Home Security System Howto:

[jeff.sadowski]

I decided to make my own home brew security system and thought it would be nice to share my code.

I bought one of these
http://www.desktopaviator.com/Produc...2040/index.htm
It is designed to add buttons to flight simulators but it worked perfect for my alarm system. It was $33

I wrote a small program to use it as follows

alarm.c

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(int argc,char** argv)
{
 int fd,buttons;
 static char buttons_int[13];

 if(argc!=2)
 {
  fprintf(stderr,"Usage: alarm <script or program to run that reads the environment variable BUTTONS_INT>\n");
  exit(1);
 }

 if(fork())
 {/*Make a deamon*/
  exit(0);
 }

 while(1)
 {
  fd=open("/dev/alarm",O_RDONLY);
  read(fd,&buttons,sizeof(int));
  close(fd);
  snprintf(buttons_int,13,"%i",buttons);
  setenv("BUTTONS_INT",buttons_int,1);
  system(argv[1]);
  usleep(10000);
 }
 return 0;
}

compile it with
gcc -o alarm alarm.c

second_watch.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

int main(int argc,char** argv)
{
 if(argc!=2)
 {
  fprintf(stderr,"Usage: second_watch <script to run every second>\n");
  exit(1);
 }

 if(fork())
 {/*Make a deamon*/
  exit(0);
 }

 while(1)
 {
  system(argv[1]);
  sleep(1);
 }
 return 0;
}

to compile
gcc -o second_watch second_watch.c

sudo cp alarm /usr/sbin/alarm
sudp cp second_watch /usr/bin/

install mysql to make using it easy
sudo apt-get install mysql-server mysql-client

create a script to use with it

/root/alarm_script.sh

#!/bin/bash
. /etc/alarm/mysql_root_info.sh
. /etc/alarm/mysql_info.sh
. /etc/alarm/alarm_definitions.sh
. /etc/alarm/functions.sh
PADDING="000000000"

if [ "${BUTTONS_INT}" = "" ];then
BUTTONS_INT=`get_default`
fi
SINCEEPOCH=`date "+%s"`
NANOSECOND=`date "+%N"`

post(){
echo -e "insert into alarm (timestamp,nanosecond,state) values (${SINCEEPOCH},${NANOSECOND},${BUTTONS_INT});" | mysql "${database}" -u "${rootusername}" --password="${rootpassword}"
sleep 2;
activity=`echo "select timestamp,nanosecond,state from alarm order by timestamp desc,nanosecond desc limit 1;"|mysql ${database} -u "${username}" --password="${password}"|grep -v timestamp|awk '{print $1 "." $2 "-" $3}'`
TS=`echo ${activity}|cut -d. -f1`
NS=`echo ${activity}|cut -d. -f2|cut -d- -f1`
ST=`echo ${activity}|cut -d- -f2`
NS_SIZE=`echo -e ${NS}|wc -c`
let PADDING_NEEDED=10-${NS_SIZE}
if [ ${PADDING_NEEDED} -gt 0 ];then
NS=`echo ${PADDING} | cut -c ${PADDING_NEEDED}``echo -e "${NS}"`
activity=${TS}.${NS}-${ST}
fi

old_state=`echo "select timestamp,nanosecond,state from state order by timestamp desc,nanosecond desc limit 1;"|mysql ${database} -u "${username}" --password="${password}"|grep -v timestamp|awk '{print $3}'`

if [ "${SINCEEPOCH}.${NANOSECOND}-${BUTTONS_INT}" = "${activity}" ] && [ "${BUTTONS_INT}" != "${old_state}" ];then
 echo -e "insert into state (timestamp,nanosecond,state) values (${SINCEEPOCH},${NANOSECOND},${BUTTONS_INT});" | mysql "${database}" -u "${rootusername}" --password="${rootpassword}"
else
 if [ "${BUTTONS_INT}" != "${old_state}" ];then
  echo "${SINCEEPOCH}.${NANOSECOND}-${BUTTONS_INT}" != "${activity}" > /tmp/chatter.txt
 else
  echo state has not changed > /tmp/chatter.txt
 fi
fi
}
post &

create a script to start it via crontab

/root/checkalarm.sh

alarmpid=`ps h -C alarm`
if [ "$alarmpid" = "" ];then
/root/alarm /root/alarm_script.sh
fi

sudo crontab -e

* * * * * /root/checkalarm.sh

create scripts to use it from a regular user

second_watch_alarm.sh

#!/bin/bash
. /etc/alarm/alarm_definitions.sh
. /etc/alarm/functions.sh
. /etc/alarm/mysql_info.sh
lastseenfile=${HOME}/.alarm/lastseen.txt

cd ${HOME}/.trusted
recipients=`ls -1 *@* 2>/dev/null`
email_recipients=`echo -e "${recipients}"|grep -v "[0-9]\{9\}@.*"`
phone_recipients=`echo -e "${recipients}"|grep "[0-9]\{9\}@.*"`

lump_10()
{
 if [ ! -f ${lastseenfile} ];then
  mkdir -p ${HOME}/.alarm
  echo 0.0 > ${lastseenfile}
 fi

 lastseen=`cat ${lastseenfile}`
 TS="`echo -e "${lastseen}"|cut -d. -f1`"
 NS="`echo -e "${lastseen}"|cut -d. -f2`"

 activity=`echo "select timestamp,nanosecond,state from state where (timestamp > ${TS}) or (timestamp = ${TS} and nanosecond 
> $NS) order by timestamp desc,nanosecond desc;"|mysql ${database} -u "${username}" --password="${password}"|grep -v timestam
p|awk '{print $1 "." $2 "-" $3}'`

 if [ "`echo -e "${activity}"|wc -c`" = "1" ];then
  return
 fi
 sleep 10;

 if [ ! -f ${lastseenfile} ];then
  mkdir -p ${HOME}/.alarm
  echo 0.0 > ${lastseenfile}
 fi

 lastseen=`cat ${lastseenfile}`
 TS="`echo -e "${lastseen}"|cut -d. -f1`"
 NS="`echo -e "${lastseen}"|cut -d. -f2`"

 activity=`echo "select timestamp,nanosecond,state from state where (timestamp > ${TS}) or (timestamp = ${TS} and nanosecond > $NS) order by timestamp desc,nanosecond desc;"|mysql ${database} -u "${username}" --password="${password}"|grep -v timestamp|awk '{print $1 "." $2 "-" $3}'`

 lastseennow=`echo -e "$activity" | head -n 1|cut -d- -f1`
 if [ "${lastseennow}" != "" ];then
  echo ${lastseennow} > ${lastseenfile}
 fi

 for item in `echo -e "${activity}"`; do
  TS="`echo ${item}|cut -d. -f1`"
  ST="`echo ${item}|cut -d- -f2`"
  TSH=`date -d @${TS} "+%H:%M:%S"`
  echo "${TSH} `alarm_status ${ST}`"
 done
}

watcher()
{
 sleep 1;
 data="`lump_10`"
 if [ "$data" != "" ]; then
  for recipiant in ${email_recipients}; do
   if [ -f ${HOME}/.armed/${recipiant} ];then
    /bin/echo -e "$data" | sudo /usr/sbin/scripts/sendEmail \
          -t "${recipiant}" \
          -u "alarm status `date "+%F"`" \
          1> /dev/null 2>/dev/null
   fi
  done
  for recipiant in ${phone_recipients}; do
   if [ -f ${HOME}/.armed/${recipiant} ];then
    /bin/echo -e "$data" | sudo /usr/sbin/scripts/sendEmail \
          -t "${recipiant}" \
          1> /dev/null 2>/dev/null
   fi
  done
 fi
}

watcher

watcher.sh

#!/bin/bash
watch(){
running=`ps h -f -C second_watch|grep ^\`whoami\`\ `
if [ "${running}" = "" ]; then
 second_watch ${HOME}/second_watch_alarm.sh
fi
}

watch 2>/dev/null >/dev/null

make sure it gets started using crontab
crontab -e

* * * * * ${HOME}/watcher.sh

create the common files

/etc/alarm/alarm_definitions.sh

# the item names are the name you want it to send you
# the stat names are the default state of each
# for normally open switches(most alarm reed switches)
# the default state is 0
# for normally closed switches ( I found a couple of these for my windows that I wired in parallel) 
# the default state is 1 
# also disconnected items default states are 0
STATION_ITEM[1]="Front Door";
STATION_STAT[1]="0";
STATION_ITEM[2]="Bedroom Window";
STATION_STAT[2]="0";
STATION_ITEM[3]="Living Room Window";
STATION_STAT[3]="1";
STATION_ITEM[4]="Station 4";
STATION_STAT[4]="1";
STATION_ITEM[5]="Station 5";
STATION_STAT[5]="1";
STATION_ITEM[6]="Station 6";
STATION_STAT[6]="1";
STATION_ITEM[7]="Station 7";
STATION_STAT[7]="1";
STATION_ITEM[8]="Station 8";
STATION_STAT[8]="1";
STATION_ITEM[9]="Station 9";
STATION_STAT[9]="1";
STATION_ITEM[10]="Station 10";
STATION_STAT[10]="1";
STATION_ITEM[11]="Station 11";
STATION_STAT[11]="1";
STATION_ITEM[12]="Station 12";
STATION_STAT[12]="1";
STATION_ITEM[13]="Station 13";
STATION_STAT[13]="1";
STATION_ITEM[14]="Station 14";
STATION_STAT[14]="1";
STATION_ITEM[15]="Station 15";
STATION_STAT[15]="1";
STATION_ITEM[16]="Station 16";
STATION_STAT[16]="1";
STATION_ITEM[17]="Station 17";
STATION_STAT[17]="1";
STATION_ITEM[18]="Station 18";
STATION_STAT[18]="1";
STATION_ITEM[19]="Station 19";
STATION_STAT[19]="1";
STATION_ITEM[20]="Station 20";
STATION_STAT[20]="1";

chmod 0755 /etc/alarm/alarm_definitions.sh

/etc/alarm/mysql_info.sh

username=alarmviewer
password=alarmviewerpassword
database=alarm

chmod 0755 /etc/alarm/mysql_info.sh

/etc/alarm/mysql_root_info.sh

rootusername=root
rootpassword=password4mysql_root_user

chmod 0700 /etc/alarm/mysql_root_info.sh


/etc/alarm/functions.sh

get_default(){
 full=00000000000000000000000000000000
 bin=""
 for counter in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20; do
  if [ ${STATION_STAT[${counter}]} = 0 ];then
   bin="1${bin}"
  else
   bin="0${bin}"
  fi
 done
 let len=33-`echo $bin | wc -c`
 echo 10o2i${pad}${bin}p | dc
}

int2bin()
{
 full=00000000000000000000000000000000
 bin=`echo 2o10i${1}p | dc 2>/dev/null`
 let len=33-`echo $bin | wc -c`
 pad=`echo ${full}|cut -c 1-${len}`
 echo ${pad}${bin}
}

alarm_status()
{
OPENED=""
BUTTONS=`int2bin $1`
for counter in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20; do
 let otherend=33-counter;
 BUTTON=`echo $BUTTONS|cut -c $otherend`;
 if [ "$BUTTON" = "${STATION_STAT[$counter]}" ];then
  OPENED="${OPENED}${STATION_ITEM[$counter]},";
 fi
done

if [ "${OPENED}" = "" ];then
 echo "all closed"
else
 echo -e "${OPENED}" | sed s/",$"//
fi
}

chmod 0755 /etc/alarm/functions.sh

create the udev using this script

serial=`sudo lsusb -d 6017:3522 -v|grep iSerial|awk '{print $3}'`
echo KERNEL==\"hidraw\*\", ATTRS{manufacturer}==\"Desktop Aviator\", ATTRS{product}==\"Digital Switch 2040\" , ATTRS{serial}==\"$serial\" , SYMLINK+=\"alarm\" > 50-alarm.rules
sudo cp 50-alarm.rules /etc/udev/rules.d/
rm 50-alarm.rules
sudo service udev restart

create the database using this script

. /etc/alarm/mysql_info.sh
. /etc/alarm/mysql_root_info.sh
echo "create database ${database};" | mysql -u ${rootusername} --password="${rootpassword}"
echo "create table alarm (timestamp bigint,nanosecond int,state int);" |mysql ${database} -u ${rootusername} --password="${rootpassword}"
echo "create table state (timestamp bigint,nanosecond int,state int);" |mysql ${database} -u ${rootusername} --password="${rootpassword}"
echo "create user '${username}'@'localhost' IDENTIFIED BY '${password}';"|mysql -u ${rootusername} --password="${rootpassword}"
echo "grant select on ${database}.* to '${username}'@'localhost' identified by '${password}';"|mysql -u ${rootusername} --password="${rootpassword}"

create sendEmail script
/usr/sbin/scripts/sendEmail

#!/bin/bash
username="gmail_account_for_computer"
password="gmail_password"

sendEmail -f "${username}@gmail.com" \
          -s smtp.gmail.com:587 \
          -o tls=yes \
          -xu "${username}" \
          -xp "${password}" \
          $*

chmod 0700 /usr/sbin/scripts

add users that can send email to sudoers

echo ALL ALL=NOPASSWD:/usr/sbin/scripts/sendEmail >> /etc/sudoers

================================================== ==============

I saw an arduino for $25 here http://shop.amcnano.com/Arduino-Duemilanove-SKU2001.htm
there are not as many inputs but plenty for most home security systems. When I get a hold of one I will try replacing my alarm system. There shouldn't be many modifications needed to implement the arduino

[rookcifer]

LOL, dude, that is some GEEK stuff right there. I think we should give you some sort of award for geek project of the year or something.

[jeff.sadowski]

LOL, dude, that is some GEEK stuff right there. I think we should give you some sort of award for geek project of the year or something.

You have to wait I'm getting a relay control board that I will use to control my garage door and maybe a sprinkler system.

I also have a usb thermometer that I may use with my relay controller to act as a thermostat.

I also setup my computer to read email from my addresses and can send it commands. I will post that code latter.

[CharlesA]

That sounds like an interesting project.

[sladekal]

This looks exactly like what i have been looking for. Just a few questions. What about power requirrments for a switch say 25 feet away, or some kind of 10 to 1 or 20 to 1 wireless sensors?

[BkkBonanza]

What I don't understand is: if you have written a C program to do part of this then why not just make the C program do the whole thing? It appears you monitor switches and log them to mysql, and it seems you have a crontab to start scripts that then monitor another script, or something.

Why not just have a C program that starts and runs as daemon that monitors the switches and logs to mysql. You can connect and write to mysql from within C very easily using the mysql client library. That would be simpler.

You start the daemon during boot by adding an init conf file and it will be monitored by init anyway (so that if it gets killed it will be restarted automatically). No need for watcher scripts and crontabs.

Anyway, just saying. As it looks interesting but a rather complicated approach.

(note, is your sendEmail script recursive? it appears to call itself and seems like an error. shouldn't it be calling sendmail?)

[jeff.sadowski]

What I don't understand is: if you have written a C program to do part of this then why not just make the C program do the whole thing? It appears you monitor switches and log them to mysql,

I believe in the old unix way to use programs that already exist for the majority of the work. I could have had the c program work with mysql and all but I think it would have been more complicated and database specific.
I like the database approach but with my simple program its easy to modify it to do it any number of ways.

and it seems you have a crontab to start scripts that then monitor another script, or something.

Because I wasn't sure how reliable it was I wanted it to restart itself if it stopped running also it helps restart it if I unplug it and replug it back in.

Why not just have a C program that starts and runs as daemon that monitors the switches and logs to mysql. You can connect and write to mysql from within C very easily using the mysql client library. That would be simpler.

answered above.

You start the daemon during boot by adding an init conf file and it will be monitored by init anyway (so that if it gets killed it will be restarted automatically). No need for watcher scripts and crontabs.

I may look into moving it out of cron as it creates a lot of log entries in syslog however startup script may not be the best option as I may unplug it or it may get killed (looking less likely as it has been pretty reliable)

Anyway, just saying. As it looks interesting but a rather complicated approach.

Maybe I could make it a little easier but I love how I can run applications from email and I use that scripting to arm the alarm.
Its a hodge podge of exiting scripts that I use for all sorts of things.

(note, is your sendEmail script recursive? it appears to call itself and seems like an error. shouldn't it be calling sendmail?)

Yes it is recursive. I was running into trouble with it only reading one email per minute as I sent it email and now it works good. It should stop when there is no email left. I'll walk through it and make sure its doing what I say but it hasn't slowed down the box yet and its been running for about 4 months now.

You don't really need a database method but before I did that I was running into all sorts of race conditions and I didn't feel like writing a lot of locks and unlocks. I didn't want to deal with it. It sort of creates a database in my email as I set my email address as always armed.

-------------------------------------

I also added a motion sensor and I'll see if I can explain how to hook it up. But I wouldn't recommend it for someone that isn't familiar with diodes. Pretty much you want to keep the high(+5V) from reaching the return pin of the switch and allow the ground to flow. I'm using a radio shack one that I picked up for about $10.

Also I have about 30 events per day notes for anyone interested in implementing this. Its too many for my phone(I don't have a cellphone plan that has unlimited text messages) so I only arm it from time to time. I try to remember to arm it when I leave and disarm it about when my wife gets home. I also may wish to add noise creators but not sure what I want to do with this it may be more helpful if its quite as the cops may be able to catch them. I also have my house wired with a cat5 out to a port facing the front and back porches that I want to figure out a good way to put a camera in those two locations. I tried usb to cat5 converters (which I use with my alarm and you can get for $15) but the usb cameras I tried using didn't work well over them. I'll try some cheaper usb1 cameras that should work better with the cheaper usb over cat5 converters there is also the option of getting $300 convertors to support hi-def usb cameras that I want to use.

[jeff.sadowski]

This looks exactly like what i have been looking for. Just a few questions. What about power requirrments for a switch say 25 feet away, or some kind of 10 to 1 or 20 to 1 wireless sensors?

This may be why I have a few glitches from time to time but they could also be from the wind hitting the window enough to cause it to wiggle the switch. In any effect. It seems to work ok for me. For its price I though it was worth testing. It works pretty good for me. I have some of my switches more than 20 feet away. Alarm systems don't use something all that different. Its a detect for continuity. The computers they use are dumb in comparison I learned that they too have a jitter detect and wait a bit of time on a switch action. Oh and that is why I use two tables in my database. If someone has a better way I'd like to see it.

[BkkBonanza]

The problem with switch contacts is handled using what is called "debouncing" in embedded systems projects or electronics. You can usually handle it with by testing twice 10-15 millseconds apart and making sure the value is consistent. So a small delay and re-confirm the read should work.

I'm not sure what tech the board's chips are based on but typically cmos/ttl levels signals degrade after about 10 ft or so due to wire resistance causing signal loss/corruption. Again the debouncing should help but also there are driver chips that are better suited than others for long line signals. Sometimes a transistor on the input can be used to clean it up but that's a hassle when it's not built in.

There are wifi cameras around that could send video to your network. They're a fair bit more costly than the cheap usb webcams though. I helped a friend set up a video monitoring system for his restaurant using some linux webcam grabber software and usb webcams. But usb again isn't very good at long distances and my experience with the extenders and cat5 converters was very inconsistent. They work far better for single frame grabs at intervals than video streams.

Another approach I thought of before but didn't follow through on - that would give awesome quality - is using a cheap digicam and an Eye-Fi SD memory card that sends the images via wifi to the computer. Neither are real cheap but they're not that costly either.

[jeff.sadowski]

There are wifi cameras around that could send video to your network.

Wifi and security are nearly mutually exclusive. You can lock it down by some degree but no matter what its going over the air. Also wifi cameras come in to the price range of me just wanting to go another route anyways.