Volkszähler

• https://www.volkszaehler.org/
• https://wiki.volkszaehler.org/software/releases/start
• https://wiki.volkszaehler.org/howto/raspberry_pi_image
• https://wiki.volkszaehler.org/hardware/channels/meters/power/edl-ehz/edl21-ehz
• https://wiki.volkszaehler.org/hardware/controllers/ir-schreib-lesekopf?s[]=ir&s[]=lesekopf
• https://wiki.volkszaehler.org/hardware/controllers/ir-schreib-lesekopf-usb-ausgang

Install desktop

If you'd like to have the desktop configuration for the raspberry that you configured using the Volkzsähler image you can install the desktop with:

sudo apt-get install raspberrypi-ui-mods -y
sudo raspi-config # activate desktop via menu

Test USB S0 reader

= Prerequsite

you need to install bc for the readmeter script to work

apt-get install bc

=== readmeter bash script ===
#!/bin/bash
# read and evaluate SML output received from EMH eHZ

getmeter() {
  # set serial device
  INPUT_DEV="/dev/ttyUSB0"

  #set $INPUT_DEV to 9600 8N1
  stty -F $INPUT_DEV 1:0:8bd:0:3:1c:7f:15:4:5:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0

  SML_START_SEQUENCE="1B1B1B1B0101010176"
  METER_OUTPUT__START_SEQUENCE=""

  while [ "$METER_OUTPUT__START_SEQUENCE" != "$SML_START_SEQUENCE" ]
  do
    METER_OUTPUT=`cat $INPUT_DEV 2>/dev/null | xxd -p -u -l 460 | tr -d '[:space:]'`
    METER_OUTPUT__START_SEQUENCE=$(echo "${METER_OUTPUT:0:18}")
    if [ "$METER_OUTPUT__START_SEQUENCE" != "$SML_START_SEQUENCE" ];
    then
      echo "missed start and trying again..."
      sleep 0.1
      #exit 1 
    fi
  done

  echo $METER_OUTPUT
}

# 
# match
#  1: prefix
#  2: text
#  3: ofs
#  4: len
#
matchvalue() {
  local l_prefix="$1"
  local l_text="$2"
  local l_ofs="$3"
  local l_len="$4"
  local l_prefix_len=${#l_prefix}
  local l_text_len=${#l_text}
  local l_start=0
  let l_max=l_text_len-l_prefix_len
  #echo  "$l_prefix_len - $l_text_len - $l_max"
  while [ $l_start -lt $l_max ]
  do
    l_part=${l_text:$l_start:$l_prefix_len}
    if [ "$l_prefix" = "$l_part" ]
    then
      let l_start=l_start+l_prefix_len+l_ofs
      local l_value_hex=${l_text:$l_start:$l_len}
      let l_value=0x${l_value_hex}
      # uncomment to debug - but then do not use bc below
      # echo ${l_start}
      # echo ${l_value_hex}
      echo $l_value
      return 
    fi
    let l_start=l_start+1
  done
}

#
# get a value from the SML Sequence
#
getvalue() {
  local l_prefix="$1"
  local l_text="$2"
  local l_ofs="$3"
  local l_len="$4"
  local l_factor="$5"
  local l_title="$6"
  local l_unit="$7"
  #echo "ofs:$l_ofs len: $l_len factor: $l_factor"
  METER_180=$(matchvalue "$l_prefix" "$l_text" "$l_ofs" "$l_len")
  #echo $METER_180
  VALUE=$(echo "scale=2; $METER_180 / $l_factor" |bc)
  echo "$l_title" $VALUE "$l_unit"
}

echo "SML SEQUENCE:"
getmeter
getvalue "77070100010800FF" "$METER_OUTPUT" 20 10 10000 "Meter 1.8.0 (from plant):" "kWh"
getvalue "77070100020800FF" "$METER_OUTPUT" 20 10 10000 "Meter 2.8.0 (  to plant):" "kWh"
#getvalue "77070100010801FF" "$METER_OUTPUT" 20 10 10 "1.8.1"  "kW"
#getvalue "77070100010802FF" "$METER_OUTPUT" 20 10 10 "1.8.2"  "kW"
#getvalue "77070100020801FF" "$METER_OUTPUT" 20 10 10 "2.8.1" "kW" 
#getvalue "77070100020802FF" "$METER_OUTPUT" 20 10 10 "2.8.2" "kW"

Example output

./readmeter 
SML SEQUENCE:
missed start and trying again...
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
Meter 1.8.0 (from plant): 35881.42 kWh
Meter 2.8.0 (  to plant): 15509.69 kWh