Monitoring the Trash Can

[Khanh]

Status of trash can in public area is monitored. When the trash can is full, an email is sent to trash manager or status of trash can on mysql database is updated.

Demonstration

How It Works

Distance sensor is used to measure distance from cover of trash can to surface of trash in trash can. When the distance is below a threshold, the trash can is considered as full, and we can send notification via email or update status on mysql database.


Things Used In This Project

• PHPoC Blue + USB Wi-Fi Dongle
• Ultrasonic Distance Sensor
• Jumper wires

Wiring Diagram





Source code

task0.php

<?php

if(_SERVER("REQUEST_METHOD"))
    exit; // avoid php execution via http request

include_once "/lib/sd_340.php";
include_once "/lib/sn_dns.php";
include_once "/lib/sn_esmtp.php";
include_once "/lib/sn_mysql.php";

define("FULL_THRESHOLD",  20); // in centimeter

// setup trigger pulse timer
ht_ioctl(1, "set mode output pulse");
ht_ioctl(1, "set div us");
ht_ioctl(1, "set repc 1");
ht_ioctl(1, "set count 5 10"); // 10us pulse width

// setup echo capture timer
ht_ioctl(0, "reset");
ht_ioctl(0, "set div us");
ht_ioctl(0, "set mode capture toggle");
ht_ioctl(0, "set trigger from pin rise");
ht_ioctl(0, "set repc 4");

$pre_dist = 0;
$count = 0;
$full_state = 0;

$dustbin_id = 3; // primary key in mysql if using mysql

function send_email()
{
    esmtp_account("[email protected]", "Dustbin");
    esmtp_auth("your_account", "your_password");
    esmtp_msa("smtp.gmail.com", 465);

    $time = date("Y:M-d-TH:i:s", time());

    $subject = "Dustbin is full";
    $message  = "Location: Planet Earth\r\n";
    $message .= "Time: $time\r\n";
    $message .= "Your dustbin is almost full\r\n";
    $message .= "Come there to get it!\r\n";

    $msg = esmtp_send("[email protected]", "Trash General Manager", $subject, $message);

    if($msg == "221")
        return true;
    else
        return false;
}

function update_mysql($dustbin_id, $state)
{
    //Enter your DB Server's hostname or IP address!
    $server_addr = "192.168.0.3";

    //Enter your account information!
    $user_name = "your_username";
    $password = "your_password";

    //Connect to DB Server
    if(mysql_connect($server_addr, $user_name, $password))
    {
        $result = mysql_select_db("employee");

        $result = mysql_query("INSERT INTO tbl_dustbin_state (dustbin_id, state, time) VALUES ($dustbin_id, '$state',  NOW());");

        if($result === true)
            return true;
        else
            return false;

        mysql_close();
    }
}

function dustbin_loop()
{
    global $full_state;
    global $pre_dist;
    global $count;

    ht_ioctl(0, "start"); // we should start capture timer first
    ht_ioctl(1, "start"); // start trigger pulse

    usleep(10000); // sleep 10ms

    // 1st capture value ("get count 0") is always zero.
    // we should get 2nd capture value;
    $us = ht_ioctl(0, "get count 1");

    if($us == 0)
        return $full_state;

    $dist = $us * 340.0 / 2; // us to meter conversion
    $dist = floor($dist / 10000); // meter to centimeter conversion

    echo "$dist\r\n";

    //filter noise
    if((float)$pre_dist != 0.0)
    {
        if(abs($dist - $pre_dist) <= 1)
            $count++;
        else
            $count = 0;
    }

    $pre_dist = $dist;

    if($count > 5)
    {
        if($dist < FULL_THRESHOLD)
            $full_state++;
        else
            $full_state = 0;
    }

    return $full_state;
}

$is_notified = false;
$pre_state = 0;

while(1)
{
    //if(ws_state(0) == TCP_CONNECTED)
    {
        $state = dustbin_loop();

        if($state != $pre_state)
        {
            switch($state)
            {
                case 0:
                    //update_mysql($dustbin_id, "EMPTY"); // uncomment this line if using mysql
                    $is_notified = false;
                    break;

                case 1:
                    sleep(4); // sleep and then do the sencond check to prevent the event that cover hides sensor
                    break;

                default:
                    // send notification
                    if($is_notified == false)
                    {
                        //if(update_mysql($dustbin_id, "FULL")) // uncomment this line if using mysql
                        if(send_email())
                        {
                            echo "notify/update successful\r\n";
                            $is_notified = true;
                        }
                        else
                            echo "notify/update mail failed\r\n";
                    }
            }

            $pre_state = $state;
        }
    }
}
?>

You can also see this project in hackster.io web site: https://www.hackster.io/phpoc_man/mo...ash-can-fe9368