Fetch data from USB-WDE1 receiver and write it to RRDTool database

fetch_wde_data.sh

#!/usr/bin/env bash
# Receive weather data from remote USB WDE1 and store it into database

# Loop forever to read data from USB WDE1
socat / dev/ttyUSB0, B9600 STDOUT | \
while read line
do
   if [["$ {line%% *}" == '$ 1']] then
       # Format data
       "{? line # 1, 1,} $" tmp = `echo | tr ',' ','`.
       data = `echo" $ {tmp% N% 0} "| sed 's / :: /: U :/ g' | sed 's / :: /: U :/ g'`
       data = $ data {%%}
       # Update rrd
       rrdtool update temperatures.rrd $ data
   fi
done

I think you have a mistake in line 15 :)