My Heatpump App: How to configure two SDM120s inputs for the heatpump_elec feed?

[teepbee (Tim)]

I am happily receiving data from two SDM120s which are monitoring the internal and external units of a Daikin Altherma HT Split ASHP via an emonPi.

Emoncms is self-hosted and currently running 11.3.0.

I have searched the docs and community posts and have so far failed to find an example or understand how the two inputs should be configured to achieve the desired result of the single heatpump_elec feed for use in the My Heatpump app.

Looking at the emonhub log it looks like the values from the two SDM 120s are sent in the same message to emoncms. So if I used the +input to process the internal unit value and refer to the external unit value would this sum the two values just received from the same message?

The +input description however says ‘Adds the current value with the last value from other input as selected from the input list.’ which suggests to me it would use the previously received external unit value and not the one received in the same message as the current internal unit value.

Any suggestions would be appreciated.

[Robert.Wall]

@teepbee

The +input description however says ‘Adds the current value with the last value from other input as selected from the input list.’ which suggests to me it would use the previously received external unit value and not the one received in the same message as the current internal unit value.

This depends on which input you put the maths in. If both values arrive in the same message, the highest on the inputs page is processed first, so the addition needs to go in the second one.

[teepbee (Tim)]

@Robert.Wall Thanks for the suggestion. Will give that a go.