We’re using Tasmota’s smart meter interface on an ESP8266 (D1 Mini) to read out values from our electricity meters (Iskra MT 174 and DZG DWS7420.1.G2) through the optical ports using a read head.
Clone git@github.com:arendst/Tasmota.git.
Open with VSCode, PlatformIO needs to be installed.
In the bottom bar, click on the button for Switch PlatformIO Platform Environment and select env:tasmota.
Under /tasmota, create a file user_config_override.h if that doesn’t exist already.
Paste the following into that file, right before the final #endif:
#ifndef USE_SCRIPT
#define USE_SCRIPT
#endif
#ifndef USE_SML_M
#define USE_SML_M
#endif
#ifdef USE_RULES
#undef USE_RULES
#endif
Connect the ESP via USB and click PlatformIO: Build, Upload and Monitor in the bottom bar. Once the upload is finished, close the terminal.
Connect the device to WiFi, either by connecting to the temporary AP or using the Tasmota web installer.
Make note of the IP address (10.0.0.240) and visit the web interface.
Under Configuration and Configure Module, set Module type to Generic (0) and make sure that all GPIOs are set to None (you may need to first save and reboot).
Under Configuration and MQTT, connect to the MQTT server (cf. VMs/Home Assistant). Use tasmota_smart_meter as the topic.
Under Configuration and Other, set Device Name to tasmota-smart-meter and Friendly Name 1 to Tasmota Smart Meter.
Under Tools and Console, run SetOption19 0 to enable native discovery for Home Assistant. Further, run TelePeriod 30 to transmit values over MQTT every 30 seconds.
Connect the two read heads to the ESP:
| Meter | Pin read head | Pin ESP |
|---|---|---|
| both | VBUS | 3V3 |
| both | GND | GND |
| Iskra | RX | D1 (GPIO5) |
| Iskra | TX | D2 (GPIO4) |
| DZG | RX | D5 (GPIO14) |
| DZG | TX | D6 (GPIO12) |
In the web interface, under Tools and Edit script, select Script enable, then paste the following script:
>D
res=0
scnt=0
>B
->sensor53 r
->sensor53 d0
;For this Example in the >F section
>F
;count 100ms
scnt+=1
switch scnt
case 6
;set sml driver to 300 baud and send /?! as HEX to trigger the Meter
res=sml(1 0 300)
res=sml(1 1 "2F3F210D0A")
;1800ms later \> Send ACK and ask for switching to 9600 baud
case 18
res=sml(1 1 "063035300D0A")
;2000ms later \> Switching sml driver to 9600 baud
case 20
res=sml(1 0 9600)
;Restart sequence after 50x100ms
case 500
; 5000ms later \> restart sequence
scnt=0
ends
>M 2
; original: +1,5,o,0,9600,Iskra,4
+1,5,o,16,9600,Iskra,4
1,1-0:1.8.0*255(@1,Bezug gesamt,kWh,bezug_gesamt,3
1,1-0:2.8.0*255(@1,Einspeisung gesamt,kWh,einspeisung_gesamt,3
1,1-0:1.7.0*255(@1,Bezug aktuell,kW,bezug_aktuell,3
1,1-0:2.7.0*255(@1,Einspeisung aktuell,kW,einspeisung_aktuell,3
+2,14,s,16,9600,DZG
2,77070100010800ff@1000,Erzeugung gesamt,kWh,erzeugung_gesamt,4
2,77070100100700ff@1000,Erzeugung aktuell,kW,momentane_wirkleistung,4
#
problem: https://github.com/home-assistant/core/issues/104305
in customize.yaml:
# Benni (2024-04-13): Changes necessary for tasmota-smart-meter sensor to have correct attributes (see Hardware/Tasmota smart meter).
# Note: We are not touching the *_gesamt sensors here. For those, we have template sensors in configuration.yaml that filter out 0 values.
sensor.tasmota_smart_meter_iskra_bezug_aktuell:
device_class: power
state_class: measurement
unit_of_measurement: kW
sensor.tasmota_smart_meter_iskra_einspeisung_aktuell:
device_class: power
state_class: measurement
unit_of_measurement: kW
sensor.tasmota_smart_meter_dzg_erzeugung_aktuell:
device_class: power
state_class: measurement
unit_of_measurement: kW
in /homeassistant/configuration.yaml:
# Benni (2024-04-14): tasmota-smart-meter will sometimes (at boot?) send out 0 values, which cause the energy dashboard
# to hallucinate a doubling in the energy usage. Workaround taken from: https://community.home-assistant.io/t/filter-0-values-from-total-enery/503848/2
template:
- sensor:
- name: "Bezug gesamt"
unit_of_measurement: kWh
state: >
{% set state1 = states('sensor.tasmota_smart_meter_iskra_bezug_gesamt')|float(none) %}
{% if state1 > 0 %}
{{ state1 }}
{% endif %}
device_class: energy
state_class: total_increasing
unique_id: iskra_bezug_gesamt
availability: >
{{ state1 != none }}
- name: "Einspeisung gesamt"
unit_of_measurement: kWh
state: >
{% set state2 = states('sensor.tasmota_smart_meter_iskra_einspeisung_gesamt')|float(none) %}
{% if state2 > 0 %}
{{ state2 }}
{% endif %}
device_class: energy
state_class: total_increasing
unique_id: iskra_einspeisung_gesamt
availability: >
{{ state2 != none }}
- name: "Erzeugung gesamt"
unit_of_measurement: kWh
state: >
{% set state3 = states('sensor.tasmota_smart_meter_dzg_erzeugung_gesamt')|float(none) %}
{% if state3 > 0 %}
{{ state3 }}
{% endif %}
device_class: energy
state_class: total_increasing
unique_id: dzg_erzeugung_gesamt
availability: >
{{ state3 != none }}