gmd

#!/bin/bash

# Added to GIThub https://github.com/viper0131/gasmeter

# Our lamps:
#	(These are wiringPi pin numbers)
green=7

# The input sensors
sensor=2

COUNTER=0
PREV_COUNTER=0
DATADIR="/var/lib/gasmeter"
COUNTERDATA="$DATADIR/counter"
DB_COUNTER="$DATADIR/gm-counter.rrd"
DB_COUNTER="$DATADIR/gm-counter-highres.rrd"
DB_FLOW="$DATADIR/gm-flow.rrd"
DB_FLOW_HIGHRES="$DATADIR/gm-flow-highres.rrd"

LOGFILE="/var/log/gasmeter.log"
TICKDATE=0
PREV_TICKDATE=0
TICK_SIZE=10 # each tick is 10L gas

FLOW=0
FLOW2=0

# setup:
#	Program the GPIO correctly and initialise the lamps
#######################################################################

setup ()
{
  #set -x

  if [ ! -d "$DATADIR" ]; then
    mkdir -p $DATADIR
  fi
  NOW=$(date +%F\ %T)

  createRRD

  echo "$NOW init: Starting..." >> $LOGFILE
  for i in $green ; do gpio mode $i out ; done
  for i in $green ; do gpio write $i 0 ; done
  gpio mode  $sensor in
 
  if [ ! -f $COUNTERDATA ] ; then
    COUNTER=0
  else
    COUNTER=( $(<$COUNTERDATA) )
  fi
  echo "$NOW init: Counter starts with $COUNTER" >> $LOGFILE
  signalSetup
}

# waitSensor:
#######################################################################

waitSensor ()
{
  TIMER=0
  MAX_TIMER=2200
  RESULT=0

  # echo -n "Waiting for signal ... "
  while [ $TIMER -le $MAX_TIMER ]; do
    RESULT=`gpio read $sensor`
    if [ $RESULT -eq 1 ]; then
      echo "signal received..."
      notifyGreen
      break
    fi
    sleep 0.1
    let TIMER=TIMER+1
  done
  
  return $RESULT
}

signalSetup()
{
  gpio write $green 1
  sleep 0.2
  gpio write $green 0
  sleep 0.1
  gpio write $green 1
  sleep 0.2
  gpio write $green 0
  sleep 0.1
  gpio write $green 1
  sleep 0.2
  gpio write $green 0
}

blinkGreen()
{
gpio write $green 1
sleep 0.5
gpio write $green 0
}

notifyGreen()
{
  while [ `gpio read $sensor` = 1 ]; do
    gpio write $green 1
    sleep 0.1
  done
  gpio write $green 0
}

calcFlow()
{
  TICKDATE=$(date +%s)
  if [ "$PREV_TICKDATE" -ne 0 ]; then
    let DELTA=TICKDATE-PREV_TICKDATE
    let DELTA_COUNT=COUNTER-PREV_COUNTER
 
    #calc flow in liters/sec 
    e="$DELTA_COUNT * $TICK_SIZE / $DELTA"
    FLOW=$(float_eval "$e")
 
    #kuub / hour
    e="$DELTA_COUNT * $TICK_SIZE / $DELTA * 3.6"
    FLOW2=$(float_eval "$e") 

    #echo "flow (l/s): $FLOW"
    #echo "flow (k/h): $FLOW2"
 
  fi 
  PREV_TICKDATE=$TICKDATE
  PREV_COUNTER=$COUNTER
}

doSomething()
{
  NOW=$(date +%F\ %T)
  FLOW2=0

  if [ $1 -eq 1 ]; then
    let COUNTER=COUNTER+1 
    calcFlow
  fi

  e="$COUNTER / 100"
  value=$(float_eval "$e")
  echo "$NOW, $value" >> $LOGFILE
  echo "$NOW, $value"
  echo $COUNTER > $COUNTERDATA

  updateRRD $value $FLOW2
}

# RRD Tools
#####################################################################
createRRD ()
{
  START=`date --date="\`date +%a\ %b\ %e\ 00:00\`" +%s`

  if [ ! -f $DB_FLOW_HIGHRES ]; then
    echo "Creating $DB_FLOW_HIGHRES..."
    rrdtool create $DB_FLOW_HIGHRES \
    --start $START \
    --step 10 \
    DS:flow:GAUGE:60:0:6 \
    RRA:AVERAGE:0.75:1:535680 \
    RRA:AVERAGE:0.75:12:535680 \
    RRA:AVERAGE:0.75:288:535680 \
    RRA:LAST:0.75:1:1488 \
    RRA:MAX:0.75:12:1488
  fi

  if [ ! -f $DB_FLOW ]; then
    echo "Creating $DB_FLOW..."
    rrdtool create $DB_FLOW \
    --start $START \
    --step 300 \
    DS:flow:GAUGE:600:0:6 \
    RRA:AVERAGE:0.75:1:17856 \
    RRA:AVERAGE:0.75:12:17856 \
    RRA:AVERAGE:0.75:288:17856 \
    RRA:MAX:0.75:12:1488
  fi

  if [ ! -f $DB_COUNTER_HIGHRES ]; then
    echo "Creating $DB_COUNTER_HIGHRES..."
    rrdtool create $DB_COUNTER_HIGHRES \
    --start $START \
    --step 10 \
    DS:counter:GAUGE:60:0:99999999 \
    RRA:LAST:0.75:1:535680 \
    RRA:LAST:0.75:12:535680 \
    RRA:LAST:0.75:288:535680
  fi

  if [ ! -f $DB_COUNTER ]; then
    echo "Creating $DB_COUNTER..."
    rrdtool create $DB_COUNTER \
    --start $START \
    --step 300 \
    DS:counter:GAUGE:600:0:99999999 \
    RRA:LAST:0.75:1:17856 \
    RRA:LAST:0.75:12:17856 \
    RRA:LAST:0.75:288:17856
  fi
}

updateRRD()
{
  echo "update RRD ($1, $2)" 
  rrdtool update $DB_COUNTER N:$1
  rrdtool update $DB_COUNTER_HIGHRES N:$1
  if [[ $2 > 0 ]]; then
    rrdtool update $DB_FLOW N:$2
    rrdtool update $DB_FLOW_HIGHRES N:$2
  fi
}

# Floating point number functions.
#####################################################################
# Default scale used by float functions.

float_scale=2

function float_eval()
{
    local stat=0
    local result=0.0
    if [[ $# -gt 0 ]]; then
        result=$(echo "scale=$float_scale; $*" | bc -q 2>/dev/null)
        stat=$?
        if [[ $stat -eq 0  &&  -z "$result" ]]; then stat=1; fi
    fi
    echo $result
    return $stat
}

#######################################################################
# The main program
#	Call our setup routing once, then sit in a loop, waiting for
#	the button to be pressed then executing the sequence.
#######################################################################

setup

#calcFlow
#sleep 1
#calcFlow
#sleep 3
#let COUNTER=COUNTER+100
#calcFlow

while true; do
  waitSensor
  if [ "$?" -eq 1 ]; then 
    #signal detected
    doSomething 1
  else
    #no signal detected, timeout
    echo "Timeout waiting for signal"
    doSomething 0
  fi
  sleep 0.2
done