Heatpump board RFM12 option?

First can I say the heatpump monitor is an excellent idea! My kit arrived yesterday and I’ve just built it up and got the firmware loaded.

As I already have an emonPi set up and working, I thought the data collected by the heatpump monitor would just automagically appear in the input section of the emonPi. But it doesn’t - help!

I’ve loaded the HeatpumpMonitor_AutoTemp_EmonTx3 Arduino firmare, which has RFM69_ENABLE set to 1. The group and frequency seems to match my emonpi.

Of course it’s possible I’ve just made a mistake in building it - is there an easy way to check that it’s alive and running?

Thanks for any advice…

Hello Evan, the firmware isnt designed to transmit on the RFM69 transceiver, the radio is used for receiving data from EmonTH temperature and humidity nodes.

Do you have the ESP8266 WIFI module soldered? and did you load the EmonESP firmware? The firware is designed for using WIFI for sending data to an EmonPi or emoncms.org

Thanks Trystan,
OK, I had realised that after reading a bit further through the code.

The thing is, the header suggests it does:

// Heatpump monitor example with:
// MBUS meter reader for kampstrup multical 402
// Grundfos vortex flow sensor on analog 0 and 1
// 2x DS18B20 flow + return sensors
// All sending via RFM12/69.

My problem is a big stone wall between the house and where all the heatpump stuff lives, wifi doesn’t go through but emontx does. Anyway I’ll run an Ethernet cable through and buy an access point to go next to this.

I do have the ESP module soldered on, and I’ve looked at the instructions for loading the firmware (brrr). The Arduino IDE is currently failing to download board definitions. One step forwards…


Hello Evan, thanks for spotting that I will amend the description.

Version 1 of the firmware did support this but I disabled it to keep things simple as the intended approach is to use WIFI. You can still access version 1 of the firmware here if you wish to try it:


The main parts for sending data via RFM radio are:

  1. Defining the data structure, see lines 44 to 69.
  2. Assigning sensor readings to the struct properties, e.g line 453
  3. Transmitting the data lines 532 to 544

Excellent, thanks for that Trystan. It’s now talking to the emonPi.

I can see why you’d use the wifi module, and I will come back to that at some point. But apart from the short term problem of getting wifi out there I just couldn’t get the ESP firmware to build :confused: