hobolink APRS

#!/bin/bash

#Read data from HOBOlink station and send it to APRS network via Xastir. Server ports option has to be enabled on Xastir.

#Create a temporary RAM disk (we don't want to write on a SD card too often).
#You need to run this script as sudo (root) or create a temporary ramdisk at boot as root
#and run this script as a normal user.
if [ ! -d "/mnt/ramdisk/" ]; then
mkdir -p /mnt/ramdisk; mount -t tmpfs tmpfs /mnt/ramdisk -o size=10m
fi

#Check if file exist
if [ ! -f "/mnt/ramdisk/sequence_numberjavornik.txt" ]; then
touch /mnt/ramdisk/sequence_numberjavornik.txt
fi

#Read sequence number
read num < /mnt/ramdisk/sequence_numberjavornik.txt
num=$((num + 1))
if (( num == 1000 )); then
num=0
fi

#Error log file
error=/var/log/wxdata.log

#Define login info
user=S55MA-10
password=passcode

#Insert the same as user. Insert other user sign if you want to put another station not owned by you on the map. Be aware that telemetry
#requires 9 char long callsign so you need to add whitespaces after the callsign and telemetry, for example:
#t2="$usersend>APN002,WIDE2-1::"$usersend" :PARM.Solar Radiation,Battery" #5 whitespaces between "$usersend" and :PARM because
#S51Y is only 4 char long.
usersend=S51Y

#Define xastir server
server=192.168.0.140
port=2023

#Define station location (Veliki Javornik, Postojna)
lat=4545.48N
lon=01417.72E_ #_ is a symbol for WX station

#Download weather data
file=/mnt/ramdisk/wxdata.txt
file1=/mnt/ramdisk/wxdata1.txt
curl -s https://www.hobolink.com/p/d0a7b4f0dbc44b973b0a5cce75a0521d | grep nobr | awk -F\> '{print $6}' | sed 's/<\/nobr//g' > "$file"
curl -s https://www.hobolink.com/p/d0a7b4f0dbc44b973b0a5cce75a0521d | grep "Wind Direction" -A 1 | grep "latest-conditions-info-reading" | awk -F\> '{print $5}' | awk '{print $2}' | grep -o '[0-9]\+' > "$file1"

if [ -s "$file" ] #If downloaded file is not empty, continue, else quit
then

#Date in UTC
zuludate="$(date -u +%d%H%M)"

#APRS needs temperature in F, data is fetched in degress C so we need to convert it.
tempC="$(sed -n -e 1p "$file")"
tempF="$(echo "((9/5) * $tempC) + 32" | bc -l | awk -F. '{print $1}')"

#Relative humidity
rh="$(sed -n -e 2p "$file" | awk -F. '{print $1}')"

#APRS need windspeed in mph, data is fetched in meters per second so we need to convert it.
windspeedms="$(sed -n -e 4p "$file")"
windspeedmph="$(echo "(($windspeedms * 3.6) / 1.609344)" | bc -l | awk -F. '{print $1}')"
gustsms="$(sed -n -e 5p "$file")"
gustsmph="$(echo "(($gustsms * 3.6) / 1.609344)" | bc -l | awk -F. '{print $1}')"

rain1h="$(sed -n -e 7p "$file" | awk -F. '{print $1}')"
winddirection="$(cat "$file1")"
solarradiation="$(sed -n -e 6p "$file")" #For telemetry only
batteryvoltage="$(sed -n -e 8p "$file" | tr -d '.' | head -c 3)" #For telemetry only

#Station comment
aprscomment="Veliki Javornik 1268m asl"

#Xastir weather variable with padding zeros for correct APRS format
printf -v xastirwx "%03d/%03dg%03dt%03dr%03dh%02d%s" "$winddirection" "$windspeedmph" "$gustsmph" "$tempF" "$rain1h" "$rh" "$aprscomment"

#Xastir user and WIDE path data
xastirpath="$usersend>APN100,WIDE2-1:=$lat/$lon"

#Telemetry
printf -v t1 "%s>APN002,WIDE2-1:T#%03d,%03d,%03d,000,000,000,00000000" "$usersend" "$num" "$solarradiation" "$batteryvoltage"
t2="$usersend>APN002,WIDE2-1::$usersend :PARM.Solar Radiation,Battery"
t3="$usersend>APN002,WIDE2-1::$usersend :UNIT.W/m2,Volts"

#Add coefficient in EQNS field to convert real data.
t4="$usersend>APN002,WIDE2-1::$usersend :EQNS.0,1,0,0,0.01,0,0,0,0,0,0.0,0,0,0,0"
t5="$usersend>APN002,WIDE2-1::$usersend :BITS.00000000,Weather station Veliki Javornik Postojna"

#Send data to Xastir
/usr/bin/xastir_udp_client $server $port $user $password -to_rf "$xastirpath$xastirwx"

#Send telemetry data to Xastir
#Send PARAMS, UNITS, EQNS and BITS every 2 hours.
#Check if file exist
if [ ! -f "/mnt/ramdisk/datejavornik.txt" ]; then
echo 0 > /mnt/ramdisk/datejavornik.txt
fi

#calculate time difference
read olddate < /mnt/ramdisk/datejavornik.txt
date="$(date +%s)"
diff="$(echo "$date - $olddate" | bc)"

if [ "$diff" -gt 7200 ]; then
/usr/bin/xastir_udp_client $server $port $user $password -to_rf "$t1"
/usr/bin/xastir_udp_client $server $port $user $password -to_rf "$t2"
/usr/bin/xastir_udp_client $server $port $user $password -to_rf "$t3"
/usr/bin/xastir_udp_client $server $port $user $password -to_rf "$t4"
/usr/bin/xastir_udp_client $server $port $user $password -to_rf "$t5"
echo "$date" > /mnt/ramdisk/datejavornik.txt
else
/usr/bin/xastir_udp_client $server $port $user $password -to_rf "$t1"
fi

#Delete old data
rm -f /mnt/ramdisk/wxdata.txt /mnt/ramdisk/wxdata1.txt

#Write sequence number
echo "$num" > /mnt/ramdisk/sequence_numberjavornik.txt

else
echo ["$(date -u)"] Error downloading data >> "$error"
fi