Enabling 3x CT for basic energy monitor (Heatpump Monitor)

I’m planing to use the Heatpump board without MBUS support as a cheap EmonTx + EmonBase.

I am half way through assembling and starting to look at the Arduino code. Correct me if I am wrong but my interpretation is that only two CT’s are configured in the ATmega software currently ? I haven’t actually flashed the firmware yet, so I could be way off the mark.

If I am right, do I just need to copy / paste / tweak to include the third CT ? Apart from the ATmega, are there any other places in code that I need to fix in order to enable the third CT ?


With further digging it looks like CT3 shares ADC3 (ATMega pin 26) with Grundfoss Flow sensor input. A solder bridge needs to be made on the board to connect CT3. https://github.com/openenergymonitor/HeatpumpMonitor/tree/master/Hardware/v4