* PowerMeter: gracefully handle non-float MQTT values
* PowerMeter: update _lastPowerMeterUpdate conservatively
update the timestampt only if the topic actually matched any
subscription and if the value could be parsed as a float.
* PowerMeter: unsubscribe before subscribing
* PowerMeter: organize subscriptions in a map
this allows for a slightly more elegant code and reduced amount of code
overall.
* PowerMeter: clean up header
* move private methods to private section of class declaration.
* remove unused member variable.
* DPL: implement verbose logging switch
* MQTT: implement verbose logging switch
* power meter: implement verbose logging switch
* Hoymiles lib: implement verbose logging switch
* cpp linting: "final" makes "virtual" and "override" redundant
... however, using only "final" is not as verbose.
In addition to the cyclic query of the power meters, they will be queried on demand when total power is requested and last update is older than 1 second.
* add support for energy & power readings on SML based power meters, taking OBIS 16.7.1 for power (using mod. SML Parser lib. by olliiiver)
* switched SML read to use software serial
* made total power meter response controled by meter source to obtain either the sum of phase powers or explicit total power provided by meter
* made mqtt subscriptions to power meter topics meter source dependend
* simplified SML read loop and OBIS handler registration, + minor refactoring
* minor cleanup/style changes and optim. PowerMeter
* fixed build, add SOURCE_SML == 4
* removed optional usage of HW serial for SML power meter
* switched to usage of _powerMeter1Power for SML power reading to allign better with existing code
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Co-authored-by: helgeerbe <helge@erbehome.de>
