I finally managed getting the power values out of my Smart Meter ISKRA MT681 and I want to share my configuration with you. Unfortunately, Home Assistant isn’t supporting SML natively, so I had to build my solution on my own.
This project is also available on GitHub: https://github.com/Moneybox76/HomeAssistant_SML_ISKRA_MT681
First of all I want to say thanks to Stefan Weigert who wrote a really good article (http://www.stefan-weigert.de/php_loader/sml.php) about the implementation of SML and example python scripts. This gave me enough insights in the structure of SML and so finally I was able to modify his script to work with ISKRA MT681. Also I added mqtt support to the script, so I’m able to get the power values easy in Home Assistant, without using the command_line sensor.
Here are my steps getting this running:
-
Connecting my USB Infrared Sensor from volkszaehler (https://wiki.volkszaehler.org/hardware/controllers/ir-schreib-lesekopf-usb-ausgang) to my Raspberry Pi 4 and following the instructions to set up the serial settings via minicom.
-
Install python pyserial & paho-mqtt
sudo apt install pyserial
sudo pip install paho-mqtt
- Create the python 2 script
vi <PATH>/readSML.py
#!/usr/bin/python
# -*- coding: utf-8 -*-
# USB device
usbdevice = "/dev/ttyUSB0"
# MQTT configuration
mqtt_username = "USERNAME"
mqtt_password = "PASSWORD"
mqtt_server = "HOSTNAME|IP-ADDRESS"
mqtt_server_port = "1883"
import os
import time
import serial
import sys
import json
from threading import Timer
import paho.mqtt.client as mqtt
client = mqtt.Client("SML-python")
client.username_pw_set(username=mqtt_username, password=mqtt_password)
client.connect(mqtt_server, port=mqtt_server_port)
client.loop_start()
time.sleep(4)
mystring = ""
crc16_x25_table = [
0x0000, 0x1189, 0x2312, 0x329B, 0x4624, 0x57AD, 0x6536, 0x74BF,
0x8C48, 0x9DC1, 0xAF5A, 0xBED3, 0xCA6C, 0xDBE5, 0xE97E, 0xF8F7,
0x1081, 0x0108, 0x3393, 0x221A, 0x56A5, 0x472C, 0x75B7, 0x643E,
0x9CC9, 0x8D40, 0xBFDB, 0xAE52, 0xDAED, 0xCB64, 0xF9FF, 0xE876,
0x2102, 0x308B, 0x0210, 0x1399, 0x6726, 0x76AF, 0x4434, 0x55BD,
0xAD4A, 0xBCC3, 0x8E58, 0x9FD1, 0xEB6E, 0xFAE7, 0xC87C, 0xD9F5,
0x3183, 0x200A, 0x1291, 0x0318, 0x77A7, 0x662E, 0x54B5, 0x453C,
0xBDCB, 0xAC42, 0x9ED9, 0x8F50, 0xFBEF, 0xEA66, 0xD8FD, 0xC974,
0x4204, 0x538D, 0x6116, 0x709F, 0x0420, 0x15A9, 0x2732, 0x36BB,
0xCE4C, 0xDFC5, 0xED5E, 0xFCD7, 0x8868, 0x99E1, 0xAB7A, 0xBAF3,
0x5285, 0x430C, 0x7197, 0x601E, 0x14A1, 0x0528, 0x37B3, 0x263A,
0xDECD, 0xCF44, 0xFDDF, 0xEC56, 0x98E9, 0x8960, 0xBBFB, 0xAA72,
0x6306, 0x728F, 0x4014, 0x519D, 0x2522, 0x34AB, 0x0630, 0x17B9,
0xEF4E, 0xFEC7, 0xCC5C, 0xDDD5, 0xA96A, 0xB8E3, 0x8A78, 0x9BF1,
0x7387, 0x620E, 0x5095, 0x411C, 0x35A3, 0x242A, 0x16B1, 0x0738,
0xFFCF, 0xEE46, 0xDCDD, 0xCD54, 0xB9EB, 0xA862, 0x9AF9, 0x8B70,
0x8408, 0x9581, 0xA71A, 0xB693, 0xC22C, 0xD3A5, 0xE13E, 0xF0B7,
0x0840, 0x19C9, 0x2B52, 0x3ADB, 0x4E64, 0x5FED, 0x6D76, 0x7CFF,
0x9489, 0x8500, 0xB79B, 0xA612, 0xD2AD, 0xC324, 0xF1BF, 0xE036,
0x18C1, 0x0948, 0x3BD3, 0x2A5A, 0x5EE5, 0x4F6C, 0x7DF7, 0x6C7E,
0xA50A, 0xB483, 0x8618, 0x9791, 0xE32E, 0xF2A7, 0xC03C, 0xD1B5,
0x2942, 0x38CB, 0x0A50, 0x1BD9, 0x6F66, 0x7EEF, 0x4C74, 0x5DFD,
0xB58B, 0xA402, 0x9699, 0x8710, 0xF3AF, 0xE226, 0xD0BD, 0xC134,
0x39C3, 0x284A, 0x1AD1, 0x0B58, 0x7FE7, 0x6E6E, 0x5CF5, 0x4D7C,
0xC60C, 0xD785, 0xE51E, 0xF497, 0x8028, 0x91A1, 0xA33A, 0xB2B3,
0x4A44, 0x5BCD, 0x6956, 0x78DF, 0x0C60, 0x1DE9, 0x2F72, 0x3EFB,
0xD68D, 0xC704, 0xF59F, 0xE416, 0x90A9, 0x8120, 0xB3BB, 0xA232,
0x5AC5, 0x4B4C, 0x79D7, 0x685E, 0x1CE1, 0x0D68, 0x3FF3, 0x2E7A,
0xE70E, 0xF687, 0xC41C, 0xD595, 0xA12A, 0xB0A3, 0x8238, 0x93B1,
0x6B46, 0x7ACF, 0x4854, 0x59DD, 0x2D62, 0x3CEB, 0x0E70, 0x1FF9,
0xF78F, 0xE606, 0xD49D, 0xC514, 0xB1AB, 0xA022, 0x92B9, 0x8330,
0x7BC7, 0x6A4E, 0x58D5, 0x495C, 0x3DE3, 0x2C6A, 0x1EF1, 0x0F78]
class Watchdog_timer:
def __init__(self, timeout, userHandler=None):
self.timeout = timeout
self.handler = userHandler if userHandler is not None else self.defaultHandler
self.timer = Timer(self.timeout, self.handler)
self.timer.start()
def reset(self):
self.timer.cancel()
self.timer = Timer(self.timeout, self.handler)
self.timer.start()
def stop(self):
self.timer.cancel()
def defaultHandler(self):
raise self
def crc16_x25(Buffer):
crcsum = 0xffff
global crc16_x25_table
for byte in Buffer:
crcsum = crc16_x25_table[(ord(byte) ^ crcsum) & 0xff] ^ (crcsum >> 8 & 0xff)
crcsum ^= 0xffff
return crcsum
def watchdogtimer_ovf():
global mystring
message = mystring[0:-2]
crc_rx = int((mystring[-1] + mystring[-2]).encode('hex'), 16)
crc_calc = crc16_x25(message)
if crc_rx == crc_calc:
if message[0:8] == '\x1b\x1b\x1b\x1b\x01\x01\x01\x01':
watchdog.stop()
Wirkenergie_Summe_T1_T2_Wh = round((int(message[150:158].encode('hex'),16)*0.1),4)
Wirkenergie_Verbrauch_Hochtarif_T1_Wh = round((int(message[174:182].encode('hex'),16)*0.1),4)
Wirkenergie_Verbrauch_Niedertarif_T2_Wh = round((int(message[198:206].encode('hex'),16)*0.1),4)
Momentane_Leistung_Summe_W = (int(message[222:226].encode('hex'),16))
Momentane_Leistung_Phase_L1_W = (int(message[242:246].encode('hex'),16))
Momentane_Leistung_Phase_L2_W = (int(message[262:266].encode('hex'),16))
Momentane_Leistung_Phase_L3_W = (int(message[282:286].encode('hex'),16))
mystring=""
client.publish("sml/ISKRA_MT681/Wirkenergie_Summe_T1_T2_Wh",str(Wirkenergie_Summe_T1_T2_Wh))
client.publish("sml/ISKRA_MT681/Wirkenergie_Verbrauch_Hochtarif_T1_Wh",str(Wirkenergie_Verbrauch_Hochtarif_T1_Wh))
client.publish("sml/ISKRA_MT681/Wirkenergie_Verbrauch_Niedertarif_T2_Wh",str(Wirkenergie_Verbrauch_Niedertarif_T2_Wh))
client.publish("sml/ISKRA_MT681/Momentane_Leistung_Summe_W",str(Momentane_Leistung_Summe_W))
client.publish("sml/ISKRA_MT681/Momentane_Leistung_Phase_L1_W",str(Momentane_Leistung_Phase_L1_W))
client.publish("sml/ISKRA_MT681/Momentane_Leistung_Phase_L2_W",str(Momentane_Leistung_Phase_L2_W))
client.publish("sml/ISKRA_MT681/Momentane_Leistung_Phase_L3_W",str(Momentane_Leistung_Phase_L3_W))
mystring=""
else:
mystring=""
watchdog.stop()
else:
mystring=""
watchdog.stop()
time.sleep(10)
try:
my_tty = serial.Serial(port=usbdevice, baudrate = 9600, parity =serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE, bytesize=serial.EIGHTBITS, timeout=0)
my_tty.close()
my_tty.open()
except Exception, e:
exit()
try:
my_tty.reset_input_buffer()
my_tty.reset_output_buffer()
watchdog = Watchdog_timer(0.1, watchdogtimer_ovf)
watchdog.stop()
while True:
while my_tty.in_waiting > 0:
mystring += my_tty.read()
watchdog.reset()
except KeyboardInterrupt:
my_tty.close()
client.loop_stop()
- Create a linux service for the script and change the path to the script readSML.py
sudo vi /etc/systemd/system/sml.daemon.service
[Unit]
Description=SML parser
After=multi-user.target
[Service]
Type=idle
ExecStart=/usr/bin/python <PATH>/readSML.py
Restart=on-failure
RestartSec=1m
[Install]
WantedBy=multi-user.target
- Active and start daemon
sudo systemctl daemon-reload
sudo systemctl enable sml.daemon.service
sudo systemctl start sml.daemon.service
After that we should see in MQTT data is coming in unter the topic sml/ISKRA_MT681.
- Now I created some Home Assistant MQTT Sensors to get the data into Home Assistant.
sensor:
- platform: mqtt
state_topic: "sml/ISKRA_MT681/Wirkenergie_Summe_T1_T2_Wh"
name: sml_output_wirkenergie_summe_t1_t2_wh
force_update: true
unit_of_measurement: 'Wh'
icon: mdi:flash
device_class: power
- platform: mqtt
state_topic: "sml/ISKRA_MT681/Wirkenergie_Verbrauch_Hochtarif_T1_Wh"
name: sml_output_wirkenergie_verbrauch_hochtarif_t1_wh
force_update: true
unit_of_measurement: 'Wh'
icon: mdi:flash
device_class: power
- platform: mqtt
state_topic: "sml/ISKRA_MT681/Wirkenergie_Verbrauch_Niedertarif_T2_Wh"
name: sml_output_wirkenergie_verbrauch_niedertarif_t2_wh
force_update: true
unit_of_measurement: 'Wh'
icon: mdi:flash
device_class: power
- platform: mqtt
state_topic: "sml/ISKRA_MT681/Momentane_Leistung_Summe_W"
name: sml_output_momentane_leistung_summe_w
force_update: true
unit_of_measurement: 'W'
icon: mdi:flash
device_class: power
- platform: mqtt
state_topic: "sml/ISKRA_MT681/Momentane_Leistung_Phase_L1_W"
name: sml_output_Momentane_leistung_phase_l1_w
force_update: true
unit_of_measurement: 'W'
icon: mdi:flash
device_class: power
- platform: mqtt
state_topic: "sml/ISKRA_MT681/Momentane_Leistung_Phase_L2_W"
name: sml_output_Momentane_leistung_phase_l2_w
force_update: true
unit_of_measurement: 'W'
icon: mdi:flash
device_class: power
- platform: mqtt
state_topic: "sml/ISKRA_MT681/Momentane_Leistung_Phase_L3_W"
name: sml_output_Momentane_leistung_phase_l3_w
force_update: true
unit_of_measurement: 'W'
icon: mdi:flash
device_class: power
- Because the SML messages arrives every 2 - 4 seconds I created filtered sensors with a time throttle. As a result I’m able to define how much data is stored in my database for e.g. Grafana charts.
sensor:
- platform: filter
name: 'sml_output_momentane_leistung_summe_w_filtered'
entity_id: sensor.sml_output_momentane_leistung_summe_w
filters:
- filter: time_throttle
window_size: 00:01:00
precision: 0
- platform: filter
name: 'sml_output_momentane_leistung_phase_l1_w_filtered'
entity_id: sensor.sml_output_momentane_leistung_phase_l1_w
filters:
- filter: time_throttle
window_size: 00:01:00
precision: 0
- platform: filter
name: 'sml_output_momentane_leistung_phase_l2_w_filtered'
entity_id: sensor.sml_output_momentane_leistung_phase_l2_w
filters:
- filter: time_throttle
window_size: 00:01:00
precision: 0
- platform: filter
name: 'sml_output_momentane_leistung_phase_l3_w_filtered'
entity_id: sensor.sml_output_momentane_leistung_phase_l3_w
filters:
- filter: time_throttle
window_size: 00:01:00
precision: 0
- platform: filter
name: 'sml_output_wirkenergie_summe_t1_t2_wh_filtered'
entity_id: sensor.sml_output_wirkenergie_summe_t1_t2_wh
filters:
- filter: time_throttle
window_size: 06:00:00
precision: 1
- platform: filter
name: 'sml_output_wirkenergie_verbrauch_hochtarif_t1_wh_filtered'
entity_id: sensor.sml_output_wirkenergie_verbrauch_hochtarif_t1_wh
filters:
- filter: time_throttle
window_size: 06:00:00
precision: 1
- platform: filter
name: 'sml_output_wirkenergie_verbrauch_niedertarif_t2_wh_filtered'
entity_id: sensor.sml_output_wirkenergie_verbrauch_niedertarif_t2_wh
filters:
- filter: time_throttle
window_size: 06:00:00
precision: 1
- Finally I customized the sensors in my customize.yaml
sensor.sml_output_momentane_leistung_summe_w_filtered:
friendly_name: Momentane Gesamtleistung (W)
icon: mdi:flash
unit_of_measurement: W
device_class: power
sensor.sml_output_momentane_leistung_phase_l1_w_filtered:
friendly_name: Momentane Leistung Phase L1 (W)
icon: mdi:flash
unit_of_measurement: W
device_class: power
sensor.sml_output_momentane_leistung_phase_l2_w_filtered:
friendly_name: Momentane Leistung Phase L2 (W)
icon: mdi:flash
unit_of_measurement: W
device_class: power
sensor.sml_output_momentane_leistung_phase_l3_w_filtered:
friendly_name: Momentane Leistung Phase L3 (W)
icon: mdi:flash
unit_of_measurement: W
device_class: power
sensor.sml_output_wirkenergie_summe_t1_t2_wh_filtered:
friendly_name: Gesamtverbrauch Wirkenergie T1 + T2 (Wh)
icon: mdi:flash
unit_of_measurement: Wh
device_class: power
sensor.sml_output_wirkenergie_verbrauch_hochtarif_t1_wh_filtered:
friendly_name: Verbrauch Wirkenergie Hochtarif T1 (Wh)
icon: mdi:flash
unit_of_measurement: Wh
device_class: power
sensor.sml_output_wirkenergie_verbrauch_niedertarif_t2_wh_filtered:
friendly_name: Verbrauch Wirkenergie Niedertarif T2 (Wh)
icon: mdi:flash
unit_of_measurement: Wh
device_class: power
I think that’s all I did to get this running. Obviously you must have python 2 available on your host system.
Hopefully this is valuable to someone of you,
Michael
