pcDuino will email you when water leakage happens

In this tutorial, we show how to make a water leakage detector that is powered by pcDuino. When water is detected, pcDuino will send out email to the target email.

To detect water, we use the moisture sensor from DFRobot. There are three pins of moisture sensor, GND, VCC, and S. S is connected to A2 of pcDuino, and GND of the sensor is connected to GND of pcDuino, while VCC of sensor is connected to 5V of pcDuino.

Now, lets look at code part.

1. Download Python library:

1	`$git clone https://github.com/pcduino/python-pcduino.git`

2. After that, we will see the library files under pcduino. Create a directory named ‘waterdetect’ under directory ‘Samples’, the following is the code:

#!/usr/bin/python 
#-*- coding: utf-8 -*-
import smtplib
 
import time
from adc import analog_read
 
server= 'smtp.gmail.com'
port = 587
 
sender = 'xxxxx@gmail.com'
recipient = 'yyyy@linksprite.com'
password='xxxx'
subject = 'Water Leakage Detected'
body = 'Water detected at basement water heater 1.'
 
def delay(ms):
    time.sleep(1.0*ms/1000)
 
def setup():
        print "read channel ADC2 value ,the V-REF = 3.3V"
        delay(3000)
 
body = "" + body + ""
 
headers = ["From: " + sender,
           "Subject: " + subject,
           "To: " + recipient,
           "MIME-Version: 1.0",
           "Content-Type: text/html"]
headers = "\r\n".join(headers)
 
def loop():
    while(1):
        value = analog_read(2)
    voltage = (value * 3.3)/4096
        print ("value =  %4d"%value)
    print ("voltage =  %4.3f  V" %voltage)
        if voltage > 3.0 :
             session = smtplib.SMTP(server, port)
             session.ehlo()
             session.starttls()
             session.ehlo
             session.login(sender, password)
             session.sendmail(sender, recipient, headers + "\r\n\r\n" + body)
             session.quit()
 
    delay(1000)
 
def main():
    setup()
    loop()
 
main()

We will set up to run python script as daemon at boot time.

To do this, you must create this file and save it in /etc/init.d/. The file name we choose is ‘waterdetect’:

#!/bin/sh -e 
 
DAEMON="/home/ubuntu/python-pcduino/Samples/waterdetect/waterdetect.py"
DAEMONUSER="ubuntu"
DEAMON_NAME="waterdetect.py"
 
PATH="/sbin:/bin:/usr/sbin:/usr/bin"
 
test -x $DAEMON || exit 0
 
. /lib/lsb/init-functions
 
d_start () {
        log_daemon_msg "Starting system $DEAMON_NAME Daemon"
        start-stop-daemon --background --name $DEAMON_NAME --start --user $DAEMONUSER --exec $DAEMON
        log_end_msg $?
}
 
d_stop () {
        log_daemon_msg "Stopping system $DEAMON_NAME Daemon"
        start-stop-daemon --name $DEAMON_NAME --stop --retry 5 --name $DEAMON_NAME
          log_end_msg $?
}
 
case "$1" in
 
        start|stop)
                d_${1}
                ;;
 
        restart|reload|force-reload)
                        d_stop
                        d_start
                ;;
 
        force-stop)
               d_stop
                killall -q $DEAMON_NAME || true
                sleep 2
                killall -q -9 $DEAMON_NAME || true
                ;;
 
        status)
                status_of_proc "$DEAMON_NAME" "$DAEMON" "system-wide $DEAMON_NAME" && exit 0 || exit $?
                ;;
        *)
                echo "Usage: /etc/init.d/$DEAMON_NAME {start|stop|force-stop|restart|reload|force-reload|status}"
                exit 1
                ;;
esac
exit 0

Do not forget to give execution rights to your python server and to the service script :

1 2	`$ sudo chmod 755 /etc/init.d/waterdetect` `$ sudo chmod 755 /home/ubuntu/python-pcduino/Samples/waterdetect/waterdetect.py`

You can start or stop it using:

$ sudo service waterdetect start

* Starting system waterdetect.py Daemon [ OK ]

$ sudo service waterdetect status

* /home/ubuntu/python-pcduino/Samples/waterdetect/waterdetect.py is running

$ sudo service waterdetect stop

* Stopping system waterdetect.py Daemon [ OK ]

and define it as a startup service using:

1	`$ sudo update-rc.d waterdetect defaults`

We install the detector at the washer machine:

When there are water spill, we got the email: