HC-SR04 Ultrasonic sensor added to the Arduino Cluster bot.

ClusterBot, the Arduino robot, now with active ultrasonic
distance ranging via the HC-SR04.

ClusterBot finally gets a brain!  In this program, Cluster simply goes straight and shines the LED, but then will rotate left when something comes within the programmed ranged on his.  While rotating left, ClusterBot is still testingfor object, then will go stragiht when there is no longer something in the path.

You may also notice ClusterBot has had some cosmetic surgery.  I took all of his crazy jumpers out and replaced them with much neater custom sized hookup wires.  I also took the entire robot apart and took him off of that ridiculous Pololu round frame.  ClusterBot is much easier to add things to now, plus he's cleaner looking and lighter.

I bought the HC-SR04 ultrasonic sensor on eBay for around $4.  The Parallax Ping, which is a very similar sensor, sells for $30.  Reading on the web, the best I can tell is there are two differences between the two sensors.  The Parallax Ping only requires one data pin, while the HC-SRO4 requires two data pins.  If I am that crunched for pins, I think your money would be better spent on the Arduino Mega than spending an extra $26 dollars for basically the same functionality.  I've also read that some people have found the Ping has a little further range.  I haven't tested the HC-SRO4 out thoroughly yet, but I have seen it measure accurately (within an inch) out to 48 inches.

I'll post the code for the new version of the ClusterBot, but I won't get into the details of the HC-SRO4 until tomorrow.

#include "Ultrasonic.h"
Ultrasonic ultrasonic( 10, 11);

#define PWMA 3
#define AIN1 0
#define AIN2 1
#define PWMB 5
#define BIN1 2
#define BIN2 4
#define STBY 6
#define LED 7
#define SPEAKER 9
#define FREQ 1000

/* Robot should continue straight until an object is within the distance threshold */
/* Sorry for the superflous code at the bottom - I need to get those functions */
/* into a header file  */

/* The robot should move forward and have a steady green LED until something is 7 inches in front of the sensor.
   Then the robot should stop and rotate left until there is not an object within 7 inches anymore               */

void setup() {
 
pinMode(PWMA,OUTPUT);
pinMode(AIN1,OUTPUT);
pinMode(AIN2,OUTPUT);
pinMode(PWMB,OUTPUT);
pinMode(BIN1,OUTPUT);
pinMode(BIN2,OUTPUT);
pinMode(STBY,OUTPUT);
pinMode(LED,OUTPUT);

}

void loop() {
 
  startUp();
  while(ultrasonic.Ranging(INC) < 9) {
    rotateLeft();
    digitalWrite(LED,HIGH);
    tone(SPEAKER,FREQ);
    delay(20);
    digitalWrite(LED,LOW);
    noTone(SPEAKER);
    delay(20);
  }
  goForward();
  digitalWrite(LED,HIGH);
 
 
}
void goForward ()
{
  digitalWrite (AIN1,HIGH);
  digitalWrite (AIN2,LOW);
  analogWrite(PWMA,233);
  digitalWrite (BIN1,HIGH);
  digitalWrite (BIN2,LOW);
  analogWrite(PWMB,255); 
}

void goBackward ()
{
  digitalWrite (AIN1,LOW);
  digitalWrite (AIN2,HIGH);
  analogWrite(PWMA,233);
  digitalWrite (BIN1,LOW);
  digitalWrite (BIN2,HIGH);
  analogWrite(PWMB,255); 
}

void rotateRight ()
{
  digitalWrite (AIN1,HIGH);
  digitalWrite (AIN2,LOW);
  analogWrite(PWMA,255);
  digitalWrite (BIN1,LOW);
  digitalWrite (BIN2,HIGH);
  analogWrite(PWMB,255); 
}

void rotateLeft ()
{
  digitalWrite (AIN1,LOW);
  digitalWrite (AIN2,HIGH);
  analogWrite(PWMA,255);
  digitalWrite (BIN1,HIGH);
  digitalWrite (BIN2,LOW);
  analogWrite(PWMB,255); 
}

void veerLeft ()
{
  digitalWrite (AIN1,HIGH);
  digitalWrite (AIN2,LOW);
  analogWrite(PWMA,190);
  digitalWrite (BIN1,HIGH);
  digitalWrite (BIN2,LOW);
  analogWrite(PWMB,255); 
}

void veerRight ()
{
  digitalWrite (AIN1,HIGH);
  digitalWrite (AIN2,LOW);
  analogWrite(PWMA,255);
  digitalWrite (BIN1,HIGH);
  digitalWrite (BIN2,LOW);
  analogWrite(PWMB,190); 
}

void applyBrakes ()
{
  digitalWrite (AIN1,HIGH);
  digitalWrite (AIN2,HIGH);
  analogWrite(PWMA,255);
  digitalWrite (BIN1,HIGH);
  digitalWrite (BIN2,HIGH);
  analogWrite(PWMB,255); 
}

void startUp ()
{
  digitalWrite(STBY,HIGH);
}

void turnAround()
{
  rotateLeft();
  delay(1370);
}

void shutDown ()
{
  digitalWrite(STBY,LOW);
}