SR04

robotboy

Hi guys, i got 5 Sr04 sensors and cant seem to get them working with the code i wrote. Here is the code:


#include <LiquidCrystal.h>
#include <Servo.h>
#define trigPin 24
#define echoPin 25
#define Reye 22
#define Leye 23
Servo Pan;
Servo Tilt;
Servo Right;
Servo Left;
LiquidCrystal lcd(35, 36, 37, 38, 39, 40);

void setup() {
pinMode(Reye, OUTPUT);
pinMode(Leye, OUTPUT);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
Serial.begin(9600);
Pan.attach(31);
Tilt.attach(32);
Right.attach(33);
Left.attach(34);

}
void loop() {
digitalWrite(Reye, HIGH);
digitalWrite(Leye, HIGH); // turn the LED on (HIGH is the voltage level)
int sensorValue = analogRead(A0);
float voltage = sensorValue * (5.0 / 1023.0);
Serial.println(voltage);
lcd.setCursor(0, 1);
int duration, distance;
digitalWrite(trigPin, HIGH);
digitalWrite(Reye, HIGH);
digitalWrite(Leye, HIGH);
delayMicroseconds(1000);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = (duration/2) / 29.1;



if (distance >= 200 || distance <= 0){
lcd.print("Wobot ");
Right.write(180);
Left.write(180);
}
if (distance <= 35){
lcd.print("Wow");
Right.write(0);
Left.write(0);

}

else {
lcd.print(distance);
lcd.print(" cm ");
Right.write(180);
Left.write(0);

}
delay(500);
}



If you see whats wrong that would be great!

Martin_H

Hi, first code is easier to read if you use these instructions:



Second, when you say it doesn't work what is the symptom?

robotboy

#include <LiquidCrystal.h>
#include <Servo.h> 
#define trigPin 24
#define echoPin 25
#define Reye 22
#define Leye 23
Servo Pan;
Servo Tilt;
Servo Right;
Servo Left;
LiquidCrystal lcd(35, 36, 37, 38, 39, 40);

void setup() {                
 pinMode(Reye, OUTPUT);
pinMode(Leye, OUTPUT);
 pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT); 
  Serial.begin(9600); 
  Pan.attach(31);
  Tilt.attach(32);
  Right.attach(33);
  Left.attach(34);
   
}
void loop() {
  digitalWrite(Reye, HIGH);
  digitalWrite(Leye, HIGH);  // turn the LED on (HIGH is the voltage level)
  int sensorValue = analogRead(A0);
  float voltage = sensorValue * (5.0 / 1023.0);
  Serial.println(voltage);
   lcd.setCursor(0, 1);
   int duration, distance;
    digitalWrite(trigPin, HIGH);
  digitalWrite(Reye, HIGH);
  digitalWrite(Leye, HIGH);
  delayMicroseconds(1000);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration/2) / 29.1;


   
 if (distance >= 200 || distance <= 0){
    lcd.print("Wobot         :D");
    Right.write(180); 
    Left.write(180); 
    }
 if (distance <= 35){
    lcd.print("Wow");
    Right.write(0); 
    Left.write(0); 
    
    }
 
  else {
    lcd.print(distance);
    lcd.print(" cm ");
    Right.write(180); 
    Left.write(0); 
   
  }
  delay(500);
}

well all it does is drive forward turning right a little bit slowly as it goes forward (might be my cheap servos).

Duane Degn

robotboy wrote: »

i got 5 Sr04 sensors and cant seem to get them working with the code i wrote.

In what way isn't it working? Is any value displayed?

What are expecting that isn't happening?

I notice you have the line:

distance = (duration/2) / 29.1;

Where both distance and duration are integers. I don't use Arduino much but I don't think you're allowed to divide an integer by a floating point number.

robotboy

Duane Degn wrote: »

In what way isn't it working? Is any value displayed?

What are expecting that isn't happening?

I notice you have the line:

distance = (duration/2) / 29.1;

Where both distance and duration are integers. I don't use Arduino much but I don't think you're allowed to divide an integer by a floating point number.

well it doesn't seem to display like it should and when something gets to 35 cm away it would turn.

Duane Degn

robotboy wrote: »

well it doesn't seem to display like it should.

What does it display? What should it display?

Try changing the line I posted above to:

distance = (duration/2) / 29;

It might not be as accurate as you'd like but this takes care of the interger and floating point mixture.

Martin_H

Your delayMicroseconds has an argument of 1000 while the sample code I found online has an argument of 10.

  // Start Ranging
  digitalWrite(TRIGPIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGPIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGPIN, LOW);
  // Compute distance
  float distance = pulseIn(ECHOPIN, HIGH);
  distance= distance/58;
  Serial.println(distance);
  delay(200);

Duane, C++ usually automatically converts from float to int or vice versa depending upon the destination type and the other argument.

PJAllen

http://arduino.cc/forum/index.php/topic,106043.0.html

not really a Parallax-based discussion, this

robotboy

Problem solved.... bad servo plug

Duane Degn

robotboy wrote: »

Problem solved.... bad servo plug

You ought make the change Martin suggested.

robotboy

Ya.... wobot is running live using the SR04 http://www.youtube.com/watch?v=O8wR5FWu5vY

erco

Go wobot! Nicely done, very Wall-E-esque.

robotboy

Thank you!