Collision Avoidance with Ultrasonic - Errors

Projects General Guidance
1

Hi all,

Having trouble getting this piece of code to work.

Keep getting the 'too few arguments to function' error in the loop, probably due to my inclusion of the analogRead??

Any help would be appreciated

#include <Servo.h>
//Declare Servos
Servo scanservo; //Ping Sensor Servo
const int motor1 = 12;
const int motor2 = 9;

const int steer1 = 13;
const int steer2 = 8;

const int a = 800;
const int turntime = 500; //Number of milliseconds to turn when turning
const int pingPin = 4; //Pin that the Ping sensor is attached to.
const int echoPin = 5; //Pin that the Ping sensor is attached to.
const int scanservopin = 7; // Pin number for scan servo
const int distancelimit = 10; //If something gets this many inched from
// the robot it stops and looks for where to go.

int steervalue1 = 0;
int steervalue2 = 0;
int drivevalue1 = 0;
int drivevalue2 = 0;
int steerin1 = 14;
int steerin2 = 15;
int drivein1 = 16;
int drivein2 = 17;
//Setup function. Runs once when Arduino is turned on or restarted
void setup()
{
Serial.begin (9600);
scanservo.attach(scanservopin); // Attach the scan servo
pinMode(motor1, OUTPUT);
pinMode(motor2, OUTPUT);
pinMode(steer1, OUTPUT);
pinMode(steer2, OUTPUT);

pinMode(drivein1, INPUT);
pinMode(drivein2, INPUT);
pinMode(steerin1, INPUT);
pinMode(steerin2, INPUT);

//Variable inicialization
digitalWrite(motor1,LOW);
digitalWrite(motor2,LOW);
digitalWrite(steer1,LOW);
digitalWrite(steer2,LOW);
delay(2000); // wait two seconds
}
void loop(){
go(); // if nothing is wrong the go forward using go() function below.
int distance = ping(); // us the ping() function to see if anything is ahead.
drivevalue1 = analogRead(drivein1);
if(drivevalue1 > a && distance > distancelimit){
forward();
return;
}
drivevalue2 = analogRead(drivein2);
if(drivevalue2 > a && distance > distancelimit){
backward();
return;
}
steervalue1 = analogRead(steerin1);
if(steervalue1 > a && distance > distancelimit){
turnleft();
return;
}
steervalue2 = analogRead(steerin2);
if(steervalue2 > a && distance > distancelimit){
backward();
return;
}
if (distance < distancelimit){
stopmotors(); // If something is ahead, stop the motors.
char turndirection = scan(); //Decide which direction to turn.
switch (turndirection){
case 'l':
turnleft(turntime);
break;
case 'r':
turnright(turntime);
break;
case 's':
turnleft(turntime);
break;
}
}
}

int ping(){
long distance, duration;
//Send Pulse
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);
//Read Echo
pinMode(echoPin, INPUT);
duration = pulseIn(echoPin, HIGH);
distance=(duration/2)*0.0341;
Serial.print("Ping: ");
Serial.println(distance);
}
void go(){
digitalWrite(12, HIGH);
digitalWrite(9, LOW);
digitalWrite(3, HIGH);
delay(600);
}
void turnleft(int t){
digitalWrite (13, HIGH);
digitalWrite (8, LOW);
digitalWrite (11, HIGH);
delay(t);
}

void turnright(int t){
digitalWrite (13, LOW);
digitalWrite (8, LOW);
digitalWrite (11, HIGH);
delay(t);
}
void forward(int t){
digitalWrite(12, HIGH);
digitalWrite(9, LOW);
analogWrite (3, HIGH);
delay(600);
}
void backward(int t){
digitalWrite (9, LOW);
digitalWrite (12, LOW);
analogWrite (3, HIGH);
delay(t);
}
void stopmotors(){
digitalWrite (9, HIGH);
digitalWrite (8, HIGH);
digitalWrite (3, HIGH);
digitalWrite (11, HIGH);
delay(600);
}

char scan(){
int leftscanval, centerscanval, rightscanval;
char choice;
//Look left
scanservo.write(30);
delay(300);
leftscanval = ping();
//Look right
scanservo.write(150);
delay(1000);
rightscanval = ping();
//center scan servo
scanservo.write(88);

if (leftscanval>rightscanval && leftscanval>centerscanval){
choice = 'l';
}
else if (rightscanval>leftscanval && rightscanval>centerscanval){
choice = 'r';
}
else{
choice = 's';
}
Serial.print("Choice: ");
Serial.println(choice);
return choice;
}

2

Please post your code within code tags.

Your actual error is " too few arguments to function 'void forward(int)'"
So, you look at the function itself, and see

void forward(int t)

Then you look at any calls to that function and see

forward();

So, it looks like you called it with too few arguments. If you needed a parameter in the forward() function, you would fix it by supplying one in the call.

If you don't actually need a parameter passed to the function, as is the case with your code (it moves forward until you call another function that makes it do something else), you could just change the function to read

void forward();
3

Thanks,

Got it working. It's simple once someone else has pointed out for you! :sweat_smile: