ESPHome SML library workaround for Holley DTZ541 energy meter

[howeydium]

Hi all together,

please implement a workaround in the ESPHome SML library for the Holley DTZ541 energy meter, which has a faulty SML implementation.

Working workaround:

line 37: https://github.com/volkszaehler/libsml/blob/d65682222dbaddccf4c2c25d4fb530572e60cbd3/sml/src/sml_time.c line 83 https://github.com/volkszaehler/libsml/blob/d65682222dbaddccf4c2c25d4fb530572e60cbd3/sml/src/sml_message.c

Further information about the DTZ541: https://wiki-volkszaehler-org.translate.goog/hardware/channels/meters/power/edl-ehz/holley_dtz541?_x_tr_sl=auto&_x_tr_tl=de&_x_tr_hl=en&_x_tr_pto=wapp

The faulty Holley SML implementation and some workarounds are already discussed and described here: https://github.com/volkszaehler/libsml/issues/75

Without the workaround it is not possible to read any values from the Holley energy meter with an ESP8266 according to https://esphome.io/components/sml.html

Thank you all for all your efforts

Best regards

Howey

[NOYB4Europe]

https://meinzaehler.com/help.html says : - Holley DTZ541-ZDBA Achtung: Ab Version 2.0 (ab Baujahr ca. 2020) werden brauchbare Daten erst nach Freischaltung auf "Info on" bereitgestellt. Werte für Spannung, Strom und Frequenz werden ab Version 2.0 nicht mehr an der Schnittstelle ausgegeben!

It is not working at all, because you need to press "info on" first

[bjoernmayer]

Looking at the code, I'd assume that the checksum calculation with KERMIN shouldn't be an issue: https://github.com/esphome/esphome/blob/dev/esphome/components/sml/sml.cpp#L112

It just never succeeds because of the missing bytes

[Pixelschleuder]

Are there any news here?