Using EmonTH Sensors on another RPi

I currently use 4 EmonTH sensors on my EmonPi and I use mqtt to send that temperature/humidity data to another Raspberry PI which is my heating controller. I would like to ‘read’ the sensor data directly into the Heating RPi without having to mqtt it from the EmonPi.

I am not an expert in this subject. What hardware do I need to add and is there any special considerations vis-a-vis reading the sensor data directly into the Heating RPi?

Thank you

The data from the EmonTHs is sent by RF and received by the RF chip in the emonPi. The only way of doing what you suggest is to add an RF receiver to the other Pi and add in some software to read that data. You will likely end up transferring it via MQTT anyway.

Why do you need to change the setup?

I see a problem with adding a receiver IF Neil is using LPL and IF the emonTH asks for an acknowledgment. If it does both, both emonBases will acknowledge at the same time, jam each other and the emonTH will retransmit because it didn’t receive the acknowledgment. And this is likely to happen every minute and rapidly drain the batteries.

It won’t happen with JeeLib or my rfm69TxLib or rfm69nTxLib.

Thank you for the response and sorry for my delay. I have a RPi that I use to control a 3 zone heating/cooling system and currently I do use mqtt to send sensor data from the EmonPi. This method works fine but is not the most robust setup as the H/C Rpi relies on the operation of the EmonPi. Thats why I want to read the sensor data directly into the H/C RPi.

I like the wireless sensors for ease of installation and replacement in case of failure. If it’s not possible I can always used wired sensors but this obviously will require some expense as it’s quite a large space. Living in the US Northeast, sustained heating failure is not an option.


Neil Hastings
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