Obstacle avoiding robotic car using adafruit motor shield & arduino UNO

This tutorial involves building a roboic car with an ultrasonic sensor that

can detect nearby objects and change its direction to avoid these objects.

The ultrasonic sensor will be attached to a servo motor which is constantly scanning

left and right looking for objects in its way.

Hardware Required:

• Arduino Board

• Adafruit Motor Shield

• Ultrasonic Sensor (HC-SR04)

• DC Motor x2

• Wheel x2

• Chassis plate

• Holder for HC-SR04

• Battery 9V

• Battery cap

• jumper Wires

• Button

Connection of Chassis:

• 
  

• The DC motors attach to the chassis.

• The Arduino attach to the chassis.

• The Motor Shield attach to the Arduino.

• The Servo motor attach to the chassis.

• The HC-SR04 holder attach to Servo.

• The HC-SR04 sensor attach to Servo.

Note: here, I have use breadboard instead of servo, but you can use servo.

About motor shield:

• The motor controllers on this shield are designed to run from 4.5V to 25V.

• There are two places you can get your motor 'high voltage supply' from. One is the DC jack on the Ardiuno board and the other is the 2-terminal block on the shield that is labeled EXT_PWR.

• To connect a motor, simply solder two wires to the terminals and then connect them to either the M1, M2.

• Hobby servos are the easiest way to get going with motor control. They have a 3-pin 0.1" female header connection with +5V, ground and signal inputs. The motor shield simply brings out the 16 bit PWM output lines to two 3-pin headers so that it's easy to plug in and go.

• Power for the Servos comes from the Arduino's on-board 5V regulator, powered directly from the USB or DC power jack on the Arduino.

Reference:

https://learn.adafruit.com/adafruit-motor-shield/overview

https://www.instructables.com/Arduino-Obstacle-Avoiding-Robot-4WD

Connection:

• DC Motors connect to the Motor Shield.

• Left Motors connect to M1(right) (If the motors run backwards, change the (+) and (-) connections).

• Right Motors connect to M2(left).

• The Servo motor connect to the Motor Shield.

• The Servo1 input is connected to the Arduino Digital 10 input

• The Servo2 input is connected to the Arduino Digital 9 input

• Power for the Servos comes from the Arduino's on-board 5V regulator, powered directly from the USB or DC power jack on the Arduino

Note: here i have only 2 DC motors, M1, M2

The HC-SR04 Sensor connections:

• The HC-SR04 Sensor VCC connect to the Arduino +5V

• The HC-SR04 Sensor GND connect to the Arduino Ground

• The HC-SR04 Sensor Trig connect to the Arduino Analog 0

• The HC-SR04 Sensor Echo connect to the Arduino Analog 1

Battery and on / off button connection:

• The (+) from the battery is connect to a leg of the button

• Connect a cable to the other legs of the button. This cable is for Motor Shield (+)

2 seperate DC power supplies for the Arduino and motors.

Plug in the supply for the Arduino into the DC jack, and connect the motor supply to the PWR_EXT block. Make sure the jumper is removed from the motor shield.

• Attach the wheels

Download code and install the arduino library:

Open the new Arduino IDE page

• Delete everything on the page

• Get the code in here link

• Paste empty Arduino IDE page

• First Install the Arduino Library

• The AF_Motor Arduino library

Before you can use the Motor shield, you must install the AF_Motor Arduino library.

• Close the Arduino IDE

Download the library:

https://github.com/adafruit/Adafruit-Motor-Shield-library

• Uncompress the ZIP file onto your desktop

• Check that inside AFMotor is AFMotor.cpp and AFMotor.h files

• Place the AFMotor folder into your arduino sketch folder/libraries folder. For Windows, this will probably be something like MY Documents/Arduino/libraries for Mac it will be something like Documents/arduino/libraries. If this is the first time you are installing a library, you'll need to create the libraries folder. Make sure to call it libraries exactly, no caps, no other name.

The NewPing Arduino Library:

Download the library: https://bitbucket.org/teckel12/arduino-new-ping/downloads

• Uncompress the ZIP file onto your desktop

• Move to the Arduino library folder

• Restart the IDE

• Now you can see the libraries you have installed

• When you verify, you will not see any errors

About Code:

• Using DC Motors with the Motor Shield

• The motor shield can drive up to 2 DC motors bi-directionally. That means they can be driven forwards and backwards.

• To connect a motor, simply solder two wires to the terminals and then connect them to either the M1, M2.

Using the HC-SR04 with the NewPing Library:

NewPing sonar(trigger_pin, echo_pin [, max_cm_distance]);

Example;

NewPing sonar(10, 12, 220);

This initializes NewPing to use pin 10 for trigger output, pin 12 for echo input, with a maximum ping distance of 220 cm. max_cm_distance is optional [default = 500cm]. If connecting using a single pin, specify the same pin for both trigger_pin and echo_pin as the same pin is doing both functions.

Reference:

https://learn.adafruit.com/adafruit-motor-shield/overview

http://playground.arduino.cc/Code/NewPing

Download full code here link:

043-Obstacle-Avoiding-Robot-with-L298N

.r

Download R • 2KB

Result: