Im pleased to say that we’ve found the main issue with @richardsmith99’s MBUS reader. It turns out that the new programmer in the shop has it’s orientation flipped, and the picture of the programmer in the guide shows the SMT components on the top, whilst with the new programmer the SMT components should be on the underside. The main issue being that I had not put a GND label on the MBUS reader board to indicate the right connection orientation.
This is what the orientation should be for the new programmer:
After that I needed to update the emonhub MBUS interfacer to expand the variable types it supported. I have written the MBUS interfacer as a relatively minimal implementation of a full mbus decoder without needed external dependencies.
Using rSCADA - Raditex control systems and GitHub - ganehag/pyMeterBus: Pure Python implementation of the Meter-Bus (M-Bus EN13757-3) protocol. I cross check what the full set of readings should be for a given attached MBUS meter and then add the required fields to the emonhub MBUS interfacer.
Im not 100% sure that this is the right approach in the long term. It may be better to just use the pyMeterBus library and have full frame decoding support. Something I may revisit.
The EmonHub MBUS interfacer now supports reading the following values from the Sharky 775:
- Cumulative Energy in kWh
- Cumulative Volume in m3
- Power in Watts
- Flow temperature in Celsius
- Return temperature in Celsius
- DeltaT in Kelvin
Flow rate is also available but I haven’t quite managed to decode this one properly yet.