Arduino Robot Code

arduino_robot

/* 
Original code by Nick Brenn
Modified by Marc de Vinck
Make Projects Arduino-based 4WD robot
http://makeprojects.com/Project/Build-your-own-Arduino-Controlled-Robot-/577/1 
 */
#include <AFMotor.h> 
AF_DCMotor motor1(1, MOTOR12_8KHZ); 
AF_DCMotor motor2(2, MOTOR12_8KHZ); 
AF_DCMotor motor3(3, MOTOR12_1KHZ); 
AF_DCMotor motor4(4, MOTOR12_1KHZ); 
const int pingPin = 19; 
// ------------------------------------------------------------------------------
void setup() 
{ 
Serial.begin(9600);                 // set up Serial library at 9600 bps 
motor1.setSpeed(200);               // Sets the speed for all the motors 1 - 4 (255 is the 
maximum speed)      
motor2.setSpeed(200); 
motor3.setSpeed(200); 
motor4.setSpeed(200); 
} 
// ------------------------------------------------------------------------------
float ping ()                       // This is the code that runs the PING ))) Sensor 
{ 
long duration, inches; 
pinMode(pingPin, OUTPUT); 
digitalWrite(pingPin, LOW); 
delayMicroseconds(2); 
digitalWrite(pingPin, HIGH); 
delayMicroseconds(5); 
digitalWrite(pingPin, LOW); 
pinMode(pingPin, INPUT); 
duration = pulseIn(pingPin, HIGH);  
long microsecondsToInches(long microseconds);
inches = microsecondsToInches(duration); 
return inches; 
} // ------------------------------------------------------------------------------
void forward()                    // This function moves all the wheels forward 
{ 
motor1.run(FORWARD); 
motor2.run(FORWARD); 
motor3.run(FORWARD); 
motor4.run(FORWARD); 
} 
// ------------------------------------------------------------------------------
void backward()                    // This function moves all the wheels backwards 
{     
motor1.run(BACKWARD); 
motor2.run(BACKWARD); 
motor3.run(BACKWARD); 
motor4.run(BACKWARD); 
} 
// ------------------------------------------------------------------------------
void haltMotors()                   // This function stops all the motors (It is better to stop 
the motors before changing direction) 
{ 
motor1.run(RELEASE); 
motor2.run(RELEASE); 
motor3.run(RELEASE); 
motor4.run(RELEASE);
} 
// ------------------------------------------------------------------------------
void turnRight()                    // This function turns the robot right
{
motor1.run(FORWARD); 
motor2.run(BACKWARD); 
motor3.run(FORWARD); 
motor4.run(BACKWARD); 
} 
// ------------------------------------------------------------------------------
void loop() {                         // This is the main program that will run over and over
long duration, inches;                // Declare the variables "duration" and "inches"duration = pulseIn(pingPin, HIGH); 
inches = ping();                      // Set the inches variable to the float returned by the 
ping() function. 
Serial.print(inches);
Serial.print("in, ");
Serial.println();
  
while (inches >8){                    // While the robot is 8 inches away from an object. 
inches = ping(); 
forward();                            // Move the robot forward. 
  } 
haltMotors();                         // Stop the motors for 2 seconds, before changing 
direction. 
delay(1000);             
while (inches < 10){                  // Until the robot is 10 inches away from the object, go 
backward. 
inches = ping(); 
backward();                           // Move the robot backward. 
} 
turnRight();                          // Once the robot is done moving backward, turn the robot 
right. 
delay(1500);                          // Note!  Change this value (greater or smaller) to adjust 
how much the robot turns right 
haltMotors(); 
delay(1000); 
} 
long microsecondsToInches(long microseconds){ 
return microseconds / 74 / 2; 
} 

Hi Nick,
Just a quick question. The Ping sensor, HC-SR04, has 4 pins: Vcc, Trig, Echo, Gnd. In your sketch "const int pingPin = 19;" You use pin 19 to connect the sensor to the Arduino. Because it shows pin 19 were you using an Arduino Mega 2560 to run the sketch? And, I don't understand how to set up the HC-SR04 with only one pin. Are both Trig and Echo connected to pin 19 on the Mega 2560? If I am using an Arduino Uno, which pin would I use? Any help would be most appreciated. Thanks.
Dan Urbauer
[email protected]
P.S. Just occurred to me, maybe your not using the HC-SR04, but some other sensor.