Changing directions on a robot.

Projects General Guidance
1

Hello,

Im trying to make a robot run a course of sorts, where it goes right, left, right, left, left, left, right. I'm very new to programming so I don't know what I'm doing wrong with my code. I've received a lot of help getting to where I am now, but I'm not sure what's going on. Every time i test it out, it repeats the beginning part of the loop. Not sure why it doesn't just go down the else if statements. Here is my code:

const int AIN1 = 13;
const int AIN2 = 12;
const int PWMA = 11;
const int PWMB = 10;
const int BIN2 = 9;
const int BIN1 = 8;
const int trigPin = 6;
const int echoPin = 5;

int switchPin = 7;

float distance = 0;

int backupTime = 300;
int turnTime = 200;

/*************************************************************************************************/
void setup()
{
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(switchPin, INPUT_PULLUP);
pinMode(AIN1, OUTPUT);
pinMode(AIN2, OUTPUT);
pinMode(PWMA, OUTPUT);
pinMode(BIN1, OUTPUT);
pinMode(BIN2, OUTPUT);
pinMode(PWMB, OUTPUT);

Serial.begin(9600);
Serial.print("We will win, Dr. Gururajan!");
}

/*************************************************************************************************/
void loop()
{
distance = getDistance();

Serial.print("Distance: ");
Serial.print(distance);
Serial.println(" in");

if(digitalRead(switchPin) == LOW){

if(distance < 10){
Serial.print(" ");
Serial.print("Backin' up.");

rightMotor(0);
leftMotor(0);
delay(200);

rightMotor(-255);
leftMotor(-255);
delay(backupTime);

rightMotor(510);
leftMotor(-510);
delay(turnTime);

Serial.print(" ");
Serial.print("Moving...");
rightMotor(255);
leftMotor(255);
}
/********************/
if(distance < 10){
Serial.print(" ");
Serial.print("Backin' up.");

rightMotor(0);
leftMotor(0);
delay(200);

rightMotor(-255);
leftMotor(-255);
delay(backupTime);

rightMotor(-510);
leftMotor(510);
delay(turnTime);

Serial.print(" ");
Serial.print("Moving...");
rightMotor(255);
leftMotor(255);
}
/********************/
if(distance < 10){
Serial.print(" ");
Serial.print("Backin' up.");

rightMotor(0);
leftMotor(0);
delay(200);

rightMotor(-255);
leftMotor(-255);
delay(backupTime);

rightMotor(510);
leftMotor(-510);
delay(turnTime);

Serial.print(" ");
Serial.print("Moving...");
rightMotor(255);
leftMotor(255);
}
/********************/
if(distance < 10){
Serial.print(" ");
Serial.print("Backin' up.");

rightMotor(0);
leftMotor(0);
delay(200);

rightMotor(-255);
leftMotor(-255);
delay(backupTime);

rightMotor(-510);
leftMotor(510);
delay(turnTime);

Serial.print(" ");
Serial.print("Moving...");
rightMotor(255);
leftMotor(255);
}
/********************/
if(distance < 10){
Serial.print(" ");
Serial.print("Backin' up.");

rightMotor(0);
leftMotor(0);
delay(200);

rightMotor(-255);
leftMotor(-255);
delay(backupTime);

rightMotor(-510);
leftMotor(510);
delay(turnTime);

Serial.print(" ");
Serial.print("Moving...");
rightMotor(255);
leftMotor(255);
}
/********************/
if(distance < 10){
Serial.print(" ");
Serial.print("Backin' up.");

rightMotor(0);
leftMotor(0);
delay(200);

rightMotor(-255);
leftMotor(-255);
delay(backupTime);

rightMotor(-510);
leftMotor(510);
delay(turnTime);

Serial.print(" ");
Serial.print("Moving...");
rightMotor(255);
leftMotor(255);
}
/********************/
if(distance < 10){
Serial.print(" ");
Serial.print("Backin' up.");

rightMotor(0);
leftMotor(0);
delay(200);

rightMotor(-255);
leftMotor(-255);
delay(backupTime);

rightMotor(510);
leftMotor(-510);
delay(turnTime);

Serial.print(" ");
Serial.print("Moving...");
rightMotor(255);
leftMotor(255);
}
/********************/
} else{
rightMotor(0);
leftMotor(0);
}
delay(50);
}

/*************************************************************************************************/
void rightMotor(int motorSpeed)
{
if (motorSpeed > 0)
{
digitalWrite(AIN1, HIGH);
digitalWrite(AIN2, LOW);
}
else if (motorSpeed < 0)
{
digitalWrite(AIN1, LOW);
digitalWrite(AIN2, HIGH);
}
else
{
digitalWrite(AIN1, LOW);
digitalWrite(AIN2, LOW);
}
analogWrite(PWMA, abs(motorSpeed));
}

/*************************************************************************************************/
void leftMotor(int motorSpeed)
{
if (motorSpeed > 0)
{
digitalWrite(BIN1, HIGH);
digitalWrite(BIN2, LOW);
}
else if (motorSpeed < 0)
{
digitalWrite(BIN1, LOW);
digitalWrite(BIN2, HIGH);
}
else
{
digitalWrite(BIN1, LOW);
digitalWrite(BIN2, LOW);
}
analogWrite(PWMB, abs(motorSpeed));
}

/*************************************************************************************************/
float getDistance()
{
float echoTime;
float calcualtedDistance;

digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);

echoTime = pulseIn(echoPin, HIGH);

calcualtedDistance = echoTime / 148.0;

return calcualtedDistance;
}

What am I doing wrong?

2

Well, help us help you. What distances are shown on your PC monitor? Could there be a problem comparing your distance (a float) to an integer?

Paul

3

Dear Paul,

The distances shown are in units of inches, but are presented as raw integers (I'm assuming). Is this the kind of information you're looking for?

4

EggMan1234:
Dear Paul,

The distances shown are in units of inches, but are presented as raw integers (I'm assuming). Is this the kind of information you're looking for?

I am looking for the float value you are comparing to the integer value "10".

Paul

5

Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.

Thanks.. Tom.. :slight_smile: