Raspberry PI - CPU temperature rrdtool

cpu_temp_rrdtool.sh

#!/bin/bash -e
command rrdtool || sudo apt-get install rrdtool
command pngquant || sudo apt-get install pngquant

rrdtools_dir=/var/www/html/laravel/public/images/temp-sensor
rrdtools_db=cpu_temp_data.rrd

create(){
  rrdtool create $rrdtools_dir/$rrdtools_db \
    --start now \
    --step 60 \
    --no-overwrite \
    DS:cpu_temp:GAUGE:120:U:U \
    RRA:AVERAGE:0.5:1:525600
}

update_database(){
  READ_TEMP=$(/opt/vc/bin/vcgencmd measure_temp)
  TEMP_VALUE=${READ_TEMP:5:4}
  TIMESTAMP=$(date +%s)
  rrdtool update $rrdtools_dir/$rrdtools_db \
    ${TIMESTAMP}:${TEMP_VALUE}
}

generate_graph(){
  rrdtool graph $rrdtools_dir/cpu_temp_${1}.png \
    --start end-${1} \
    --title "${2} Log" \
    --vertical-label "Temperatura C" \
    --width 1024 \
    --height 576 \
    --color GRID#C2C2D6 \
    --color MGRID#E2E2E6 \
    --dynamic-labels \
    --grid-dash 1:1 \
    --font TITLE:10 \
    --font UNIT:9 \
    --font LEGEND:8 \
    --font AXIS:8 \
    --font WATERMARK:8 \
    --lazy \
    --watermark "$(date -R)" \
    DEF:cpu_temp=$rrdtools_dir/${rrdtools_db}:cpu_temp:AVERAGE \
    AREA:cpu_temp#FF0000AA:"Raspberry Pi CPU Temperatura" \
    LINE1:cpu_temp#FF0000
}

main(){
  [ ! -f "$rrdtools_dir/$rrdtools_db" ] && create
  update_database
  sleep 5
  INDEX=0
  declare -a INTERVALS=("1h" "2h" "6h" "12h" "24h" "1w" "4w" "24w" "1y")
  declare -a TITLES=("1 Hora" "2 Horas" "6 Horas" "12 Horas" "1 Dia" \
    "1 Semana" "1 Mes" "6 Meses" "1 Año")
  ARRAYLENGTH=${#INTERVALS[@]}
  for ((i=1; i<${ARRAYLENGTH}+1; i++))
  do
    generate_graph "${INTERVALS[$i-1]}" "${TITLES[$i-1]}"
  done
  pngquant $rrdtools_dir/*.png --ext .png --force
}

main