#!/bin/bash
db=/var/db/co2mon/graph.rrd
[ -e "$db" ] || rrdtool create "$db" --step 5 \
	DS:CO2:GAUGE:60:0:3000 \
	DS:TEMP:GAUGE:60:0:40 \
	RRA:AVERAGE:0:1:17280 \
	RRA:AVERAGE:0.5:12:43200

last_co2=U
last_temp=U

update_rrd() {
    rrdtool update "$db" --template CO2:TEMP -- N:$last_co2:$last_temp
}

co2mond | while read -r name value; do
    echo "$name $value"
    if [ "$name" == "CntR" ]; then
        last_co2=$value
        update_rrd
    elif [ "$name" == "Tamb" ]; then
        last_temp=$value
        update_rrd
    fi
done