#!/bin/bash'

# EbNaut SINGLE DECODE by IZ7SLZ july 2017 
# last rev. 08-2018


 
#### main

clear



#parameters
			DATA="2018-12-10" # ENTER DATE OF TRANSMISSION
			ORA="00:00:00"     #ENTER TIME OF TRANSMISSION
                FREQUENCY=137479.000 #ENTER QRG
                DIAL=136000          #ENTER VFO
                LIST=10000           #ENTER LIST LENGHT
                CHAR=5               #MESSAGE LENGHT
                SYM=3                #SYMBOL DURATION
                CRC=16               #CRC
                RATE=8               
			CONSTR=19
			T_OFFSET=0.0         
                F_OFFSET=0.000
                #PHASE="PS"  #select or deselect accordling
                PHASE="PU"
                #PHASE="PS15"
			#MSG="-f15 -f16 -M '*****'" #diagnostic
                
#CALCULATIONS
                TIMESTAMP=$DATA'_'$ORA
                T1=$(date -u --date="$DATA $ORA" +"%s")
			TIMEINIT=$(echo $T1-60 | bc -l)  #initial time 60s early  (in epoch)  
                

                CODE=$RATE'K'$CONSTR'A'
			FREQ=$(echo $FREQUENCY-$DIAL |  bc -l)   
                BITS=$(echo $CHAR*6+$CRC+$CONSTR-1 | bc  -l) 
                BITS=$(echo $BITS*$RATE | bc  -l)    # no. of symbols 

                DURAT=$(echo $BITS*$SYM | bc  -l)    # duration of the transmission   
                REC=$(echo $DURAT+ 61 | bc  -l)      # duration of the raw audio file
                DELAY=$(echo $T_OFFSET+ 60 | bc  -l) 
               



echo  $TIMESTAMP  $FREQUENCY'Hz N='$CHAR 'T='$SYM's' $CODE 'CRC='$CRC 'list='$LIST 'sym='$BITS 'Duration='$DURAT's'  >  DECODED1.TXT
echo  'T_OFFSET='$T_OFFSET's'  'F_OFFSET='$F_OFFSET'Hz'   >>  DECODED1.TXT

echo 'processing +'$REC 'seconds....'

echo '-----------------------------------------------------------------------------'

vtread  -v -T $TIMEINIT,'+'$REC /media/iz7slz/Storage/LF |     	# read LF raw
vtcat -p |
vtfilter -v -h bp,f=1500,w=3000 |          			# Pre-filter before blanking
vtblank -v -a21 -d0 -t300 |   	# sferic blanker settings 
vtmult -v -f $FREQ |                       	 		# Mix to baseband I/Q
vtresample -v -r 240 | 	              			# Reduce to 240 sample pairs/sec and save on file


vtraw -oa  |                  # Convert to 3-columns of ASCII

ebnaut -vv -dp$CODE -F$F_OFFSET -N$CHAR -S$SYM -r240 -k$CRC -c2 -L$LIST -T$DELAY -$PHASE $MSG  | tee -a DECODED1.TXT # Decode COMMAND


#./uploadebnaut  #invoke shell file with curl for upload files to website

echo
echo