problems I have with the traps is that sometimes a rat climbs in and trips them. A quick glance from a distance looks like it is still set and it isn’t until some time later when I refresh the baits I find a smelly, decaying rat body. So the alarm should solve that.

I did actually trap a possum last night, but I have 6 traps and 3 alarms. It was in one of the un-alarmed traps. I’d better make some more alarms.