sstv-threaded.sh

#!/bin/bash

#
# SSTV Daemon
#
# This script will grab an image from a webcam,
# compile it as an SSTV image (Martin 1 or
# Robot 36) and then transmit it using the
# Dorji module.
#

# (C) Andrew Koenig 2014

GPIO=22		# GPIO Pin
PAN=2:0:1	# Left/Right Audio R -> 2:0:1 L -> 2:1:0
TXDELAY=.5	# Time (in seconds)
CYCLE=0		# Cycle time (seconds)
PROTOCOL=r36	# Martin 1 (m1), Robot 36 (r36), Scottie DX (sdx)
WAV=/mnt/ramdisk/image.png.wav
IMG=/mnt/ramdisk/image.png
COUNT=1

while ! [ -f /mnt/ramdisk/kill_sstv ] ; do
	# Establish start time
	TIME=`date +%s`

	# Establish the serial port
	SERIAL=`cat /home/pi/balloon/.radio`

	/home/pi/balloon/freq.py 144.5000 144.5000 0015 $SERIAL > /dev/null 2>&1

	# Send Martin 1 every 5 images
#	if [ $(($COUNT % 5)) -eq 0 ] ; then
#		PROTOCOL=sdx
#	else
#		PROTOCOL=r36
#	fi


	# Take picture
	echo -n "Taking picture.. "
	fswebcam --top-banner --title "K5UTD High Alt. Balloon" --subtitle 'Now in technicolor!' -S 120 $IMG > /dev/null 2>&1
	echo "done!"

	# Compile image into SSTV
	echo -n "Compiling SSTV wav file... "
	sstv -r 22050 -p $PROTOCOL $IMG > /dev/null 2>&1
	echo "done!"

	# Compile APRS packets while transmitting SSTV
	/home/pi/balloon/aprs-threaded-compile.sh &

	# Transmit
	echo -n "Transmitting... "
	echo 0 > /sys/class/gpio/gpio$GPIO/value
	sleep $TXDELAY
	mplayer $WAV -af pan=$PAN > /dev/null 2>&1
	echo 1 > /sys/class/gpio/gpio$GPIO/value
	echo "done!"

	# Run the APRS script
	/home/pi/balloon/freq.py 144.3900 144.3900 0015 $SERIAL > /dev/null 2>&1
	/home/pi/balloon/aprs-threaded-transmit.sh

	# Counter
	COUNT=$(($COUNT + 1))

	# Sleep
	TIME=$(($(date +%s) - $TIME))
	echo Executing took $TIME seconds, iteration number $COUNT
	if [ $(($CYCLE - $TIME)) -gt 0 ] ; then
		echo Sleeping $(($CYCLE - $TIME)) seconds...
		sleep $(($CYCLE - $TIME))
	else
		echo Not sleeping...
	fi
done