Couldn't manage to make URM37 sensor works with Arduino uno

Other Hardware Sensors
1

Hello.
I am making my first robot. The Devastator Robot from Dfrobot with an Arduino uno.

I manage to make the servo works, but not the URM37 V5.0 sensor on it.

The most strange thing is, depending of code i use, i have differents results.

Here are my connections :
On my sensor :

On my Arduino Uno :

I connect the USB cable on the board the read the result of the code execution in the log.

When is use the NewPing library with this code, all ping are a 0

#include <Servo.h> 
#include <NewPing.h>  

#define TRIG_PIN 4 
#define ECHO_PIN 5 
#define MAX_DISTANCE 200 
#define MAX_SPEED 200 // sets speed of DC  motors
#define MAX_SPEED_OFFSET 20

int E1 = 5;     //M1 Speed Control
int E2 = 6;     //M2 Speed Control
int M1 = 4;     //M1 Direction Control
int M2 = 7;     //M1 Direction Control

NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE); 
Servo myservo;   

int distance = 100;
boolean goesForward=false;
int speedSet = 0;

void setup(void) 
{ 
  Serial.begin(9600);
  myservo.attach(8);  
  myservo.write(115); 
  delay(2000);
  distance = readPing();
  delay(100);
  distance = readPing();
  delay(100);
  distance = readPing();
  delay(100);
  distance = readPing();
  delay(100);
  Serial.println(distance);
} 
 
void loop(void) 
{
 int distanceR = 0;
 int distanceL =  0;
 delay(40);
 
 if(distance<=20)
 {
  stop();
  delay(100);
  moveBackward();
  delay(500);
  stop();
  delay(200);
  distanceR = lookRight();
  delay(200);
  distanceL = lookLeft();
  delay(200);

  if(distanceR>=distanceL)
  {
    turnRight();
    stop();
  }else
  {
    turnLeft();
    stop();
  }
 }else
 {
  moveForward();
 }
 distance = readPing();
}

void turnRight() {
 
  analogWrite (E1,155);
  analogWrite (E2,155); 
  digitalWrite(M1,LOW);    
  digitalWrite(M2,HIGH); 
  delay(1400);
  digitalWrite(M1,HIGH);    
  digitalWrite(M2,HIGH);
} 

void turnLeft()
{
  analogWrite (E1,155);
  analogWrite (E2,155); 
  digitalWrite(M1,HIGH);     
  digitalWrite(M2,LOW);
  delay(1600);
  digitalWrite(M1,HIGH);    
  digitalWrite(M2,HIGH);
}

void stop(void)                    //Stop
{
  digitalWrite(E1,0); 
  digitalWrite(M1,LOW);    
  digitalWrite(E2,0);   
  digitalWrite(M2,LOW);    
}   

void moveBackward() 
{
  goesForward=false;
  digitalWrite(M1,LOW);    
  digitalWrite(M2,LOW);  
  for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2) // slowly bring the speed up to avoid loading down the batteries too quickly
  {
    analogWrite (E2,speedSet);   
    analogWrite (E1,speedSet+MAX_SPEED_OFFSET);
    delay(5);
  }
}  

int lookRight()
{
    myservo.write(50); 
    delay(500);
    int distance = readPing();
    delay(100);
    myservo.write(115); 
    Serial.print("Looking right. Distance:");
    Serial.println(distance);
    return distance;
}

int lookLeft()
{
    myservo.write(170); 
    delay(500);
    int distance = readPing();
    delay(100);
    myservo.write(115); 
    Serial.print("Looking left. Distance:");
    Serial.println(distance);
    return distance;
}

int readPing() { 
  delay(70);
  int cm = sonar.ping_cm();
  if(cm==0)
  {
    cm = 250;
  }
  return cm;
}

void moveForward() {

 if(!goesForward)
  {
    goesForward=true;
    digitalWrite(M1,HIGH);    
    digitalWrite(M2,HIGH); 
   for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2) // slowly bring the speed up to avoid loading down the batteries too quickly
   {
     analogWrite (E2,speedSet);      //PWM Speed Control
     analogWrite (E1,speedSet+MAX_SPEED_OFFSET);
     delay(5);
   }
  }
}

But when i use the PWM trigger mode code from DFRobot on URM37 guide

The ping stay at 6cm, and approaching my hand close to the sensor make it change for 2cm
Impossible to have something beyond 6 cm.

// # Editor     : roker
// # Date       : 05.03.2018

// # Product name: URM V5.0 ultrasonic sensor
// # Product SKU : SEN0001
// # Version     : 1.0

// # Description:
// # The Sketch for scanning 180 degree area 2-800cm detecting range
// # The sketch for using the URM37 PWM trigger pin mode from DFRobot
// #   and writes the values to the serialport
// # Connection:
// #       Vcc (Arduino)    -> Pin 1 VCC (URM V5.0)
// #       GND (Arduino)    -> Pin 2 GND (URM V5.0)
// #       Pin 3 (Arduino)  -> Pin 4 ECHO (URM V5.0)
// #       Pin 5 (Arduino)  -> Pin 6 COMP/TRIG (URM V5.0)

// # Working Mode: PWM trigger pin  mode.

int URECHO = 5;         // PWM Output 0-50000US,Every 50US represent 1cm
int URTRIG = 4;         // trigger pin

unsigned int DistanceMeasured = 0;

void setup()
{
  //Serial initialization
  Serial.begin(9600);                        // Sets the baud rate to 9600
  pinMode(URTRIG, OUTPUT);                   // A low pull on pin COMP/TRIG
  digitalWrite(URTRIG, HIGH);                // Set to HIGH
  pinMode(URECHO, INPUT);                    // Sending Enable PWM mode command
  delay(500);
  Serial.println("Init the sensor");

}
void loop()
{
  Serial.print("Distance=");
  digitalWrite(URTRIG, LOW);
  digitalWrite(URTRIG, HIGH);              

  unsigned long LowLevelTime = pulseIn(URECHO, LOW) ;
  if (LowLevelTime >= 50000)              // the reading is invalid.
  {
    Serial.println("Invalid");
  }
  else
  {
    DistanceMeasured = LowLevelTime / 50;  // every 50us low level stands for 1cm
    Serial.print(DistanceMeasured);
    Serial.println("cm");
  }

  delay(200);
}

I don't understand what's wrong. My connections, the code ?

2

You will have to host the images elsewhere. The site you used is way too spammy.

I suggest uploading the images here.

3

Ok, i have edited the message.

1 Like
4

Found it.
Cant set echo and trigger pin same as constants values of motors in the code.

Why ?
I don't know.

1 Like
5

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.