Pulse monitor and thermal sensor both with RJ45


I’m trying to install for the first time a bought emonpi-3 (https://openenergymonitor.com/emonpi-3/), I have the pulse detector and the thermal sensor, both have an rj45 connection, (with just 4 and 2 wires connected). and my emonpi has one RJ45 (which I need to use for Ethernet connection to my lan).

how can I simultaneously connect all the three devices (eth, thermometer, pulse)?

Also, the electricity meter is actually located outside my building, and to connect the pulse sensor I’d need to wire it with a longer cable, some 25 additional meters, and would run together with the mains power cable. Is this something that would work? or attenuation/noise would destroy the signal? what options do I have?

This picture shows both ends of your emonPi - look carefully
and you can see your emonPi has TWO RJ45 connectors. One is labelled “Ethernet” and is for an Ethernet connection, the other is labelled “RJ45 I/O” and it is that which you use for the temperature and pulse sensors. You can buy an expander to allow you to connect both sensors at the same time.

Do NOT plug in an Ethernet connection to the I/O port.

I am guessing that you have the Optical pulse sensor. I have not tried to use it with 25 m of cable, but as the output is a voltage level (and not a ‘pulse’ in the strict sense), then you might be able to extend the cable. I think it is something you should try before looking for a more complicated solution.

You can connect the optical pulse sensor to an emonTH - and that would send the pulse count by radio to your emonPi. The emonTH is battery powered and does not have the RJ45 connector, but it does have screw terminals for you to use.

silly me, I hadn’t noticed the second RJ45 connector, sorry about that.

Thanks for the quick reply.