Published September 11, 2020

The 30-40 Finder, Specific Area Monitoring Device using BOLT

Hey there meet the 30-40 finder, why 30-40? Well it monitors between a distance of 30 cm and 70 cm and so got a fancy name for it.

BeginnerFull instructions provided2 hours407

The 30-40 Finder, Specific Area Monitoring Device using BOLT

Things used in this project

Hardware components

Ultrasonic Sensor - HC-SR04 (Generic)

SG90 Micro-servo motor

Arduino UNO

Bolt IoT Bolt WiFi Module

Jumper wires (generic)

Software apps and online services

Arduino IDE

Twilio SMS Messaging API

Story

What if we were able to continuosly monitor a specific area and was able to know if some anonymous activity such as tresspassing (only examples) or any such activities took place, it would be great isn't? This project aims even though not completely but still in a way of doing that. If I were to give an example to justify my statement, lets take the case of India abt 10-20 elephants die every year due to train collisions, how miserable ! what if we were able to detect the prescence of elephants near the rail track and readily send an sms / phone call to the locomotive driver or forest officials so that they can come in time to save the lives of elephants. My project needs to be integrated with lot of other sensors such as IR sensor, PIR sensor, Seismo sensor, Alarms and much more to be able to completely achieve this, but this is a sort of miniature model., Well, there can be more uses like these with this project...So lets see the working principle

WORKING PRINCIPLE

The ultrasonic sensor continuosly monitors for any objects present between 30 cm and 70 cm and since i've attached a servo it could monitor more area and if an object is found then bolt fetches the serial data from arduino and sends the distance as an sms to your phone using Twilio. Thus a specific area is continuosly monitored

HARDWARE CONNECTIONS & SENSOR EXPLANATIONS

The ultrasonic sensor and servo motor are connected to arduino

Ultrasonic Sensor Pinout

There are 4 pins in the ultrasonic sensor out of which 2 are for the power i.e. vcc (+5v) and gnd(0v).The other two pins are trigger and echo connected to the digital pins of the Arduino with which we can measure the distance between an obstacle and the sensor. So I would briefly explain how it works, one of the sensor(the 2 big circles that you see on either side) continuously sends an ultrasonic signal and the other one will recieve the signal only if it has been rebounded from any obstacle and if it receives the signal then the time taken for the signal to travel from the sensor to obstacle and back to the sensor can be determined using echo pin and thus distance can be calculated. The trigger pin is used to send the ultrasonic signal.

Servo Motor pinout

Servo motor consists of 3 pins vcc(+5v), Gnd( 0v) and Control(PWM).The vcc and gnd pin can be connected to the vcc and gnd of arduino respectively where as the control pin should be connected to digital PWM pin of the Arduino (PWM pins can be found by looking for a tilde( ~ ) symbol near the pin number. This servo motor can sweep an area between 0 and 180 degrees

The tx and rx of arduino are connected to rx and tx of the bolt respectively which helps in serial communication between the 2 devices.

SETTING UP THE SENSOR WITH THE SERVO MOTOR

For connecting the servo to the sensor, An L shaped bracket of foam board was made and the ultrasonic sensor can be attached to this bracket using double sided tape and the bracket is attached to the servo motor and screwed in place.

SOFTWARE CONFIGURATION

If you dont have a twilio account then visit https://www.twilio.com/ and signup.

You will have to verify your e-mail and phone number inorder to use twilio.

After doing all these follow the below instructions:

1. Once you've logged in, You could see an arrow on the left top side. Click on it.

2. Now click on 'Create new project'.

3. Give it a name and some basic questions will be asked on what features we want to use etc.

4. Once you have setup everything you can see 'Get a trial number' and click on choose number and remember to save it, This will be the twilio number that we have to give in the python code

5. Also note down Auth Token and SID of your twilio account, these are also needed.

6. After all this is done, your sms part is ready!!!

Code

from boltiot import Bolt, Sms
import json, time

'''Using the boltiot library for configuring the bolt device , Sms is used to send custom message to any phone number
json is library present by default in python it is used to turn json type data into a python dictionary
time is used for delaying the code so that you wont receive infinite messages.'''

SID = 'You can find SID in your Twilio Dashboard'
AUTH_TOKEN = 'You can find  on your Twilio Dashboard'
FROM_NUMBER = 'This is the no. generated by Twilio. You can find this on your Twilio Dashboard'
TO_NUMBER = 'This is your number. Make sure you are adding +91 in beginning'
API_KEY = 'This is your Bolt Cloud accout API key'
DEVICE_ID = 'This is the ID of your Bolt device'

mybolt = Bolt(API_KEY, DEVICE_ID)#Create a bolt object
sms = Sms(SID, AUTH_TOKEN, TO_NUMBER, FROM_NUMBER)

while True:
   response = mybolt.serialRead('10')# Fetching the serial data from Arduino
   data = json.loads(response) #Using json to load the response as a python dictionary
   dist = data['value'].rstrip() #rstrip is used to remove any special characters in the data
   print(f"Object found at {dist} cm")
   respond = sms.send_sms(f"An object has been found at {dist} cm")#SMS is send if object is detected
   time.sleep(50) #The while loop executes only once every 50 seconds

#include <Servo.h> //The servo header files can be used to operated servo motors with ease

// The trigger and echo of the ultrasonic sensor are connected to digital pins 5 and 6 of Arduino
const int trigPin = 5; 
const int echoPin = 6;
//Duration and distance are for measuring distance between sensor and obstacle
long duration;
int distance;
Servo myServo; // Creates an object myservo of type Servo
 
void setup() 
{
  pinMode(trigPin, OUTPUT); 
  pinMode(echoPin, INPUT); 
  Serial.begin(9600);
  myServo.attach(11);
  // The control pin of servo is attached to digital pin 11 of Arduino
 // Make sure that the control is connected to a digital PWM pin and not a normal digital pin 
}
void loop() //The main loop
{
  for(int i=15;i<=165;i++)
  {  
    myServo.write(i);//write function writes the value into servo so it will spin that much degrees
    //from its initial position
    delay(30);
    distance = calculateDistance();//A calculateDistance function that returns the distance between
    //Obstacle and sensor
    if (distance > 30 && distance < 70)//The distance is printed in serial port only if the 
    //obstacle is between 30 and 70 cm  from the sensor
      {
      Serial.println  (distance); 
      }
  }
  for(int i=165;i>15;i--)//Same as above but the servo is going in reverse
  {  
    myServo.write(i);
    delay(30);
    distance = calculateDistance();
    if (distance > 30 && distance < 70)
      {
      Serial.println  (distance); 
      }
  }
}

int calculateDistance()//A function that returns the distance between sensor and obstacle as an
//integer
{ 
  digitalWrite(trigPin, LOW); 
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH); //An ultrasonic signal is send
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW); // The signal is recieved 
  duration = pulseIn(echoPin, HIGH); // Calculates the duration it takes for the signal to travel 
  distance= duration*0.034/2; // The duration is turned into distance 
  return distance;
}

The 30-40 Finder, Specific Area Monitoring Device using BOLT

Things used in this project

Hardware components

Software apps and online services

Story

WORKING PRINCIPLE

HARDWARE CONNECTIONS & SENSOR EXPLANATIONS

SETTING UP THE SENSOR WITH THE SERVO MOTOR

SOFTWARE CONFIGURATION

Schematics

Schematic File

Schematic Pic

BreadBoard Schematic

Code

Python Code

Arduino Code

Credits

NP Vishwajith

Comments

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The 30-40 Finder, Specific Area Monitoring Device using BOLT

The 30-40 Finder, Specific Area Monitoring Device using BOLT

Things used in this project

Hardware components

Software apps and online services

Story

WORKING PRINCIPLE

HARDWARE CONNECTIONS & SENSOR EXPLANATIONS

SETTING UP THE SENSOR WITH THE SERVO MOTOR

SOFTWARE CONFIGURATION

Schematics

Schematic File

Schematic Pic

BreadBoard Schematic

Code

Python Code

Arduino Code

Credits

NP Vishwajith

Comments

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