Non compliance with metering specification

[asbachb]

Problem

I'm currently developing a metering device to track gas consumption. After some testing I recognized that the values represented in Home Assistant does not match with my cluster configuration as it's missing the decimal places. After some research it seems that zha does not respect the SummationFormatting which is a required attribute according to the spec. (see Table 10-71, Line 16687, Page 10-116, ZigBee Cluster Library Specification Revision 8)

So the main problem is that currently the only way to have correct readings from zha would be provide the Divisor attribute. So actually it's currently not possible for a meter which is compliant to the spec to show a correct reading in Home Assistant.

More Context

When you implement the metering cluster you are required to provide at least following attributes:

CurrentSummationDelivered

CurrentSummationDelivered represents the most recent summed value of Energy, Gas, or Water delivered and consumed in the premises. CurrentSummationDelivered is mandatory and must be provided as part of the minimum data set to be provided by the metering device. CurrentSummationDelivered is updated continu16315 ously as new measurements are made.

Status

The Status attribute provides indicators reflecting the current error conditions found by the metering device.

UnitofMeasure

UnitofMeasure provides a label for the Energy, Gas, or Water being measured by the metering device

SummationFormatting

SummationFormatting provides a method to properly decipher the number of digits and the decimal location of the values found in the Summation Information Set of attributes.

MeteringDeviceType

MeteringDeviceType provides a label for identifying the type of metering device present.

References

• ZigBee Cluster Library Specification Revision 8
• [BUG] INNR SP 240 "summation delivered" kWh value is 100x expected value zha-device-handlers#2781

CC

@TheJulianJES