Keypad-controlled and industrial gas-monitoring wireless robot

INTRODUCTION:

This project demonstrates the use of xbee as the transceiver where the robot is controlled by keypad and amount of gas is measured wirelessly through the xbee. The robot can be moved to the place within the range OF 30m (indoor) or 100m (outdoor) to monitor the amount of gas present in air. The people only just need to operate the robot using the keypad in the receiver side, where humans no need to involve in entering to the place to measure some poisonous gas.

Keypad controlled and Industrial Gas Monitoring Wireless Robot

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COMPONENTS REQUIRED:

COMPONENTS	QUANTITY
Arduino Uno	2
Xbee S1 Module	2
4×3 Keypad	1
MQ135 Sensor	1
MQ7 sensor	1
Geared DC motor	1
L293D Motor driver IC	1
Battery 12V	1
Voltage Regulator 7805 and 7812 IC	7805 – 1 7812 – 1
Bread Board	2
Connecting Wires	As required
Indicator LED	1

BLOCK DIAGRAM:

TRANSCEIVER (CONTROLLING SIDE)

Keypad controlled and Industrial Gas Monitoring Wireless Robot Block Diagram

TRANSCEIVER (ROBOT SIDE):

Keypad controlled and Industrial Gas Monitoring Wireless Robot Block Diagram

Keypad controlled and Industrial Gas Monitoring Wireless Robot Block Diagram

PROJECT DESCRIPTION:

Keypad controlled and industrial gas monitoring wireless robot consist of 2 arduino microcontroller in which one setup is interfaced with the Keypad for controlling the direction of the robot and LCD to display the direction and amount of gas measured by robot and interfaced with xbee for wireless transmission and reception. Another setup is mounted on the robot which consists of arduino controller interfaced with xbee for receiving the data, for the movement of the robot with two DC motors with the wheels attached to it are fixed with chassis. As the motor cannot be directly controlled by the microcontroller, the H-bridge L293D motor driver IC is used to control the motor, MQ135 and MQ7 sensor is used to measure the gas present in the air. The required power to microcontroller, sensors and motor driver are provided with the help of 12v battery connected to 12v and 5v voltage regulator. The complete circuit diagram, connections and working are explained below.

CIRCUIT CONNECTIONS:

One Arduino MEGA and One Arduino UNO are used in this project, where one is used in transmitter side and another in the receiver side.

TRANSCEIVER (CONTROLLING SIDE):

Keypad controlled and Industrial Gas Monitoring Wireless Robot

ARDUINO UNO:

The Arduino MEGA 2560 is designed for projects that require more I/O lines, more sketch memory and more RAM. With 54 digital I/O pins, 16 analog inputs and a larger space for your sketch it is the recommended board for 3D printers and robotics projects. This gives your projects plenty of room and opportunities maintaining the simplicity and effectiveness of the Arduino platform. While programming the board can be connected to the PC using USB port and the board can runs on USB power, to know more Arduino Uno.

POWER SUPPLY:

In the circuit, Arduino board, LCD and xbee module need a 5V regulated DC supply for operation. The supply to the arduino board is powered with 5v by USB cable. The voltage input for xbee, LCD is drawn from 5V Vout pin of arduino.

KEYPAD:

In this project, we will be using Keypad to control the movement of robot by pressing the specific number on number. This keypad contains 12 buttons with three columns and 4 rows. In the keypad 4-wire is used as ROWS and three wires are used as COLUMS. Wire number can be count from the left hand side to the right hand side.

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KEYPAD PIN	ARDUINO MEGA PIN.NO
R1	41
R2	43
R3	45
R4	57
C1	49
C2	51
C3	53

XBEE S1 MODULE:

Zigbee is a wireless communication module which use IEEE 802.15.4 standard. 802.15.4 is a IEEE standard for low power applications of radio frequency. It used in many products for wireless communication functionality. It can be used as a transmitter and receiver both. It uses serial communication to send and receive data. It has two series, series 1 and series 2. Series 1 is comparatively easy to use and it is recommended for beginners. Here in this project we use series 1 xbee. Series 1 zigbee module cannot work in mesh network. Mean it cannot talk to more than one zigbees. Here It forms simple serial communication where TX of xbee is connected with RX of arduino and RX of xbee to TX of arduino. In this part Xbee acts as a transmitter part. To learn more click here Zigbee.

LCD MODULE:

The 16X2 LCD display will be used to display the distance measured and direction of robot. It is connected to the Arduino board by connecting its data pins to pins 3 to 6 of the Arduino board. The RS and E pins of the LCD are connected to pins 13 and 12 of the Arduino MEGA respectively. The RW pin of the LCD is grounded.

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LCD	ARDUINO UNO
RS	13
RW	GRND
E	12
D7 , D6, D5, D4	3, 4, 5, 6 respectively

The standard open-source library for interfacing LCD with Arduino MEGA is used in the project. The library works as expected and needs no changes or modifications.

TRANSCEIVER (ROBOT SIDE):

Keypad controlled and Industrial Gas Monitoring Wireless Robot

ARDUINO UNO:

The Arduino uno is ATmega328 based microcontroller board. The board comes with built-in arduino bootloader. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, an on-board resonator, a reset button, and holes for mounting pin headers. While programming the board can be connected to the PC using USB port and the board can runs on USB power, to know more Arduino Uno.

POWER SUPPLY:

In the circuit, Arduino board, Motor Driver IC supply, MQ135 and MQ7 Sensor and the Xbee module need a 5V regulated DC while DC motor needs 12V regulated DC for its operation. The 12V NIMH battery is used as major power supply. The output from battery is regulated to 5V and 12V using 7805 and 7812 ICs. The pin 1 of both the voltage regulator ICs is connected to the anode of the battery and pin 2 of both ICs is connected to ground. The respective voltage outputs are drawn from pin 3 of the respective voltage regulator ICs. A LED along with a 1KΩ pull-up resistor is also connected between common ground and output pin to get a visual hint of supply continuity.

MQ135 SENSOR:

MQ-135 Module sensor has lower conductivity in clean air. When the target combustible gas exist, the sensors conductivity is higher along with the gas concentration rising. Convert change of conductivity to correspond output signal of gas concentration. MQ135 gas sensor has high sensitivity to Ammonia, Sulphide and Benzene steam, also sensitive to smoke and other harmful gases. It is with low cost and suitable for different applications such as harmful gases/smoke detection. The analog output is connected to the A1 pin of the arduino to measure the gas concentration in air.

MQ7 SENSOR:

The MQ-7 is a Carbon Monoxide (CO) sensor suitable for sensing CO concentrations in the air. It can detect CO-gas concentrations anywhere from 20 to 2000 ppm. It makes detection by method of cycle high and low temperature, and detects CO at low temperature. It is widely used in domestic CO gas leakage alarm, industrial CO gas alarm and portable CO gas detector. The analog pin of sensor is connected to the A0 pin of arduino UNO.

L293D MOTOR DRIVER:

L293D is a dual H-bridge motor driver integrated circuit (IC). Motor drivers act as current amplifiers since they take a low-current control signal and provide a higher-current signal. This higher current signal is used to drive the motors. For to know about IC function, pin description and datasheet refer L293D. In this project the arduino digital pin 2 and 3 is connected to the Input A 2nd and 7th pin of L293 D respectively and the arduino digital pin 4 an 5 is connected to the input B 10th and 15th of L293 D IC respectively. Enable pin of L293D is supplied with 5V and the 4, 5, 12, 13 pins are connected to ground. 8th pin of L293D IC is supplied with 12V for motor power.

GEARED DC MOTOR:

The 12V DC Geared Motor can be used in variety of robotics applications and is available with wide range of RPM and Torque, which allow your robot to move based on the control signal it receives from the motor driver IC. Two geared DC motors are used to run the robot. Left motor positive and negative is connected to output A side pin 3rd and 6th of L293D IC and right motor positive and negative is connected to output B pin 11th and 14th of L293D IC respectively.

XBEE S1 MODULE:

In this part Xbee is used as transceiver which is mounted on the robot, it follows the serial communication with the arduino. TX of xbee is connected with RX of arduino and RX of xbee to TX of arduino.

WORKING DESCRIPTION:

CONFIGURING XBEE MODULES:

The coolterm terminal software is used to configure xbee. In order to make pc to communicate directly with the xbee, even arduino board can be used by removing the controller IC or you can just upload empty simple sketch to the arduino boards, which makes xbee to directly communicate with computer not to arduino. Where connection between arduino and xbee should be like TX of xbee to TX of arduino and RX of Xbee to RX of arduino.

After that open up the coolterm application and choose connection -> options -> serial port select the comport and set the baud rate and go to Terminal option select the Local echo check box to display what you type and click OK to save changes.

Connection Option Box for Cool Term Application

To configure xbee the following AT commands should be used, at first make the xbee to enter into a command mode by entering +++ in the terminal once it gets OK then follow with the AT commands

First off, XBEE radios only operate at a given baud rate, this is the number of bits per second that the XBEE can send. A brand new xbee will default to 9600bps, which is pretty slow. We can change the baud rate, by changing the ATBD register. Both of our XBEEs have to be the same baud rate to talk to one another. The available baud rates (and corresponding ATBD value) are:

1 = 2400bps

2 = 4800bps

3 = 9600bps

4 = 19200bps

5 = 38400bps

6 = 57600 bps

7 = 115200 bps

Here we have set with baud rate 9600, so in order to set that baud rate the command should be used as

ATBD3

The next parameter of interest is the Personal Area Network ID. This is a number shared amongst each XBEE in a network. For now, we are only using 2 XBEEs, but we could have many, many more in a single network. XBEEs on different networks do not “see” each other. The default PAN is 3332, so you should avoid that number. The PAN ID is stored in ATID.

We have set with the following ID

ATID1001

Once both of our XBEEs are on the same network, we can give each one an address number, denoted by ATMY. We can also set the destination address, which is what address number to talk to, denoted ATDL (for destination low, we really don’t need to use the high bytes if we keep our address numbers < 16 bits in length). A sample setup of two XBEEs that will talk directly to one another, at 38.4kbps: Use the following command

ATMY10

ATDL11

The both xbees will be configured as

XBEE1:

ATID1001

ATMY10

ATDL11

ATBD3

XBEE2:

ATID1001

ATMY11

ATDL10

ATBD3

We can also easily set parameters. An important thing to note though is that changes we make are stored in temporary memory, if we power the XBEE device off, they are lost. We need to send ATWR to write the changes to non-volatile memory.

PROJECT DESCRIPTION:

Keypad controlled and Industrial Gas Monitoring Wireless Robot

Make the circuit connections according to the circuit diagram and the description given. At first both the transmitter and the Receiver circuit setup are powered up. The LCD shows the Initial message and starts displaying the direction of the robot. The robot starts moving in direction with respect to the key pressed in the Keypad.

NUMBERS ON KEYPAD	DIRECTION OF ROBOT
2	FORWARD
8	BACKWARD
4	LEFT
6	RIGHT
1	CO GAS MEASUREMENT FROM MQ7
3	AIR QUALITY MEASUREMENT FROM MQ135

With respect to value detected from keypad by arduino the data’s are transmitted wirelessly through the xbee, where the data are received by xbee mounted on robot and the data is given to microcontroller to process and control the direction of robot by giving input to motor driver L293D IC from digital pins of microcontroller by making the pin high. As our main purpose is to measure air quality and CO gas, so the robot is moved to particular place and stopped and keypad number to measure the gases is pressed the control signal which is sent instructs to measure the gas content in air. When the key 1 is pressed it request for the reading from the mq7 sensor, sensitive material of MQ-7 gas sensor is SnO2, which with lower conductivity in clean air. It make detection by method of cycle high and low temperature, and detect CO at low temperature(heated by 1.5V).The sensor’s conductivity gets higher along with the CO gas concentration rising. At high temperature (heated by 5.0V), it cleans the other gases adsorbed at low temperature.

The measured sensor gas value is transmitted to the user side and the gas measured is displayed on the LCD.

PROGRAMMING DESCRIPTION:

Transceiver Program (Controlling side):

The Arduino code loads the LiquidCrystal.h to handle LCD display and Keypad.h to handle the keypad input. The Keypad pattern and the arduino pins for connecting keypad row and column is defined.

In the setup() function the baud rate for serial communication with the xbee module is set to 9600 bits per second using begin() method on Serial class.

The loop() function is called in which the key press is detected is read and stored in variables declared for it. According to the key pressed from keypad, by following the condition respective data is sent to the xbee using pritln() function.

Keypad Loop Function

In the loop() function, on pressing the key 1 or 3 it looks for the gas value measurement and sent wirelessly by Xbee, as the data received is a byte it is converted to integer using atoi function and stored in the buffer.

Keypad Interface Box

Transceiver program (Robot Side):

Motor pins are defined which is connected with the arduino to motor driver IC. In the setup() function begin() is initialized with 9600 baud rate to receive the serial data from xbee. Motor pin modes are defined as output pin.

The loop() function is called in which it continuously checks for the incoming serial data, if serial data is available, the data is read using serial.read() function and stored in the variable. Then stored data is checked with the condition mentioned. Then with respect to conditions function call for robot movement is carried out.

When the command is received to measure the value of gas, the values are measured by reading the value from the respective sensor.

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Project Source Code

###



//Program to 


int Sensor_value = 0;


char msg = ' ';


#define Left_motor1  2

#define Left_motor2  3

#define Right_motor1 4

#define Right_motor2  5


void move_forward();

void move_backward();

void turn_left();

void turn_right();

void robo_stop();


void setup() 

{

 Serial.begin(9600);

 pinMode(Left_motor1, OUTPUT);

 pinMode(Left_motor2, OUTPUT);

 pinMode(Right_motor1, OUTPUT);

 pinMode(Right_motor2, OUTPUT);

}


void loop() 

{

  if(Serial.available() > 0) 

  {

    msg = Serial.read();

    if(msg == 'C')

    {

       Sensor_value = analogRead(0);

       //Serial.print("MQ135 = ");

       Serial.println(Sensor_value);

       Serial.println('n');

       //delay(50);

    }

    if(msg == 'A')

    {

      int mq7_digital = analogRead(1);

     // Serial.print("MQ7 = ");

      Serial.println(mq7_digital);

      Serial.println('n');

    }

    

    if(msg == 'F')

    {

      Serial.print("Forward");

      move_forward();

    }


    if(msg == 'B')

    {

      Serial.print("Backward");

      move_backward();

    }


    if(msg == 'R')

    {

      Serial.print("Right");

      turn_right();

    }


    if(msg == 'L')

    {

      Serial.print("Left");

      turn_left();

    }

    if(msg == 'S')

    {

      Serial.print("Stop");

      robo_stop();

    }

  }

  //delay(500);

}


void move_forward()

{

  digitalWrite(Left_motor1, HIGH);

  digitalWrite(Left_motor2, LOW);

  digitalWrite(Right_motor1, HIGH);

  digitalWrite(Right_motor2, LOW);

}


void move_backward()

{

  digitalWrite(Left_motor1, LOW);

  digitalWrite(Left_motor2, HIGH);

  digitalWrite(Right_motor1, LOW);

  digitalWrite(Right_motor2, HIGH);

}


void turn_right()

{

  digitalWrite(Left_motor1, HIGH);

  digitalWrite(Left_motor2, LOW);

  digitalWrite(Right_motor1, LOW);

  digitalWrite(Right_motor2, LOW);

}


void turn_left()

{

  digitalWrite(Left_motor1, LOW);

  digitalWrite(Left_motor2, LOW);

  digitalWrite(Right_motor1, HIGH);

  digitalWrite(Right_motor2, LOW);

}


void robo_stop()

{

  digitalWrite(Left_motor1, LOW);

  digitalWrite(Left_motor2, LOW);

  digitalWrite(Right_motor1, LOW);

  digitalWrite(Right_motor2, LOW);

}


###

Circuit Diagrams

Keypad_controlled-_and_Industrial_Gas_Monitoring_Wireless_Robot_Circuit_Diagram
Keypad_controlled-_and_Industrial_Gas_Monitoring_Wireless_Robot_Circuit_Diagram-2-min