Robotics Training Manual

Transcription

1 by Engr. Kyle Erald Hizon 1

2 Overview L298 Dual H-Bridge Motor driver To control different types of motors, you will first need a motor driver. A good example would be the L298 Dual H-Bridge Motor Driver, it can handle 2A and is compatible with the Arduino. This allows you to control the speed and direction of two DC Motors or one single bipolar Stepper Motor with ease. The L298N H-bridge module can be used with motors that have a voltage of between 5V and 35V DC. There is also an onboard 5V regulator, so if your supply voltage is up to 12V you can also source 5V from the board. Materials Experiment 1: Motor Control The materials that you will be needing for this experiments are the following: 1. L298 Dual H-Bridge Motor Driver 2. DC Motor - 2 pc 3. Connecting Wires 4. Arduino 5. Arduino USB Connector 6. Laptop/Computer 7. Power Source Pinouts In order for us to utilize the Motor Driver, we need to understand the connections that are available from the board. From the image on your left you will see the following: (From Left to Right) MotorA - Connection for Motor A (Vcc+GND) VMS - Supply Voltage (5-35V) GND - Ground Connection 5V - 5V source from on Board Regulator MotorB - Connection for Motor B (Vcc+GND) 2

3 From the image on your right you will see: (From Top to Bottom) ENA - MotorA Enable Pin IN1 - MotorA Direction 1 Pin IN2 - MotorA Direction 2 Pin IN3 - MotorB Direction 1 Pin IN4 - Motor B Direction 2 Pin ENB - MotorB Enable Pin GND - Ground Pin +5V - 5V source from on Board Regulator Control Instructions Now that we are familiar with the Pinouts of the board lets now show you how to utilize the pins that we have identified. Enable Motor A - Set ENA to High Disable Motor A - Set ENA to Low Direction 1 - Set IN1 to HIGH and Set IN2 to LOW Direction 2 - Set IN1 to LOW and Set IN2 to HIGH Break/Stop - Set IN1 and IN2 to HIGH Coasting/Standby - Set IN1 and IN2 to LOW The process is same for Motor B. Note: If you are using two motors for control, you must set the pins for both motors for each direction or condition that you want it to be. Let s Begin! To start controlling your DC Motor, we need to connect the control pins to the designated Arduino Pins. Arduino Pin Motor Driver Pin 10 < ENA 2 < IN1 3 < IN2 4 < IN3 5 < IN4 9 < ENB GND < GND If you want to supply your Arduino board with the Motor Driver s 5V supply: 5V < V 3

4 Next, Let s connect your DC Motors and Supply Power to the Motor Driver. VCC+GND Supply GND VCC+GND MOTOR A VMS GND +5V MOTOR B Your connection should look something like on the picture on your right. Now that all your connections are set we can now start uploading the code to your Arduino. Arduino Code /** * Bruno Santos, 2013 * feiticeir0@whatgeek.com.pt * Small code to test DC motors - 2x with a L298 Dual H-Bridge Motor Driver * Free to share **/ //Testing the DC Motors //Define Pins //Motor A int enablea = 10; int pina1 = 2; int pina2 = 3; //Motor B int enableb = 9; int pinb1 = 4; int pinb2 = 5; void setup() Serial.begin (9600); //configure pin modes pinmode (enablea, OUTPUT); pinmode (pina1, OUTPUT); pinmode (pina2, OUTPUT); pinmode (enableb, OUTPUT); pinmode (pinb1, OUTPUT); pinmode (pinb2, OUTPUT); 4

5 void loop() //enabling motor A Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); //do something //forward Serial.println ( Forward ); digitalwrite (pina1, HIGH); digitalwrite (pina2, LOW); //5s forward delay (5000); //reverse digitalwrite (pina1,low); digitalwrite (pina2,high); //5s backwards delay (5000); //stop digitalwrite (enablea, LOW); delay (5000); //enabling motor B //Since motor B is mounted reversed, PINs must be exchanged Serial.println ( Enabling Motor A ); digitalwrite (enableb, HIGH); //do something //forward Serial.println ( Forward ); digitalwrite (pinb1, LOW); digitalwrite (pinb2, HIGH); //5s forward delay (5000); //reverse digitalwrite (pinb1,high); digitalwrite (pinb2,low); //5s backwards delay (5000); //stop digitalwrite (enableb, LOW); delay (5000); This program will simulate your DC Motors by first enabling Motor A for 5 seconds then it will reverse Motor A for another 5 seconds then it will stop for 5 seconds then do the same thing for Motor B. So that s it guys! Make sure to play around the code so that you can create your own program for your own Project! 5

6 Experiment 2: Joystick Control Overview Keyes Joystick Just like a joystick on game console. You can control x, y and z dimensions input by this joystick module. It can be considered as combination of potentiometers and one button. Data type of the x, y dimensions are analog input signals and z dimension is digital input signal. Thus the x and y ports connect to analog pins of Sensor Shield, while z port connects to digital pin. Materials The materials that you will be needing for this experiments are the following: 1. Keyes Joystick 2. Breadboard 3. Connecting Wires 4. Arduino 5. Arduino USB Connector 6. Laptop/Computer Pinouts and Connection In order for us to utilize the Joystick, we need to understand the connections that are available from the Module. From the image on your left you will see the following: (From Top to Bottom) GND - Ground Pin +5V - 5V Pin ( Supply 5V here ) VRx - 5kOhm Potentiometer X-Axis VRy - 5kOhm Potentiometer Y-Axis SW - Normally Open Button (Z-Axis) Now that we are familiar with the Pins of this module we can now discusss the connection from the module to the Arduino 6

7 Follow the Pin Layout indicted in the table below: Arduino Pin Joystick Pin GND< GND +5V < V A0 < VRx A1 < VRy 8 < SW Your physical connetion should look something similar from the picture on your right. Arduino Code // analog int pin_x = 0; int pin_y = 1; // digital int pin_switch = 8; void setup() Serial.begin(9600); pinmode(pin_switch, INPUT); void loop() int x = analogread(pin_x); int y = analogread(pin_y); int b = digitalread(pin_switch); Serial.print( X: ); Serial.print(x); Serial.print(, ); Serial.print( Y: ); Serial.print(y); Serial.print(, ); Serial.print( B: ); Serial.print(b); Serial.print( \n ); This code will let you test the module using the Serial Monitor in the Arduino, this will be furthered discussed on the next section. 7

8 Serial Monitor Testing Now that we have completed all the wiring and uploaded our program to the Arduino, the next thing we need to do now is test our Module using the Serial Monitor. Simply open the Serial Monitor, that will located on the upper right of your Arduino application. ( See picture ) From the serial monitor, we can see the format of the data that is being displayed on our window X:<Value>,Y:<Value>,B:<Value> Now, Let s try to move the joystick to the right and upward to test the X and Y Axes Notice how the values of the change on the Xaxis as we move the joystick to the right Notice how the values of the change on the Yaxis as we move the joystick upward 8

9 Notice how the value of the Button (B) changes from 1 to 0 when the Z-axis is pressed. After testing the X, Y, and Z inputs from the Module we can now concluded this experiement. Make sure to play around the code so that you can create your own program for your own Project! 9

10 Experiment 3: Joystick+Motor Control Overview For this experiment we will be integrating what we have learned from Experiment #1 and Experiment #2 Combining the two experiements will give an idea on how to integrate two systems into a single device. We will be installing the Motor control on your Robot Chasis and we will control the Robot using the Joystick that we have learned to operate on the previous experiements. Materials The materials that you will be needing for this experiments are the following: 1. Keyes Joystick 2. L298 Dual H-Bridge Motor Driver 3. DC Motor - 2 pc 4. Breadboard 5. Connecting Wires 6. Arduino 7. Arduino USB Connector 8. Laptop/Computer 9. Power Source Wheeled Robot Chasis Kit Connections We will be showing you here where to connect the Pins of the two module that we will be integrating to the Arduino s Pins. The picture on the left shows the way we connected to Pin Layout but you can always have your own way of connecting the layout that will be listed here. Arduino Pin Joystick Pin GND< GND +5V < V A0 < VRx A1 < VRy 8 < SW 10

11 Motor Controller Module: Arduino Pin Motor Driver Pin 10 < ENA 2 < IN1 3 < IN2 4 < IN3 5 < IN4 9 < ENB GND < GND 5V < V Arduino Code Motor Terminals and Supply Terminals VCC+GND Supply GND VCC+GND MOTOR A VMS GND +5V MOTOR B //Define Pins //Motor A int enablea = 10; int pina1 = 2; int pina2 = 3; //Motor B int enableb = 9; int pinb1 = 4; int pinb2 = 5; // analog int pin_x = 0; int pin_y = 1; // digital int pin_switch = 8; void setup() Serial.begin (9600); //configure pin modes pinmode (enablea, OUTPUT); pinmode (pina1, OUTPUT); pinmode (pina2, OUTPUT); pinmode (enableb, OUTPUT); pinmode (pinb1, OUTPUT); pinmode (pinb2, OUTPUT); void loop() int x = analogread(pin_x); int y = analogread(pin_y); //FORWARD if(y<400) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Forward ); digitalwrite (pina1, HIGH); digitalwrite (pina2, LOW); digitalwrite (pinb1, LOW); digitalwrite (pinb2, HIGH); 11

12 //BACKWARD if(y>600) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Reverse ); digitalwrite (pina1,low); digitalwrite (pina2,high); digitalwrite (pinb1,high); digitalwrite (pinb2,low); //LEFT if(x<400) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Left ); digitalwrite (pina1, HIGH); digitalwrite (pina2, LOW); digitalwrite (pinb1, HIGH); digitalwrite (pinb2, LOW); //RIGHT if(x>600) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Right ); digitalwrite (pina1, LOW); digitalwrite (pina2, HIGH); digitalwrite (pinb1, LOW); digitalwrite (pinb2, HIGH); else //stop Serial.println ( Stopping ); digitalwrite (enablea, LOW); digitalwrite (enableb, LOW); Take note that these codes are just the integration of the two codes that we have previously discussed on the past experiments. This will allow you to control your DC Motors that are connected to your Robot Chasis with your Joystick. Make sure to wire the Joystick with considerable length of cable so you can control it with ease. 12

13 Testing the Integrated System Assuming all connections are correct and you have completed uploading the program to the Arduino then testing this System should be straight forward. The Joystick will be your input device that will designate which direction your robot will move. Make sure to orient your joystick properly Moving the joystick upward will make the robot go forward, your DC Motor should rotate similar to the image above. Moving the joystick downward will make the robot go reverse, your DC Motor should rotate similar to the image above. 13

14 Moving the joystick to the right will make the robot go to the right, your DC Motor should rotate similar to the image above. Moving the joystick to the left will make the robot go to the left, your DC Motor should rotate similar to the image above. So thats it guys! Make sure to play around the code so that you can create your own program for your own Project! 14

15 Overview Experiment 4: Ultrasonic Sensor The US-100 Ultrasonic Distance Sensor Module operates from a wide voltage range and provides both digital and serial data output modes. It features accurate temperature corrected range detection. It can output the distance in millimeters using a serial data output mode. Alternatively, the distance can be calculated by measuring the amount of time that a digital output is held high. This sensor can be used with both 3.3V and 5V microcontrollers and only consumes 2mA when idle. Materials The materials that you will be needing for this experiments are the following: 1. US-100 Ultrasonic Distance Sensor 2. Breadboard 3. Connecting Wires 4. Arduino 5. Arduino USB Connector 6. Laptop/Computer Pinouts and Connection In order for us to utilize the Ultrasonic Sensor, we need to understand the connections that are available from the Module. From the image on your left you will see the following: (From Top to Bottom) VCC - Voltage Supply Pin Trig/Tx - Trigger or Transmit Pin Echo/Rx - Echo or Recieve Pin GND - Ground Pin GND - Ground Pin This Module has two Operation Modes but we will be only utilizing one of the two. 15

16 US-100 in Pulse Width Mode To obtain a distance measurement, set the Trig/TX pin high for at least 50 microseconds then set it low to trigger the measurement. The module will output a high pulse on the Echo/RX line with a width that corresponds to the distance measured. Use your microcontroller to measure the pulse width using microseconds. Use the following formula to calculate the distance: Millimeters = PulseWidth * 34 / 100 / 2 Arduino Code Select the pulse mode by removing the shunt from the operating mode selection jumper. Connect the Trig/TX pin to a digital output 6 on your microcontroller and the Echo/RX pin to a digital input 7. const int trigger=6; const int echo=7; float distance; void setup() Serial.begin(9600); pinmode(trigger,output); pinmode(echo,input); void loop() // Trigger US-100 to start measurement // Set up trigger digitalwrite(trigger,low); delaymicroseconds(5); // Start Measurement digitalwrite(trigger,high); delaymicroseconds(50); digitalwrite(trigger,low); // Acquire and convert to mtrs distance=pulsein(echo,high); distance=distance* 34 / 100 / 2 // send result to UART Serial.println(distance); delay(50); 16

17 Testing the US-100 To start the test of this module, open the Serial Monitor, that will be located on the upper right of your Arduino application. ( See picture ) Afterwards, take note of the serial data that we are recieving from the arduino this data is the distance measured by the Ultrasonic sensor without any objects infront. Now, Let s try to place an object infront of the module, we should recieve a value smaller than the inittial value that we received from the Serial Monitor back when we first opened it. Notice how the value changed when we placed the object close to the Module Notice how the value changed once more after placing it farther than the previous one. So that s it guys! Make sure to play around the code so that you can create your own program for your own Project! 17

18 Experiment 5: Ultrasonic + Robot Control Overview For this experiement we will be integrating the Ultrasonic Sensor to Experiement#3 s Robot Chasis+Joystick System. The goal of this integration is to use the Ultrasonic Sensor as a Distance Detector indicating when our Robot will stop at a certain distance from an object or a wall. Please make sure that you have conducted the previous experiemetns before proceeding to the Ultrasonic+Robot Control Experiement. Materials The materials that you will be needing for this experiments are the following: 1. Keyes Joystick 2. L298 Dual H-Bridge Motor Driver 3. DC Motor - 2 pc 4. Breadboard 5. Connecting Wires 6. Arduino 7. Arduino USB Connector 8. Laptop/Computer 9. Power Source Wheeled Robot Chasis Kit 11. US-100 Ultrasonic Distance Sensor Connections We will be integrating all 3 experiements regarding Motor Controller, Joystick and Ultrasnic sensor for this experiement. The Pin Layout will be as follows: Arduino Pin Joystick Pin GND< GND +5V < V A0 < VRx A1 < VRy 8 < SW US-100 Pin 7 < Echo/RX 6 < Trig/TX GND< GND +5V < Vcc 18

19 Motor Controller Module: Arduino Pin Motor Driver Pin 10 < ENA 2 < IN1 3 < IN2 4 < IN3 5 < IN4 9 < ENB GND < GND 5V < V Arduino Code Motor Terminals and Supply Terminals VCC+GND Supply GND VCC+GND MOTOR A VMS GND +5V MOTOR B //Define Pins //Motor A int enablea = 10; int pina1 = 2; int pina2 = 3; //Motor B int enableb = 9; int pinb1 = 4; int pinb2 = 5; // analog int pin_x = 0; int pin_y = 1; // digital int pin_switch = 8; //ultrasonic const int trigger=6; const int echo=7; float distance; void setup() Serial.begin (9600); //configure pin modes pinmode (enablea, OUTPUT); pinmode (pina1, OUTPUT); pinmode (pina2, OUTPUT); pinmode (enableb, OUTPUT); pinmode (pinb1, OUTPUT); pinmode (pinb2, OUTPUT); //Ultrasonic Pin modes pinmode(trigger,output); pinmode(echo,input); void loop() int x = analogread(pin_x); int y = analogread(pin_y); 19

20 //FORWARD if(y<400) digitalwrite(trigger,low); delaymicroseconds(5); // Start Measurement digitalwrite(trigger,high); delaymicroseconds(50); digitalwrite(trigger,low); // Acquire and convert to mtrs distance=pulsein(echo,high); distance=distance* 34 / 100 / 2; if(distance>150) Serial.println(distance); Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Forward ); digitalwrite (pina1, HIGH); digitalwrite (pina2, LOW); digitalwrite (pinb1, LOW); digitalwrite (pinb2, HIGH); //BACKWARD if(y>600) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Reverse ); digitalwrite (pina1,low); digitalwrite (pina2,high); digitalwrite (pinb1,high); digitalwrite (pinb2,low); //LEFT if(x<400) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Left ); digitalwrite (pina1, HIGH); digitalwrite (pina2, LOW); digitalwrite (pinb1, HIGH); digitalwrite (pinb2, LOW); 20

21 //RIGHT if(x>600) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Right ); digitalwrite (pina1, LOW); digitalwrite (pina2, HIGH); digitalwrite (pinb1, LOW); digitalwrite (pinb2, HIGH); else //stop Serial.println ( Stopping ); digitalwrite (enablea, LOW); digitalwrite (enableb, LOW); Testing the Integrated System Assuming all connections are correct and you have completed uploading the program to the Arduino then testing this System should be straight forward. The Joystick will be your input device that will designate which direction your robot will move BUT if a certain object or a wall is within 150milimeters away from the front of the sensor then the robot will stop. Without any obstruction within 150mm of the sensor the robot should be able to move freely without any trouble. 21

22 Placing an object infront of the robot or encountering a wall within 150mm will paralyze the robot from moving forward but you will be able to move from side to side and also in reverse. So thats it guys! Make sure to play around the code so that you can create your own program for your own Project! 22

23 Overview The Funduino Tracker Sensor comes with 3 IR Line Tracking Sensors. These sensensors just follows lines or light reflected on a surface. The sensor has IR light emitter and detector. The sensor returns the status of the IR light reflected from a surface as ON or OFF. The LED shows the status of the sensor. Experiment 6: Line Tracker Materials The materials that you will be needing for this experiments are the following: 1. Funduino Tracker Sensor 2. Breadboard 3. Connecting Wires 4. Arduino 5. Arduino USB Connector 6. Laptop/Computer Pinouts and Connection For our test we will be needing to connect the Pin Layout as follows From the image on your left you will see the following: (From Top to Bottom) VCC - Supply Pin GND - Ground Pin L - Left Sensor Pin C - Center Sensor Pin R - Right Sensor Pin Line Tracker Arduino VCC 5V GND GND L 10 C 9 R 8 23

24 Arduino Code /* * Verifies the IR Line tracking output * feiticeir0@whatgeek.com.pt * Free to share! */ void setup() Serial.begin (9600); pinmode (10,INPUT); pinmode (9,INPUT); pinmode (8,INPUT); void loop() //read the input int L = digitalread(10); //left sensor int C = digitalread(9); //center sensor int R = digitalread(8); // right sensor //print the values Serial.print (L); Serial.print(, ); Serial.print (C); Serial.print(, ); Serial.println (R); Testing the Line Tracker When not detecting anything the code will output 0 and when detecting it will output 1 24

25 So that s it guys! Make sure to play around the code so that you can create your own program for your own Project! 25

26 Experiment 7: Line Tracker + Robot Control Overview For this experiement, we will be integrating the line tracker to the 3-Wheeled Robot Chasis Kit. The goal of this experiement is to allow the Robot to track a strip of black tape in a surface on it s own or autonomously without human intervention. This is possible by using the line tracker that will detect light that is reflected from a surface. If no light is detected then that means it is in the right path. Materials The materials that you will be needing for this experiments are the following: 1. Funduino Tracker Sensor 2. L298 Dual H-Bridge Motor Driver 3. DC Motor - 2 pc 4. Breadboard 5. Connecting Wires 6. Arduino 7. Arduino USB Connector 8. Laptop/Computer 9. Power Source Wheeled Robot Chasis Kit Connections We will be integrating the Motor Control Experiement#1 and the Line Tracker Experiement#6 together on this Experiment. We will follow the Pin Layout of the two experiements with a few minor changes because we will be utilizing Pulse Width Modulation for our DC Motors. Line Tracker Arduino VCC >5V GND >GND L >4 C >3 R >2 26

27 Motor Controller Module: Arduino Pin Motor Driver Pin 13 < ENA 9 < IN1 10 < IN2 11 < IN3 6 < IN4 12 < ENB GND < GND 5V < V Arduino Code Motor Terminals and Supply Terminals VCC+GND Supply GND VCC+GND MOTOR A VMS GND +5V MOTOR B //Define Pins //Motor A int enablea = 8; int pina1 = 9; int pina2 = 10; //Motor B int enableb = 7; int pinb1 = 11; int pinb2 = 6; void setup() Serial.begin (9600); //configure pin modes pinmode (enablea, OUTPUT); pinmode (pina1, OUTPUT); pinmode (pina2, OUTPUT); pinmode (enableb, OUTPUT); pinmode (pinb1, OUTPUT); pinmode (pinb2, OUTPUT); //line tracker pin modes pinmode (2,INPUT); pinmode (3,INPUT); pinmode (4,INPUT); void loop() //read the input int L = digitalread(4); //left sensor int C = digitalread(3); //center sensor int R = digitalread(2); // right sensor Serial.print (L); Serial.print(, ); Serial.print (C); Serial.print(, ); Serial.println (R); 27

28 //FORWARD if(c==0&&r==1&&l==1) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Forward ); analogwrite (pina1, 30); analogwrite (pina2, 0); analogwrite (pinb1, 0); analogwrite (pinb2, 40); //REVERSE else if(c==0&&r==0&&l==0) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Forward ); analogwrite (pina1, 0); analogwrite (pina2, 30); analogwrite (pinb1, 40); analogwrite (pinb2, 0); //REVERSE else if(c==1&&r==1&&l==1) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Forward ); analogwrite (pina1, 0); analogwrite (pina2, 30); analogwrite (pinb1, 40); analogwrite (pinb2, 0); //LEFT else if(c==0&&l==0&&r==1) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Disabling Motor B ); digitalwrite (enableb, LOW); 28

29 Serial.println ( Left ); analogwrite (pina1, 35); analogwrite(pina2, 0); //LEFT else if(c==1&&l==0&&r==1) Serial.println ( Enabling Motor A ); digitalwrite (enablea, HIGH); Serial.println ( Disabling Motor B ); digitalwrite (enableb, LOW); Serial.println ( Left ); analogwrite (pina1, 35); analogwrite(pina2, 0); //RIGHT else if(c==0&&r==0&&l==1) Serial.println ( Disabling Motor A ); digitalwrite (enablea, LOW); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Right ); analogwrite (pinb1, 0); analogwrite (pinb2, 45); //RIGHT else if(c==1&&r==0&&l==1) Serial.println ( Disabling Motor A ); digitalwrite (enablea, LOW); Serial.println ( Enabling Motor B ); digitalwrite (enableb, HIGH); Serial.println ( Right ); analogwrite (pinb1, 0); analogwrite (pinb2, 45); else //stop Serial.println ( Stopping ); digitalwrite (enablea, LOW); digitalwrite (enableb, LOW); 29

30 Setting Up the Maze We will be needing a maze or a circuit where our robot will try to track down a path that is a black colored line and do it s best to complete the track that we have set up for it. There are things to remember when constructing the Maze for your Robot. 1. The surface must be reflective enough for the infrared light to bounce 2. The width of the black colored path must be alteast 1 inch thick Reminders! If you encounter a problem that your robot is not moving at all please refer to the instructions written here: 1. Check your the PWM value: The code written above sets the speed of the DC Motor at a lower level to ensure that the Robot dosen t go off track these values are seen on your right. These values maybe too low for your DC Motor and may be the reason why your robot will not move. The solution is set the AnalogWrite value to a value that is desirable for you. Serial.println ( Forward ); analogwrite (pina1, 0); analogwrite (pina2, 30); analogwrite (pinb1, 40); analogwrite (pinb2, 0); Example: Before: analogwrite (pinb1, 40); After: analogwrite (pinb1, 150); 30

31 Testing the Integrated System After setting up your maze, it is now time to test your new integrated sytem. When powered on your robot should try to go reverse as it is programmed that way. Place it on the track where the black path is located. At first, when you let go of the robot on it s own it wont really go in a straight path immediately, it may stray from time to time but the code is programmed for the robot to get back on the track The code is designed for smooth curves not very sharp left and right turns. Take note of this so that you will be able to simulate the experiement with no problems. Eventually, the robot will make it s way around the track slowly but surely. So that s it guys! Make sure to play around the code so that you can create your own program for your own Project! 31

32 Overview The Tower Pro SG90 servo is one of the cheapest servo motors that you can find on the market, don t try to rotate the servo motor by hand because this may damage the motor. You need torque to control the position of an object, for example, and this Servo that weights 0.32 oz (9.0 g) can provide at 4.8V a torque of 25.0 oz-in (1.80 kg-cm). At 4.8V, the speed of the servo is 0.12 sec/60. Experiment 8: Servo Motor Materials The materials that you will be needing for this experiments are the following: 1. Tower Pro SG90 2. Connecting Wires 4. Arduino 5. Arduino USB Connector 6. Laptop/Computer Pinouts and Connection Connecting the Tower Pro Servo Motor to the Arduino is pretty simple The Tower Pro has 3 Wires Orange - Control Wire Red - Supply Wire Brown - Ground Wire Simply follow the connection diagram on your left to successfully connect it to your Arduino. We connect the Orange Wire to a Digital Pin 9 of the Arduino, the Red wire goes to the 5V pin of the Arduino and the Brown Wire simply goes to the ground pin. 32

33 Arduino Code The Arduino Code is actually available inside the Arduino IDE; Simply go to File -> Examples -> Servo -> Sweep Or if you don t wanna go through that you can just copy it here: /* Sweep by BARRAGAN < This example code is in the public domain. modified 8 Nov 2013 by Scott Fitzgerald */ #include <Servo.h> Servo myservo; // create servo object to control a servo // twelve servo objects can be created on most boards int pos = 0; // variable to store the servo position void setup() myservo.attach(9); // attaches the servo on pin 9 to the servo object void loop() for (pos = 0; pos <= 180; pos += 1) // goes from 0 degrees to 180 degrees // in steps of 1 degree myservo.write(pos); // tell servo to go to position in variable pos delay(15); // waits 15ms for the servo to reach the position for (pos = 180; pos >= 0; pos -= 1) // goes from 180 degrees to 0 degrees myservo.write(pos); // tell servo to go to position in variable pos delay(15); // waits 15ms for the servo to reach the position This code is pretty simple, once uploaded to your arduino and assuming that you have followed the connections properly, it will simulate the Servo motor. Sequence goes like this: Servo goes from 0 to 180 degrees then Servo goes from 180 to 0 degrees then the whole process repeats. So that s it guys! Make sure to play around the code so that you can create your own program for your own Project! 33