Check the code nd tell what wrong with this code...plz help

Other Hardware Sensors
1

#include <Servo.h>

const int servoPin = 3;

Servo servo;

int angle =0;
int angle1 =180;
int val = 0;

int trigPin = 11; // Trigger
int echoPin = 12; // Echo
long duration, cm;
int ledPin = 2;

int trigPin1 = 8; // Trigger
int echoPin1 = 9; // Echo
long duration1, cm1;

void setup() {
//Serial Port begin
Serial.begin (9600);

// Servo motor
servo.attach(servoPin);

// LED
pinMode(ledPin, OUTPUT);

// Sensor 1
//Define inputs and outputs
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);

// Sensor 2
//Define inputs and outputs
pinMode(trigPin1, OUTPUT);
pinMode(echoPin1, INPUT);

}

void loop() {

// ============= sensor 1 ==========================
// The sensor is triggered by a HIGH pulse of 10 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
digitalWrite(trigPin, LOW);
delayMicroseconds(10);
digitalWrite(trigPin, HIGH);
delayMicroseconds(20);
digitalWrite(trigPin, LOW);

// Read the signal from the sensor: a HIGH pulse whose
// duration is the time (in microseconds) from the sending
// of the ping to the reception of its echo off of an object.
pinMode(echoPin, INPUT);
duration = pulseIn(echoPin, HIGH);

// Convert the time into a distance
cm = (duration/2) / 29.1;
Serial.print("servi: ");
Serial.print(cm);// Divide by 29.1 or multiply by 0.0343
Serial.print("angle: ");
Serial.println(angle);
if(cm < 30 ){

for( angle ; angle <=180; angle++){
servo.write(angle);
delay(20);
}
delay(2000);
}

angle = 0;
Serial.print("angle1: ");
Serial.println(angle);;

//
if(cm > 30){
for( angle1; angle1 >=0; angle1--){
servo.write(angle1);
delay(20);
}
delay(2000);
}
angle1=180;
Serial.print("angle2: ");
Serial.println(angle);

// }
/* if(cm< 20 && cm >0 && angle ==0){
servo.write(180);
angle = 180;
delay(15); } */
// }
//delay(250);

// ======================= sensor2 ================================

// The sensor is triggered by a HIGH pulse of 10 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
digitalWrite(trigPin1, LOW);
delayMicroseconds(5);
digitalWrite(trigPin1, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin1, LOW);

// Read the signal from the sensor: a HIGH pulse whose
// duration is the time (in microseconds) from the sending
// of the ping to the reception of its echo off of an object.
pinMode(echoPin1, INPUT);
duration = pulseIn(echoPin1, HIGH);

// Convert the time into a distance
cm1 = (duration/2) / 29.1; // Divide by 29.1 or multiply by 0.0343

Serial.print(" sensor_2: ");
Serial.print(cm1);
Serial.println();

if(cm1 < 10 && cm1 >= 0){

digitalWrite(ledPin, HIGH); // turn the LED on (HIGH is the voltage level)
}
if(cm1 > 10){

digitalWrite(ledPin, LOW);
servo.write(0);
}

delay(250);

}

in this experiment i used servo motor nd sonar sensor... the code will be doing when sonar distance is less than 30 cm then servo motor rotate 0 to 180 degree.. and when sonar sensor distance is greater than 30 cm degree then servo motor rotate in reverse order 180 to 0 degree.............. but problem comes in servo motor when i run the code and the distance is less then 30 cm then motor rotate continuously 0 to 180 and 180 to 0.... its same as when distance is greater than 30 cm.... when i run for() loop without if condition, servo motor worked properly but when i used for() loop with sonar sensor distance ... the servo motor did not worked properly

2

Please edit your post to add code tags, after reading the "How to use this forum" post.

Post a wiring diagram (hand drawn, not Fritzing).

Explain what you mean by "the servo motor did not worked properly". What did you expect to happen, and what happened instead?

3

Make sure your power supply is not just from the USB port. There is not enough power to run the servo without disrupting the voltage level. If you are just running from the USB interface, use an external power supply rated at 1 A or more.

4

It’s wirth having a look at some of the debugging tips - Such adding the odd print statement to the serial monitor so you can be sure your code is reaching a certain point or the values of variables are what you expect.
Much more learning happens when you sort things out yourself , software rarely works first time ( well mine doesn’t)