Initial commit

readSensor

@@ -0,0 +1,89 @@
+#!/bin/bash
+
+#
+# Copyright (c) 2018 leopold@shdx.org
+# Author: Der_Leopold
+#
+# This script tries to read sensor values from a 1wire bus and writes the results
+# and a timestamp to a file. It is intended to be executed periodically, for
+# example via crontab.
+#
+
+# Retry up to n times if the reading fails
+RETRY=3
+
+# Number of seconds to wait between retries
+DELAY=2
+
+# Specify the temperature range where you expect the sensors will be operating
+# This is simply used as a safeguard to detect implausible sensor readings
+MINTEMP=-30
+MAXTEMP=40
+
+# Interface that is connected to the 1wire bus
+USETTY=/dev/ttyUSB0
+
+# Location of the digittemp config file with data about the sensors
+DIGITEMPCONF="/opt/1wire/.digitemprc"
+
+# Command to use for reading the sensors
+CMD="sudo /usr/bin/digitemp_DS9097"
+CMDOPTS=" -q -s $USETTY  -c $DIGITEMPCONF"
+
+# Define sensors that should be queried
+# Format: [<Label>]=<Id>
+declare -A SENSORS=( [0]=LuftTemp [1]=WasserTemp [2]=BodenTemp )
+
+# Location where the readings should be stored
+OUTFILE="output"
+RESULT=""
+
+#
+# no configuration/changes should be necessary below this line
+#
+
+cd "$(dirname "$0")";
+touch "$OUTFILE" 2> /dev/null
+
+if [ ! -w $OUTFILE ]; then
+    echo "Error: output file '$OUTFILE' not writeable"
+    exit 1
+fi
+
+function read_sensor () {
+    OUTPUT=`$CMD $CMDOPTS -t $SENSORID`
+    VALUE=`echo "$OUTPUT" | awk -F "C: " '{print $2}' | awk -F " F:" '{print $1}'`
+    CNT=$(($CNT+1))
+}
+
+function check_output () {
+    if [[ $OUTPUT =~ fail ]] || [[ $OUTPUT =~ owAcquire ]] || [ ${VALUE%.*} -lt $MINTEMP ] || [ ${VALUE%.*} -gt $MAXTEMP ]; then
+        if [ $CNT -le $RETRY ]; then
+            sleep $DELAY
+            read_sensor
+            check_output
+        else
+            RESULT="$RESULT${SENSORS[$SENSORID]}=Error\n"
+        fi
+    fi
+}
+
+function store_result () {
+    RESULT="$RESULT${SENSORS[$SENSORID]}=${VALUE}\n"
+}
+
+function write_to_file () {
+    echo "Timestamp="`date +%s` > "$OUTFILE"
+
+    echo -e "$RESULT" >> "$OUTFILE"
+}
+
+for SENSORID in  "${!SENSORS[@]}"
+do
+    CNT=0
+    read_sensor
+    check_output
+    store_result
+    sleep $DELAY
+done
+write_to_file