GPIOServer.sh

#!/bin/bash
{
# Initial Script created by Daniel Curzon (http://www.instructables.com/member/drcurzon).
# Initial version created 10th June 2012.
# Initial Version: 1.0.

# Heavily modified script by linwiz.
# January 7th 2015

# Set working directory.
dir="$(dirname "$0")"

# Read config file (relative).
source "$dir/GPIOServer.conf.sh"

# Retrieve revision information.
rev_cmd="python $dir/revision.py"
revision=`$rev_cmd`

addLogItem() {
    logdatas="$1 $2 $3"
    echo "INSERT INTO log (data) VALUES (\"$logdatas\");" | mysql --host=$mysqlhostname --user=$mysqlusername --password=$mysqlpassword $mysqldatabase;
}

addLogItem "Starting GPIO Server"
trap "addLogItem Stopping GPIO Server" EXIT

mysqlquery="mysql -B --host=$mysqlhostname --disable-column-names --user=$mysqlusername --password=$mysqlpassword $mysqldatabase"

# Retreive all pins.
pins=`echo "SELECT pinNumberBCM FROM pinRevision$revision" | $mysqlquery`

# Start Loop.
while true; do
	for PIN in $pins ;
		do
			# Enable or Disable pins accordingly.
			enabled[$PIN]=`echo "SELECT pinEnabled FROM pinRevision$revision WHERE pinNumberBCM='$PIN'" | $mysqlquery`
			if [ "${enabled[$PIN]}" == "1" ]; then
				if [ ! -d "/sys/class/gpio/gpio$PIN" ]
				then
					gpio export $PIN out
					if [ "$logging" ]; then addLogItem "Enabled Pin $PIN"; fi
				fi
			else
				if [ -d "/sys/class/gpio/gpio$PIN" ]
				then
					gpio unexport $PIN
					if [ "$logging" ]; then addLogItem "Disabled Pin $PIN"; fi
				fi
			fi

			# Skip disabled pins.
			if [ -d "/sys/class/gpio/gpio$PIN" ]; then

				# Read Pin Directions.
				direction[$PIN]=`echo "SELECT pinDirection FROM pinRevision$revision WHERE pinNumberBCM='$PIN'" | $mysqlquery`
				direction2=`cat /sys/class/gpio/gpio$PIN/direction`

				# Read Pin Status'.
				status[$PIN]=`echo "SELECT pinStatus FROM pinRevision$revision WHERE pinNumberBCM='$PIN'" | $mysqlquery`
				status2=`gpio -g read $PIN`

				# Change Pin Status'.
				if [ "${direction[$PIN]}" != "$direction2" ]; then
					if [ -n $PIN ]; then
						if [ -n ${direction[$PIN]} ]; then
							gpio -g write $PIN ${direction[$PIN]}
							if [ "$logging" ]; then
								addLogItem "Pin $PIN direction to: ${direction[$PIN]}"
							fi
						elif [ -z ${direction[$PIN]} ]; then
							addLogItem "PIN direction zero"
						fi
					elif [ -z $PIN ]; then
						addLogItem "PIN value zero"
					fi
				fi

				if [ "${status[$PIN]}" != "$status2" ]; then
					if [ -n $PIN ]; then
						if [ -n ${status[$PIN]} ]; then
							gpio -g write $PIN ${status[$PIN]}
							if [ "$logging" ]; then
								 addLogItem "Pin $PIN changed to: ${status[$PIN]}"
							fi
						elif [ -z ${status[$PIN]} ]; then
							addLogItem "PIN status zero"
						fi
					elif [ -z $PIN ]; then
						addLogItem "PIN value zero"
					fi
				fi
			fi
			sleep 0.2
	done

	# Complete Loop.
	sleep $waitTime
done
} >> /var/log/GPIOServer.log