webcam

#!/usr/bin/env bash
###########################################################################
# Made by    : Ewoud Dronkert
# Licence    : GNU GPL v3
# Platform   : Raspbian
# Requires   : bash, ssh, scp
#              SSH key with access to storage (and/or web) server
#              Raspberry Pi camera
#              `raspistill' provided by Raspbian distribution
#              `sun' script to calculate local sunrise & sunset times
#              `timedelta' script to calculate twilight time difference
# Location   : /usr/local/bin/
# Invoke as  : As a make-shift service in /etc/rc.local: webcam &
# Name       : webcam
# Version    : 1.0.0
# Date       : 2018-01-31
# Purpose    : Take picture with Raspberry Pi camera, upload to server
# Settings   : TWILIGHT = number of minutes before sunrise and after sunset
#                when there is enough light for camera daylight settings
#              MEM = where to store local copy of new webcam image
#              SRV = user and server name for remote webcam image
#              DIR = remote server directory for webcam image
#              ID = location of SSH key with server access
###########################################################################

TWILIGHT=35                 # useful twilight duration in minutes
MEM='/run/shm/cam.jpg'      # store image not on card but in memory
SRV='username@servername'   # user and server with ssh (scp) access
DIR='serverdir/'            # remote server directory for images
ID='/home/pi/.ssh/id_rsa'   # SSH key with access to server

# Invalid time to force sunrise/set calc on script startup
PREV=2500

# Continuous loop
while true; do

	# Current time as 24h HMM without zeros in front
	CLOCK=$(date +'%-H%M' | sed -r 's/^0*([0-9])/\1/')
	if (( CLOCK < PREV )); then

		# Calculate new sunrise and sunset times for every new day
		set $(sun)
		DAWN=$(timedelta $1 -$TWILIGHT)
		DUSK=$(timedelta $2 +$TWILIGHT)

		# Update local external IP address if it is not fixed
		# in order to know where to connect to for maintenance
		#ssh -q -x -p 22 \
		#	-o "CheckHostIP no" \
		#	-o "BatchMode yes" \
		#	-o "ServerAliveInterval 10" \
		#	-o "ServerAliveCountMax 1" \
		#	-i "$ID" "$SRV" \
		#	"echo \${SSH_CLIENT%% *} > ${DIR}ip.txt && chmod 644 ${DIR}ip.txt"

	fi
	# Save current time for the next loop
	PREV=$CLOCK

	# Take picture
	if (( CLOCK >= DAWN && CLOCK <= DUSK )); then
		# Daylight settings
		raspistill \
			-n -w 1024 -h 768 -q 80 -st \
			-t 2000 \
			-ae 16,0x00,0x8080ff -a 1028 -a '%F %T' \
			-o "$MEM"
	else
		# Night time settings
		raspistill \
			-n -w 1024 -h 768 -q 80 -st \
			-t 1 -ss 2000000 -drc high \
			-ae 16,0xff,0x808000 -a 1028 -a '%F %T' \
			-o "$MEM"
	fi

	# Upload locally saved image to server
	scp -q -B -p -P 22 \
		-o "CheckHostIP no" \
		-i "$ID" \
		"$MEM" "$SRV:$DIR"

done