capture.sh

#!/bin/bash

SAVEDIR=/home/pi/timelapse/img
TIME_NIGHT_START=2035
TIME_NIGHT_STOP=700


# temp
TEMP=$(cat /home/pi/temperature)
HUM=$(cat /home/pi/humidity)


now=$(date +"%k%M")
filename=$(date -u +"%Y-%m-%d_%H%M-%S").jpg

# interval between 2 shots; should take in account the exposure time
SLEEP_TIME=30

# time of exposure for night capture
NIGHT_EXPOSURE_TIME=5

EXTRA_OPTIONS=${EXTRA_OPTIONS:=""}

FONT=/home/pi/timelapse/DroidSansFallback.ttf

if (( $now > $TIME_NIGHT_START)) || (($now < $TIME_NIGHT_STOP ))
then
EXTRA_OPTIONS="$EXTRA_OPTIONS -ISO 200 -ss $(( $NIGHT_EXPOSURE_TIME * 1000000 )) -ex night"
fi

function take_picture {
	filename=$(date -u +"%Y-%m-%d_%H%M-%S").jpg
	/opt/vc/bin/raspistill -a 12 $EXTRA_OPTIONS -o $SAVEDIR/$filename
	convert -font $FONT -pointsize 60 -fill white -stroke black -strokewidth 2 -draw 'text 296,60 "Temp: $TEMP Hum: $HUM%"' $SAVEDIR/$filename $SAVEDIR/$filename
}


take_picture

echo Sleeping for $SLEEP_TIME seconds
sleep $SLEEP_TIME

take_picture