Fermentation Temperature Control with Inkbird 308

#!/bin/bash
 
while true; do
 
    # Take photo using current date 
    DATE=$(date +"%Y-%m-%d-%H%M")
    raspistill -vf -hf -o $DATE.jpg
 
    ARRAY=()
    X=0
 
    # Try different thresholds
    for I in 90 80 70 60 50 40 30 20 10; do
 
        # Ensure there is at least PIX pixels
        for PIX in 50 20 5; do
             
            # Shear image by different amounts 
            for SHEAR in 65 10; do
 
                Z=$(../../ssocr/ssocr -d3 -i$PIX rotate 359 crop 600 825 1230 550 shear $SHEAR -t$I -f white ${DATE}.jpg -o dump.jpg)
     
                # Ensure exit code was 0, meaning OCR detected numbers of 3 digits
                if [ $? -eq 0 ] && [ "${Z: -1}" != "-" ]; then
                    echo $Z
                    # Store number from OCR as integer, convert b to 6 
                    # (as ssocr sometimes thinks 6 is B in hex)
                    NUMI=$(echo "$(echo $Z | sed "s/b/6/g")" | bc)  
                    ((ARRAY[$NUMI]++))
                    X=1
                fi
            done
        done
    done
 
    if [ $X -eq 0 ]; then
        # Failed to detect display correctly    
        echo ${DATE} >> bad
    else
        LOW=0
        LVAL=-1
 
        # Find best value out of possible candidate OCRd values
        for var in "${!ARRAY[@]}";
        do 
            # Check if this number appears the most common  
            if [ ${ARRAY[$var]} -gt $LOW ]; then
                LOW=${ARRAY[$var]}
                LVAL=$var
            fi
        done
         
        # Convert number to decimal
        NUM=$(echo "scale = 2; $LVAL / 10" | bc)
 
        # Write number to CSV
        echo "${DATE},$NUM" >> temps
         
        rm ${DATE}.jpg
    fi
 
    sleep 60
done

set key off
set term png transparent truecolor
set title "Fermentation Temperature" textcolor rgb "orange" font "Helvetica,50" 
set object 1 rectangle from graph 0, graph 0 to graph 1, graph 1 behind fc rgbcolor 'white' fs noborder
set term png size 2000,900 font "Helvetica,30" 
set xtics textcolor rgb "orange" 
set ytics textcolor rgb "orange" 
set output 'inkbird.png'
set datafile separator ','
set yrange [10:30]
set xdata time
set timefmt '%Y-%m-%d-%H%M'
set format x "%d %b %Y"
set xtics format "%d %b %Y %H\:%M"
set xtics rotate 90
set xtics 86400
plot 'temps.csv' using 1:2 with lines 

# Target temp value set on Inkbird
# Used to strip out values less than target-7 or greater target+7
# which are likely due to incorrect OCRing
 
TARGET="20.0"
 
LTARGET=$(echo "$TARGET - 7" | bc)
HTARGET=$(echo "$TARGET + 7" | bc)
 
cat temps | awk -F, '{ if ($2 >= $LTARGET && $2 <= $HTARGET ) print $1 "," $2 }' > temps.csv
 
gnuplot temp.plt