w1_poll.sh

#!/bin/bash

# read the w1-temp values
# put each line1 and 2 into variables
# parse and see if it is ready
# if so read the raw value and round it to 2 decimals
read_sensor()
{
    SENSOR_FILE=$1
    local __celsius_raw=$2
    local __celsius_dec=$3
    local __rc=$4

    local indx=0;
    while IFS='' read -r temp; do
        case $indx in
        0) line1=$temp;;
        1) line2=$temp;;
        esac
        indx=$((indx+1))
    done < $SENSOR_FILE

    ready=${line1/YES/,ready}

    if [ "${ready#*,}" == "ready" ] 
    then
        local celsius_raw=${line2#*t=}
        local celsius_dec=$(echo "scale=2; ((${celsius_raw}+5)/1000.0)" | bc)
        eval $__rc="1"
        eval $__celsius_raw="'$celsius_raw'"
        eval $__celsius_dec="'$celsius_dec'"
    else
        eval $__rc="0"
    fi
}

# loop through all the sensors
SENSOR_FILES=$(echo /sys/bus/w1/devices/28-*/w1_slave)

while true; do
    for sensor_file in ${SENSOR_FILES}; do
    read_sensor $sensor_file c d rc
    if [ "$rc" == "1" ]; then
        echo "Raw=${c}"
        echo "Celsius=${d}"
    else
        >&2 echo -n "."
    fi
    done
  sleep 0.2
done;